staticperl/perl/pp_sys.c

/*    pp_sys.c
 *
 *    Copyright (C) 1995, 1996, 1997, 1998, 1999,
 *    2000, 2001, 2002, 2003, 2004, 2005, by Larry Wall and others
 *
 *    You may distribute under the terms of either the GNU General Public
 *    License or the Artistic License, as specified in the README file.
 *
 */

/*
 * But only a short way ahead its floor and the walls on either side were
 * cloven by a great fissure, out of which the red glare came, now leaping
 * up, now dying down into darkness; and all the while far below there was
 * a rumour and a trouble as of great engines throbbing and labouring.
 */

/* This file contains system pp ("push/pop") functions that
 * execute the opcodes that make up a perl program. A typical pp function
 * expects to find its arguments on the stack, and usually pushes its
 * results onto the stack, hence the 'pp' terminology. Each OP structure
 * contains a pointer to the relevant pp_foo() function.
 *
 * By 'system', we mean ops which interact with the OS, such as pp_open().
 */

#include "EXTERN.h"
#define PERL_IN_PP_SYS_C
#include "perl.h"

#ifdef I_SHADOW
/* Shadow password support for solaris - pdo@cs.umd.edu
 * Not just Solaris: at least HP-UX, IRIX, Linux.
 * The API is from SysV.
 *
 * There are at least two more shadow interfaces,
 * see the comments in pp_gpwent().
 *
 * --jhi */
#   ifdef __hpux__
/* There is a MAXINT coming from <shadow.h> <- <hpsecurity.h> <- <values.h>
 * and another MAXINT from "perl.h" <- <sys/param.h>. */
#       undef MAXINT
#   endif
#   include <shadow.h>
#endif

#ifdef I_SYS_WAIT
# include <sys/wait.h>
#endif

#ifdef I_SYS_RESOURCE
# include <sys/resource.h>
#endif

#ifdef NETWARE
NETDB_DEFINE_CONTEXT
#endif

#ifdef HAS_SELECT
# ifdef I_SYS_SELECT
#  include <sys/select.h>
# endif
#endif

/* XXX Configure test needed.
   h_errno might not be a simple 'int', especially for multi-threaded
   applications, see "extern int errno in perl.h".  Creating such
   a test requires taking into account the differences between
   compiling multithreaded and singlethreaded ($ccflags et al).
   HOST_NOT_FOUND is typically defined in <netdb.h>.
*/
#if defined(HOST_NOT_FOUND) && !defined(h_errno) && !defined(__CYGWIN__)
extern int h_errno;
#endif

#ifdef HAS_PASSWD
# ifdef I_PWD
#  include <pwd.h>
# else
#  if !defined(VMS)
    struct passwd *getpwnam (char *);
    struct passwd *getpwuid (Uid_t);
#  endif
# endif
# ifdef HAS_GETPWENT
#ifndef getpwent
  struct passwd *getpwent (void);
#elif defined (VMS) && defined (my_getpwent)
  struct passwd *Perl_my_getpwent (void);
#endif
# endif
#endif

#ifdef HAS_GROUP
# ifdef I_GRP
#  include <grp.h>
# else
    struct group *getgrnam (char *);
    struct group *getgrgid (Gid_t);
# endif
# ifdef HAS_GETGRENT
#ifndef getgrent
    struct group *getgrent (void);
#endif
# endif
#endif

#ifdef I_UTIME
#  if defined(_MSC_VER) || defined(__MINGW32__)
#    include <sys/utime.h>
#  else
#    include <utime.h>
#  endif
#endif

#ifdef HAS_CHSIZE
# ifdef my_chsize  /* Probably #defined to Perl_my_chsize in embed.h */
#   undef my_chsize
# endif
# define my_chsize PerlLIO_chsize
#endif

#ifdef HAS_FLOCK
#  define FLOCK flock
#else /* no flock() */

   /* fcntl.h might not have been included, even if it exists, because
      the current Configure only sets I_FCNTL if it's needed to pick up
      the *_OK constants.  Make sure it has been included before testing
      the fcntl() locking constants. */
#  if defined(HAS_FCNTL) && !defined(I_FCNTL)
#    include <fcntl.h>
#  endif

#  if defined(HAS_FCNTL) && defined(FCNTL_CAN_LOCK)
#    define FLOCK fcntl_emulate_flock
#    define FCNTL_EMULATE_FLOCK
#  else /* no flock() or fcntl(F_SETLK,...) */
#    ifdef HAS_LOCKF
#      define FLOCK lockf_emulate_flock
#      define LOCKF_EMULATE_FLOCK
#    endif /* lockf */
#  endif /* no flock() or fcntl(F_SETLK,...) */

#  ifdef FLOCK
     static int FLOCK (int, int);

    /*
     * These are the flock() constants.  Since this sytems doesn't have
     * flock(), the values of the constants are probably not available.
     */
#    ifndef LOCK_SH
#      define LOCK_SH 1
#    endif
#    ifndef LOCK_EX
#      define LOCK_EX 2
#    endif
#    ifndef LOCK_NB
#      define LOCK_NB 4
#    endif
#    ifndef LOCK_UN
#      define LOCK_UN 8
#    endif
#  endif /* emulating flock() */

#endif /* no flock() */

#define ZBTLEN 10
static char zero_but_true[ZBTLEN + 1] = "0 but true";

#if defined(I_SYS_ACCESS) && !defined(R_OK)
#  include <sys/access.h>
#endif

#if defined(HAS_FCNTL) && defined(F_SETFD) && !defined(FD_CLOEXEC)
#  define FD_CLOEXEC 1          /* NeXT needs this */
#endif

#include "reentr.h"

#ifdef __Lynx__
/* Missing protos on LynxOS */
void sethostent(int);
void endhostent(void);
void setnetent(int);
void endnetent(void);
void setprotoent(int);
void endprotoent(void);
void setservent(int);
void endservent(void);
#endif

#undef PERL_EFF_ACCESS_R_OK     /* EFFective uid/gid ACCESS R_OK */
#undef PERL_EFF_ACCESS_W_OK
#undef PERL_EFF_ACCESS_X_OK

/* F_OK unused: if stat() cannot find it... */

#if !defined(PERL_EFF_ACCESS_R_OK) && defined(HAS_ACCESS) && defined(EFF_ONLY_OK) && !defined(NO_EFF_ONLY_OK)
    /* Digital UNIX (when the EFF_ONLY_OK gets fixed), UnixWare */
#   define PERL_EFF_ACCESS_R_OK(p) (access((p), R_OK | EFF_ONLY_OK))
#   define PERL_EFF_ACCESS_W_OK(p) (access((p), W_OK | EFF_ONLY_OK))
#   define PERL_EFF_ACCESS_X_OK(p) (access((p), X_OK | EFF_ONLY_OK))
#endif

#if !defined(PERL_EFF_ACCESS_R_OK) && defined(HAS_EACCESS)
#   ifdef I_SYS_SECURITY
#       include <sys/security.h>
#   endif
#   ifdef ACC_SELF
        /* HP SecureWare */
#       define PERL_EFF_ACCESS_R_OK(p) (eaccess((p), R_OK, ACC_SELF))
#       define PERL_EFF_ACCESS_W_OK(p) (eaccess((p), W_OK, ACC_SELF))
#       define PERL_EFF_ACCESS_X_OK(p) (eaccess((p), X_OK, ACC_SELF))
#   else
        /* SCO */
#       define PERL_EFF_ACCESS_R_OK(p) (eaccess((p), R_OK))
#       define PERL_EFF_ACCESS_W_OK(p) (eaccess((p), W_OK))
#       define PERL_EFF_ACCESS_X_OK(p) (eaccess((p), X_OK))
#   endif
#endif

#if !defined(PERL_EFF_ACCESS_R_OK) && defined(HAS_ACCESSX) && defined(ACC_SELF)
    /* AIX */
#   define PERL_EFF_ACCESS_R_OK(p) (accessx((p), R_OK, ACC_SELF))
#   define PERL_EFF_ACCESS_W_OK(p) (accessx((p), W_OK, ACC_SELF))
#   define PERL_EFF_ACCESS_X_OK(p) (accessx((p), X_OK, ACC_SELF))
#endif

#if !defined(PERL_EFF_ACCESS_R_OK) && defined(HAS_ACCESS)       \
    && (defined(HAS_SETREUID) || defined(HAS_SETRESUID)         \
        || defined(HAS_SETREGID) || defined(HAS_SETRESGID))
/* The Hard Way. */
STATIC int
S_emulate_eaccess(pTHX_ const char* path, Mode_t mode)
{
    Uid_t ruid = getuid();
    Uid_t euid = geteuid();
    Gid_t rgid = getgid();
    Gid_t egid = getegid();
    int res;

    LOCK_CRED_MUTEX;
#if !defined(HAS_SETREUID) && !defined(HAS_SETRESUID)
    Perl_croak(aTHX_ "switching effective uid is not implemented");
#else
#ifdef HAS_SETREUID
    if (setreuid(euid, ruid))
#else
#ifdef HAS_SETRESUID
    if (setresuid(euid, ruid, (Uid_t)-1))
#endif
#endif
        Perl_croak(aTHX_ "entering effective uid failed");
#endif

#if !defined(HAS_SETREGID) && !defined(HAS_SETRESGID)
    Perl_croak(aTHX_ "switching effective gid is not implemented");
#else
#ifdef HAS_SETREGID
    if (setregid(egid, rgid))
#else
#ifdef HAS_SETRESGID
    if (setresgid(egid, rgid, (Gid_t)-1))
#endif
#endif
        Perl_croak(aTHX_ "entering effective gid failed");
#endif

    res = access(path, mode);

#ifdef HAS_SETREUID
    if (setreuid(ruid, euid))
#else
#ifdef HAS_SETRESUID
    if (setresuid(ruid, euid, (Uid_t)-1))
#endif
#endif
        Perl_croak(aTHX_ "leaving effective uid failed");

#ifdef HAS_SETREGID
    if (setregid(rgid, egid))
#else
#ifdef HAS_SETRESGID
    if (setresgid(rgid, egid, (Gid_t)-1))
#endif
#endif
        Perl_croak(aTHX_ "leaving effective gid failed");
    UNLOCK_CRED_MUTEX;

    return res;
}
#   define PERL_EFF_ACCESS_R_OK(p) (emulate_eaccess((p), R_OK))
#   define PERL_EFF_ACCESS_W_OK(p) (emulate_eaccess((p), W_OK))
#   define PERL_EFF_ACCESS_X_OK(p) (emulate_eaccess((p), X_OK))
#endif

#if !defined(PERL_EFF_ACCESS_R_OK)
/* With it or without it: anyway you get a warning: either that
   it is unused, or it is declared static and never defined.
 */
STATIC int
S_emulate_eaccess(pTHX_ const char* path, Mode_t mode)
{
    Perl_croak(aTHX_ "switching effective uid is not implemented");
    /*NOTREACHED*/
    return -1;
}
#endif

PP(pp_backtick)
{
    dSP; dTARGET;
    PerlIO *fp;
    STRLEN n_a;
    char *tmps = POPpx;
    I32 gimme = GIMME_V;
    char *mode = "r";

    TAINT_PROPER("``");
    if (PL_op->op_private & OPpOPEN_IN_RAW)
        mode = "rb";
    else if (PL_op->op_private & OPpOPEN_IN_CRLF)
        mode = "rt";
    fp = PerlProc_popen(tmps, mode);
    if (fp) {
        char *type = NULL;
        if (PL_curcop->cop_io) {
            type = SvPV_nolen(PL_curcop->cop_io);
        }
        if (type && *type)
            PerlIO_apply_layers(aTHX_ fp,mode,type);

        if (gimme == G_VOID) {
            char tmpbuf[256];
            while (PerlIO_read(fp, tmpbuf, sizeof tmpbuf) > 0)
                /*SUPPRESS 530*/
                ;
        }
        else if (gimme == G_SCALAR) {
            ENTER;
            SAVESPTR(PL_rs);
            PL_rs = &PL_sv_undef;
            sv_setpv(TARG, ""); /* note that this preserves previous buffer */
            while (sv_gets(TARG, fp, SvCUR(TARG)) != Nullch)
                /*SUPPRESS 530*/
                ;
            LEAVE;
            XPUSHs(TARG);
            SvTAINTED_on(TARG);
        }
        else {
            SV *sv;

            for (;;) {
                sv = NEWSV(56, 79);
                if (sv_gets(sv, fp, 0) == Nullch) {
                    SvREFCNT_dec(sv);
                    break;
                }
                XPUSHs(sv_2mortal(sv));
                if (SvLEN(sv) - SvCUR(sv) > 20) {
                    SvLEN_set(sv, SvCUR(sv)+1);
                    Renew(SvPVX(sv), SvLEN(sv), char);
                }
                SvTAINTED_on(sv);
            }
        }
        STATUS_NATIVE_SET(PerlProc_pclose(fp));
        TAINT;          /* "I believe that this is not gratuitous!" */
    }
    else {
        STATUS_NATIVE_SET(-1);
        if (gimme == G_SCALAR)
            RETPUSHUNDEF;
    }

    RETURN;
}

PP(pp_glob)
{
    OP *result;
    tryAMAGICunTARGET(iter, -1);

    /* Note that we only ever get here if File::Glob fails to load
     * without at the same time croaking, for some reason, or if
     * perl was built with PERL_EXTERNAL_GLOB */

    ENTER;

#ifndef VMS
    if (PL_tainting) {
        /*
         * The external globbing program may use things we can't control,
         * so for security reasons we must assume the worst.
         */
        TAINT;
        taint_proper(PL_no_security, "glob");
    }
#endif /* !VMS */

    SAVESPTR(PL_last_in_gv);    /* We don't want this to be permanent. */
    PL_last_in_gv = (GV*)*PL_stack_sp--;

    SAVESPTR(PL_rs);            /* This is not permanent, either. */
    PL_rs = sv_2mortal(newSVpvn("\000", 1));
#ifndef DOSISH
#ifndef CSH
    *SvPVX(PL_rs) = '\n';
#endif  /* !CSH */
#endif  /* !DOSISH */

    result = do_readline();
    LEAVE;
    return result;
}

PP(pp_rcatline)
{
    PL_last_in_gv = cGVOP_gv;
    return do_readline();
}

PP(pp_warn)
{
    dSP; dMARK;
    SV *tmpsv;
    char *tmps;
    STRLEN len;
    if (SP - MARK != 1) {
        dTARGET;
        do_join(TARG, &PL_sv_no, MARK, SP);
        tmpsv = TARG;
        SP = MARK + 1;
    }
    else {
        tmpsv = TOPs;
    }
    tmps = SvPV(tmpsv, len);
    if ((!tmps || !len) && PL_errgv) {
        SV *error = ERRSV;
        (void)SvUPGRADE(error, SVt_PV);
        if (SvPOK(error) && SvCUR(error))
            sv_catpv(error, "\t...caught");
        tmpsv = error;
        tmps = SvPV(tmpsv, len);
    }
    if (!tmps || !len)
        tmpsv = sv_2mortal(newSVpvn("Warning: something's wrong", 26));

    Perl_warn(aTHX_ "%"SVf, tmpsv);
    RETSETYES;
}

PP(pp_die)
{
    dSP; dMARK;
    char *tmps;
    SV *tmpsv;
    STRLEN len;
    bool multiarg = 0;
#ifdef VMS
    VMSISH_HUSHED  = VMSISH_HUSHED || (PL_op->op_private & OPpHUSH_VMSISH);
#endif
    if (SP - MARK != 1) {
        dTARGET;
        do_join(TARG, &PL_sv_no, MARK, SP);
        tmpsv = TARG;
        tmps = SvPV(tmpsv, len);
        multiarg = 1;
        SP = MARK + 1;
    }
    else {
        tmpsv = TOPs;
        tmps = SvROK(tmpsv) ? Nullch : SvPV(tmpsv, len);
    }
    if (!tmps || !len) {
        SV *error = ERRSV;
        (void)SvUPGRADE(error, SVt_PV);
        if (multiarg ? SvROK(error) : SvROK(tmpsv)) {
            if (!multiarg)
                SvSetSV(error,tmpsv);
            else if (sv_isobject(error)) {
                HV *stash = SvSTASH(SvRV(error));
                GV *gv = gv_fetchmethod(stash, "PROPAGATE");
                if (gv) {
                    SV *file = sv_2mortal(newSVpv(CopFILE(PL_curcop),0));
                    SV *line = sv_2mortal(newSVuv(CopLINE(PL_curcop)));
                    EXTEND(SP, 3);
                    PUSHMARK(SP);
                    PUSHs(error);
                    PUSHs(file);
                    PUSHs(line);
                    PUTBACK;
                    call_sv((SV*)GvCV(gv),
                            G_SCALAR|G_EVAL|G_KEEPERR);
                    sv_setsv(error,*PL_stack_sp--);
                }
            }
            DIE_NULL;
        }
        else {
            if (SvPOK(error) && SvCUR(error))
                sv_catpv(error, "\t...propagated");
            tmpsv = error;
            tmps = SvPV(tmpsv, len);
        }
    }
    if (!tmps || !len)
        tmpsv = sv_2mortal(newSVpvn("Died", 4));

    DIE(aTHX_ "%"SVf, tmpsv);
}

/* I/O. */

PP(pp_open)
{
    dSP;
    dMARK; dORIGMARK;
    dTARGET;
    GV *gv;
    SV *sv;
    IO *io;
    char *tmps;
    STRLEN len;
    MAGIC *mg;
    bool  ok;

    gv = (GV *)*++MARK;
    if (!isGV(gv))
        DIE(aTHX_ PL_no_usym, "filehandle");
    if ((io = GvIOp(gv)))
        IoFLAGS(GvIOp(gv)) &= ~IOf_UNTAINT;

    if (io && (mg = SvTIED_mg((SV*)io, PERL_MAGIC_tiedscalar))) {
        /* Method's args are same as ours ... */
        /* ... except handle is replaced by the object */
        *MARK-- = SvTIED_obj((SV*)io, mg);
        PUSHMARK(MARK);
        PUTBACK;
        ENTER;
        call_method("OPEN", G_SCALAR);
        LEAVE;
        SPAGAIN;
        RETURN;
    }

    if (MARK < SP) {
        sv = *++MARK;
    }
    else {
        sv = GvSV(gv);
    }

    tmps = SvPV(sv, len);
    ok = do_openn(gv, tmps, len, FALSE, O_RDONLY, 0, Nullfp, MARK+1, (SP-MARK));
    SP = ORIGMARK;
    if (ok)
        PUSHi( (I32)PL_forkprocess );
    else if (PL_forkprocess == 0)               /* we are a new child */
        PUSHi(0);
    else
        RETPUSHUNDEF;
    RETURN;
}

PP(pp_close)
{
    dSP;
    GV *gv;
    IO *io;
    MAGIC *mg;

    if (MAXARG == 0)
        gv = PL_defoutgv;
    else
        gv = (GV*)POPs;

    if (gv && (io = GvIO(gv))
        && (mg = SvTIED_mg((SV*)io, PERL_MAGIC_tiedscalar)))
    {
        PUSHMARK(SP);
        XPUSHs(SvTIED_obj((SV*)io, mg));
        PUTBACK;
        ENTER;
        call_method("CLOSE", G_SCALAR);
        LEAVE;
        SPAGAIN;
        RETURN;
    }
    EXTEND(SP, 1);
    PUSHs(boolSV(do_close(gv, TRUE)));
    RETURN;
}

PP(pp_pipe_op)
{
#ifdef HAS_PIPE
    dSP;
    GV *rgv;
    GV *wgv;
    register IO *rstio;
    register IO *wstio;
    int fd[2];

    wgv = (GV*)POPs;
    rgv = (GV*)POPs;

    if (!rgv || !wgv)
        goto badexit;

    if (SvTYPE(rgv) != SVt_PVGV || SvTYPE(wgv) != SVt_PVGV)
        DIE(aTHX_ PL_no_usym, "filehandle");
    rstio = GvIOn(rgv);
    wstio = GvIOn(wgv);

    if (IoIFP(rstio))
        do_close(rgv, FALSE);
    if (IoIFP(wstio))
        do_close(wgv, FALSE);

    if (PerlProc_pipe(fd) < 0)
        goto badexit;

    IoIFP(rstio) = PerlIO_fdopen(fd[0], "r"PIPE_OPEN_MODE);
    IoOFP(wstio) = PerlIO_fdopen(fd[1], "w"PIPE_OPEN_MODE);
    IoOFP(rstio) = IoIFP(rstio);
    IoIFP(wstio) = IoOFP(wstio);
    IoTYPE(rstio) = IoTYPE_RDONLY;
    IoTYPE(wstio) = IoTYPE_WRONLY;

    if (!IoIFP(rstio) || !IoOFP(wstio)) {
        if (IoIFP(rstio)) PerlIO_close(IoIFP(rstio));
        else PerlLIO_close(fd[0]);
        if (IoOFP(wstio)) PerlIO_close(IoOFP(wstio));
        else PerlLIO_close(fd[1]);
        goto badexit;
    }
#if defined(HAS_FCNTL) && defined(F_SETFD)
    fcntl(fd[0],F_SETFD,fd[0] > PL_maxsysfd);   /* ensure close-on-exec */
    fcntl(fd[1],F_SETFD,fd[1] > PL_maxsysfd);   /* ensure close-on-exec */
#endif
    RETPUSHYES;

badexit:
    RETPUSHUNDEF;
#else
    DIE(aTHX_ PL_no_func, "pipe");
#endif
}

PP(pp_fileno)
{
    dSP; dTARGET;
    GV *gv;
    IO *io;
    PerlIO *fp;
    MAGIC  *mg;

    if (MAXARG < 1)
        RETPUSHUNDEF;
    gv = (GV*)POPs;

    if (gv && (io = GvIO(gv))
        && (mg = SvTIED_mg((SV*)io, PERL_MAGIC_tiedscalar)))
    {
        PUSHMARK(SP);
        XPUSHs(SvTIED_obj((SV*)io, mg));
        PUTBACK;
        ENTER;
        call_method("FILENO", G_SCALAR);
        LEAVE;
        SPAGAIN;
        RETURN;
    }

    if (!gv || !(io = GvIO(gv)) || !(fp = IoIFP(io))) {
        /* Can't do this because people seem to do things like
           defined(fileno($foo)) to check whether $foo is a valid fh.
          if (ckWARN2(WARN_UNOPENED,WARN_CLOSED))
              report_evil_fh(gv, io, PL_op->op_type);
            */
        RETPUSHUNDEF;
    }

    PUSHi(PerlIO_fileno(fp));
    RETURN;
}

PP(pp_umask)
{
    dSP; dTARGET;
#ifdef HAS_UMASK
    Mode_t anum;

    if (MAXARG < 1) {
        anum = PerlLIO_umask(0);
        (void)PerlLIO_umask(anum);
    }
    else
        anum = PerlLIO_umask(POPi);
    TAINT_PROPER("umask");
    XPUSHi(anum);
#else
    /* Only DIE if trying to restrict permissions on `user' (self).
     * Otherwise it's harmless and more useful to just return undef
     * since 'group' and 'other' concepts probably don't exist here. */
    if (MAXARG >= 1 && (POPi & 0700))
        DIE(aTHX_ "umask not implemented");
    XPUSHs(&PL_sv_undef);
#endif
    RETURN;
}

PP(pp_binmode)
{
    dSP;
    GV *gv;
    IO *io;
    PerlIO *fp;
    MAGIC *mg;
    SV *discp = Nullsv;

    if (MAXARG < 1)
        RETPUSHUNDEF;
    if (MAXARG > 1) {
        discp = POPs;
    }

    gv = (GV*)POPs;

    if (gv && (io = GvIO(gv))
        && (mg = SvTIED_mg((SV*)io, PERL_MAGIC_tiedscalar)))
    {
        PUSHMARK(SP);
        XPUSHs(SvTIED_obj((SV*)io, mg));
        if (discp)
            XPUSHs(discp);
        PUTBACK;
        ENTER;
        call_method("BINMODE", G_SCALAR);
        LEAVE;
        SPAGAIN;
        RETURN;
    }

    EXTEND(SP, 1);
    if (!(io = GvIO(gv)) || !(fp = IoIFP(io))) {
        if (ckWARN2(WARN_UNOPENED,WARN_CLOSED))
            report_evil_fh(gv, io, PL_op->op_type);
        SETERRNO(EBADF,RMS_IFI);
        RETPUSHUNDEF;
    }

    PUTBACK;
    if (PerlIO_binmode(aTHX_ fp,IoTYPE(io),mode_from_discipline(discp),
                       (discp) ? SvPV_nolen(discp) : Nullch)) {
        if (IoOFP(io) && IoOFP(io) != IoIFP(io)) {
             if (!PerlIO_binmode(aTHX_ IoOFP(io),IoTYPE(io),
                        mode_from_discipline(discp),
                       (discp) ? SvPV_nolen(discp) : Nullch)) {
                SPAGAIN;
                RETPUSHUNDEF;
             }
        }
        SPAGAIN;
        RETPUSHYES;
    }
    else {
        SPAGAIN;
        RETPUSHUNDEF;
    }
}

PP(pp_tie)
{
    dSP;
    dMARK;
    SV *varsv;
    HV* stash;
    GV *gv;
    SV *sv;
    I32 markoff = MARK - PL_stack_base;
    char *methname;
    int how = PERL_MAGIC_tied;
    U32 items;

    varsv = *++MARK;
    switch(SvTYPE(varsv)) {
        case SVt_PVHV:
            methname = "TIEHASH";
            HvEITER((HV *)varsv) = Null(HE *);
            break;
        case SVt_PVAV:
            methname = "TIEARRAY";
            break;
        case SVt_PVGV:
#ifdef GV_UNIQUE_CHECK
            if (GvUNIQUE((GV*)varsv)) {
                Perl_croak(aTHX_ "Attempt to tie unique GV");
            }
#endif
            methname = "TIEHANDLE";
            how = PERL_MAGIC_tiedscalar;
            /* For tied filehandles, we apply tiedscalar magic to the IO
               slot of the GP rather than the GV itself. AMS 20010812 */
            if (!GvIOp(varsv))
                GvIOp(varsv) = newIO();
            varsv = (SV *)GvIOp(varsv);
            break;
        default:
            methname = "TIESCALAR";
            how = PERL_MAGIC_tiedscalar;
            break;
    }
    items = SP - MARK++;
    if (sv_isobject(*MARK)) {
        ENTER;
        PUSHSTACKi(PERLSI_MAGIC);
        PUSHMARK(SP);
        EXTEND(SP,(I32)items);
        while (items--)
            PUSHs(*MARK++);
        PUTBACK;
        call_method(methname, G_SCALAR);
    }
    else {
        /* Not clear why we don't call call_method here too.
         * perhaps to get different error message ?
         */
        stash = gv_stashsv(*MARK, FALSE);
        if (!stash || !(gv = gv_fetchmethod(stash, methname))) {
            DIE(aTHX_ "Can't locate object method \"%s\" via package \"%"SVf"\"",
                 methname, *MARK);
        }
        ENTER;
        PUSHSTACKi(PERLSI_MAGIC);
        PUSHMARK(SP);
        EXTEND(SP,(I32)items);
        while (items--)
            PUSHs(*MARK++);
        PUTBACK;
        call_sv((SV*)GvCV(gv), G_SCALAR);
    }
    SPAGAIN;

    sv = TOPs;
    POPSTACK;
    if (sv_isobject(sv)) {
        sv_unmagic(varsv, how);
        /* Croak if a self-tie on an aggregate is attempted. */
        if (varsv == SvRV(sv) &&
            (SvTYPE(varsv) == SVt_PVAV ||
             SvTYPE(varsv) == SVt_PVHV))
            Perl_croak(aTHX_
                       "Self-ties of arrays and hashes are not supported");
        sv_magic(varsv, (SvRV(sv) == varsv ? Nullsv : sv), how, Nullch, 0);
    }
    LEAVE;
    SP = PL_stack_base + markoff;
    PUSHs(sv);
    RETURN;
}

PP(pp_untie)
{
    dSP;
    MAGIC *mg;
    SV *sv = POPs;
    char how = (SvTYPE(sv) == SVt_PVHV || SvTYPE(sv) == SVt_PVAV)
                ? PERL_MAGIC_tied : PERL_MAGIC_tiedscalar;

    if (SvTYPE(sv) == SVt_PVGV && !(sv = (SV *)GvIOp(sv)))
        RETPUSHYES;

    if ((mg = SvTIED_mg(sv, how))) {
        SV *obj = SvRV(SvTIED_obj(sv, mg));
        GV *gv;
        CV *cv = NULL;
        if (obj) {
            if ((gv = gv_fetchmethod_autoload(SvSTASH(obj), "UNTIE", FALSE)) &&
               isGV(gv) && (cv = GvCV(gv))) {
               PUSHMARK(SP);
               XPUSHs(SvTIED_obj((SV*)gv, mg));
               XPUSHs(sv_2mortal(newSViv(SvREFCNT(obj)-1)));
               PUTBACK;
               ENTER;
               call_sv((SV *)cv, G_VOID);
               LEAVE;
               SPAGAIN;
            }
           else if (ckWARN(WARN_UNTIE)) {
               if (mg && SvREFCNT(obj) > 1)
                  Perl_warner(aTHX_ packWARN(WARN_UNTIE),
                      "untie attempted while %"UVuf" inner references still exist",
                       (UV)SvREFCNT(obj) - 1 ) ;
           }
        }
    }
    sv_unmagic(sv, how) ;
    RETPUSHYES;
}

PP(pp_tied)
{
    dSP;
    MAGIC *mg;
    SV *sv = POPs;
    char how = (SvTYPE(sv) == SVt_PVHV || SvTYPE(sv) == SVt_PVAV)
                ? PERL_MAGIC_tied : PERL_MAGIC_tiedscalar;

    if (SvTYPE(sv) == SVt_PVGV && !(sv = (SV *)GvIOp(sv)))
        RETPUSHUNDEF;

    if ((mg = SvTIED_mg(sv, how))) {
        SV *osv = SvTIED_obj(sv, mg);
        if (osv == mg->mg_obj)
            osv = sv_mortalcopy(osv);
        PUSHs(osv);
        RETURN;
    }
    RETPUSHUNDEF;
}

PP(pp_dbmopen)
{
    dSP;
    HV *hv;
    dPOPPOPssrl;
    HV* stash;
    GV *gv;
    SV *sv;

    hv = (HV*)POPs;

    sv = sv_mortalcopy(&PL_sv_no);
    sv_setpv(sv, "AnyDBM_File");
    stash = gv_stashsv(sv, FALSE);
    if (!stash || !(gv = gv_fetchmethod(stash, "TIEHASH"))) {
        PUTBACK;
        require_pv("AnyDBM_File.pm");
        SPAGAIN;
        if (!(gv = gv_fetchmethod(stash, "TIEHASH")))
            DIE(aTHX_ "No dbm on this machine");
    }

    ENTER;
    PUSHMARK(SP);

    EXTEND(SP, 5);
    PUSHs(sv);
    PUSHs(left);
    if (SvIV(right))
        PUSHs(sv_2mortal(newSVuv(O_RDWR|O_CREAT)));
    else
        PUSHs(sv_2mortal(newSVuv(O_RDWR)));
    PUSHs(right);
    PUTBACK;
    call_sv((SV*)GvCV(gv), G_SCALAR);
    SPAGAIN;

    if (!sv_isobject(TOPs)) {
        SP--;
        PUSHMARK(SP);
        PUSHs(sv);
        PUSHs(left);
        PUSHs(sv_2mortal(newSVuv(O_RDONLY)));
        PUSHs(right);
        PUTBACK;
        call_sv((SV*)GvCV(gv), G_SCALAR);
        SPAGAIN;
    }

    if (sv_isobject(TOPs)) {
        sv_unmagic((SV *) hv, PERL_MAGIC_tied);
        sv_magic((SV*)hv, TOPs, PERL_MAGIC_tied, Nullch, 0);
    }
    LEAVE;
    RETURN;
}

PP(pp_dbmclose)
{
    return pp_untie();
}

PP(pp_sselect)
{
#ifdef HAS_SELECT
    dSP; dTARGET;
    register I32 i;
    register I32 j;
    register char *s;
    register SV *sv;
    NV value;
    I32 maxlen = 0;
    I32 nfound;
    struct timeval timebuf;
    struct timeval *tbuf = &timebuf;
    I32 growsize;
    char *fd_sets[4];
    STRLEN n_a;
#if BYTEORDER != 0x1234 && BYTEORDER != 0x12345678
        I32 masksize;
        I32 offset;
        I32 k;

#   if BYTEORDER & 0xf0000
#       define ORDERBYTE (0x88888888 - BYTEORDER)
#   else
#       define ORDERBYTE (0x4444 - BYTEORDER)
#   endif

#endif

    SP -= 4;
    for (i = 1; i <= 3; i++) {
        if (!SvPOK(SP[i]))
            continue;
        j = SvCUR(SP[i]);
        if (maxlen < j)
            maxlen = j;
    }

/* little endians can use vecs directly */
#if BYTEORDER != 0x1234 && BYTEORDER != 0x12345678
#  ifdef NFDBITS

#    ifndef NBBY
#     define NBBY 8
#    endif

    masksize = NFDBITS / NBBY;
#  else
    masksize = sizeof(long);    /* documented int, everyone seems to use long */
#  endif
    Zero(&fd_sets[0], 4, char*);
#endif

#  if SELECT_MIN_BITS == 1
    growsize = sizeof(fd_set);
#  else
#   if defined(__GLIBC__) && defined(__FD_SETSIZE)
#      undef SELECT_MIN_BITS
#      define SELECT_MIN_BITS __FD_SETSIZE
#   endif
    /* If SELECT_MIN_BITS is greater than one we most probably will want
     * to align the sizes with SELECT_MIN_BITS/8 because for example
     * in many little-endian (Intel, Alpha) systems (Linux, OS/2, Digital
     * UNIX, Solaris, NeXT, Darwin) the smallest quantum select() operates
     * on (sets/tests/clears bits) is 32 bits.  */
    growsize = maxlen + (SELECT_MIN_BITS/8 - (maxlen % (SELECT_MIN_BITS/8)));
#  endif

    sv = SP[4];
    if (SvOK(sv)) {
        value = SvNV(sv);
        if (value < 0.0)
            value = 0.0;
        timebuf.tv_sec = (long)value;
        value -= (NV)timebuf.tv_sec;
        timebuf.tv_usec = (long)(value * 1000000.0);
    }
    else
        tbuf = Null(struct timeval*);

    for (i = 1; i <= 3; i++) {
        sv = SP[i];
        if (!SvOK(sv)) {
            fd_sets[i] = 0;
            continue;
        }
        else if (!SvPOK(sv))
            SvPV_force(sv,n_a); /* force string conversion */
        j = SvLEN(sv);
        if (j < growsize) {
            Sv_Grow(sv, growsize);
        }
        j = SvCUR(sv);
        s = SvPVX(sv) + j;
        while (++j <= growsize) {
            *s++ = '\0';
        }

#if BYTEORDER != 0x1234 && BYTEORDER != 0x12345678
        s = SvPVX(sv);
        New(403, fd_sets[i], growsize, char);
        for (offset = 0; offset < growsize; offset += masksize) {
            for (j = 0, k=ORDERBYTE; j < masksize; j++, (k >>= 4))
                fd_sets[i][j+offset] = s[(k % masksize) + offset];
        }
#else
        fd_sets[i] = SvPVX(sv);
#endif
    }

#ifdef PERL_IRIX5_SELECT_TIMEVAL_VOID_CAST
    /* Can't make just the (void*) conditional because that would be
     * cpp #if within cpp macro, and not all compilers like that. */
    nfound = PerlSock_select(
        maxlen * 8,
        (Select_fd_set_t) fd_sets[1],
        (Select_fd_set_t) fd_sets[2],
        (Select_fd_set_t) fd_sets[3],
        (void*) tbuf); /* Workaround for compiler bug. */
#else
    nfound = PerlSock_select(
        maxlen * 8,
        (Select_fd_set_t) fd_sets[1],
        (Select_fd_set_t) fd_sets[2],
        (Select_fd_set_t) fd_sets[3],
        tbuf);
#endif
    for (i = 1; i <= 3; i++) {
        if (fd_sets[i]) {
            sv = SP[i];
#if BYTEORDER != 0x1234 && BYTEORDER != 0x12345678
            s = SvPVX(sv);
            for (offset = 0; offset < growsize; offset += masksize) {
                for (j = 0, k=ORDERBYTE; j < masksize; j++, (k >>= 4))
                    s[(k % masksize) + offset] = fd_sets[i][j+offset];
            }
            Safefree(fd_sets[i]);
#endif
            SvSETMAGIC(sv);
        }
    }

    PUSHi(nfound);
    if (GIMME == G_ARRAY && tbuf) {
        value = (NV)(timebuf.tv_sec) +
                (NV)(timebuf.tv_usec) / 1000000.0;
        PUSHs(sv = sv_mortalcopy(&PL_sv_no));
        sv_setnv(sv, value);
    }
    RETURN;
#else
    DIE(aTHX_ "select not implemented");
#endif
}

void
Perl_setdefout(pTHX_ GV *gv)
{
    if (gv)
        (void)SvREFCNT_inc(gv);
    if (PL_defoutgv)
        SvREFCNT_dec(PL_defoutgv);
    PL_defoutgv = gv;
}

PP(pp_select)
{
    dSP; dTARGET;
    GV *newdefout, *egv;
    HV *hv;

    newdefout = (PL_op->op_private > 0) ? ((GV *) POPs) : (GV *) NULL;

    egv = GvEGV(PL_defoutgv);
    if (!egv)
        egv = PL_defoutgv;
    hv = GvSTASH(egv);
    if (! hv)
        XPUSHs(&PL_sv_undef);
    else {
        GV **gvp = (GV**)hv_fetch(hv, GvNAME(egv), GvNAMELEN(egv), FALSE);
        if (gvp && *gvp == egv) {
            gv_efullname4(TARG, PL_defoutgv, Nullch, TRUE);
            XPUSHTARG;
        }
        else {
            XPUSHs(sv_2mortal(newRV((SV*)egv)));
        }
    }

    if (newdefout) {
        if (!GvIO(newdefout))
            gv_IOadd(newdefout);
        setdefout(newdefout);
    }

    RETURN;
}

PP(pp_getc)
{
    dSP; dTARGET;
    GV *gv;
    IO *io = NULL;
    MAGIC *mg;

    if (MAXARG == 0)
        gv = PL_stdingv;
    else
        gv = (GV*)POPs;

    if (gv && (io = GvIO(gv))
        && (mg = SvTIED_mg((SV*)io, PERL_MAGIC_tiedscalar)))
    {
        I32 gimme = GIMME_V;
        PUSHMARK(SP);
        XPUSHs(SvTIED_obj((SV*)io, mg));
        PUTBACK;
        ENTER;
        call_method("GETC", gimme);
        LEAVE;
        SPAGAIN;
        if (gimme == G_SCALAR)
            SvSetMagicSV_nosteal(TARG, TOPs);
        RETURN;
    }
    if (!gv || do_eof(gv)) { /* make sure we have fp with something */
        if (ckWARN2(WARN_UNOPENED,WARN_CLOSED)
                && (!io || (!IoIFP(io) && IoTYPE(io) != IoTYPE_WRONLY)))
            report_evil_fh(gv, io, PL_op->op_type);
        SETERRNO(EBADF,RMS_IFI);
        RETPUSHUNDEF;
    }
    TAINT;
    sv_setpv(TARG, " ");
    *SvPVX(TARG) = PerlIO_getc(IoIFP(GvIOp(gv))); /* should never be EOF */
    if (PerlIO_isutf8(IoIFP(GvIOp(gv)))) {
        /* Find out how many bytes the char needs */
        Size_t len = UTF8SKIP(SvPVX(TARG));
        if (len > 1) {
            SvGROW(TARG,len+1);
            len = PerlIO_read(IoIFP(GvIOp(gv)),SvPVX(TARG)+1,len-1);
            SvCUR_set(TARG,1+len);
        }
        SvUTF8_on(TARG);
    }
    PUSHTARG;
    RETURN;
}

PP(pp_read)
{
    return pp_sysread();
}

STATIC OP *
S_doform(pTHX_ CV *cv, GV *gv, OP *retop)
{
    register PERL_CONTEXT *cx;
    I32 gimme = GIMME_V;

    ENTER;
    SAVETMPS;

    push_return(retop);
    PUSHBLOCK(cx, CXt_FORMAT, PL_stack_sp);
    PUSHFORMAT(cx);
    PAD_SET_CUR(CvPADLIST(cv), 1);

    setdefout(gv);          /* locally select filehandle so $% et al work */
    return CvSTART(cv);
}

PP(pp_enterwrite)
{
    dSP;
    register GV *gv;
    register IO *io;
    GV *fgv;
    CV *cv;

    if (MAXARG == 0)
        gv = PL_defoutgv;
    else {
        gv = (GV*)POPs;
        if (!gv)
            gv = PL_defoutgv;
    }
    EXTEND(SP, 1);
    io = GvIO(gv);
    if (!io) {
        RETPUSHNO;
    }
    if (IoFMT_GV(io))
        fgv = IoFMT_GV(io);
    else
        fgv = gv;

    cv = GvFORM(fgv);
    if (!cv) {
        char *name = NULL;
        if (fgv) {
            SV *tmpsv = sv_newmortal();
            gv_efullname4(tmpsv, fgv, Nullch, FALSE);
            name = SvPV_nolen(tmpsv);
        }
        if (name && *name)
            DIE(aTHX_ "Undefined format \"%s\" called", name);
        DIE(aTHX_ "Not a format reference");
    }
    if (CvCLONE(cv))
        cv = (CV*)sv_2mortal((SV*)cv_clone(cv));

    IoFLAGS(io) &= ~IOf_DIDTOP;
    return doform(cv,gv,PL_op->op_next);
}

PP(pp_leavewrite)
{
    dSP;
    GV *gv = cxstack[cxstack_ix].blk_sub.gv;
    register IO *io = GvIOp(gv);
    PerlIO *ofp = IoOFP(io);
    PerlIO *fp;
    SV **newsp;
    I32 gimme;
    register PERL_CONTEXT *cx;

    DEBUG_f(PerlIO_printf(Perl_debug_log, "left=%ld, todo=%ld\n",
          (long)IoLINES_LEFT(io), (long)FmLINES(PL_formtarget)));
    if (!io || !ofp)
        goto forget_top;
    if (IoLINES_LEFT(io) < FmLINES(PL_formtarget) &&
        PL_formtarget != PL_toptarget)
    {
        GV *fgv;
        CV *cv;
        if (!IoTOP_GV(io)) {
            GV *topgv;
            SV *topname;

            if (!IoTOP_NAME(io)) {
                if (!IoFMT_NAME(io))
                    IoFMT_NAME(io) = savepv(GvNAME(gv));
                topname = sv_2mortal(Perl_newSVpvf(aTHX_ "%s_TOP", GvNAME(gv)));
                topgv = gv_fetchpv(SvPVX(topname), FALSE, SVt_PVFM);
                if ((topgv && GvFORM(topgv)) ||
                  !gv_fetchpv("top",FALSE,SVt_PVFM))
                    IoTOP_NAME(io) = savesvpv(topname);
                else
                    IoTOP_NAME(io) = savepv("top");
            }
            topgv = gv_fetchpv(IoTOP_NAME(io),FALSE, SVt_PVFM);
            if (!topgv || !GvFORM(topgv)) {
                IoLINES_LEFT(io) = IoPAGE_LEN(io);
                goto forget_top;
            }
            IoTOP_GV(io) = topgv;
        }
        if (IoFLAGS(io) & IOf_DIDTOP) { /* Oh dear.  It still doesn't fit. */
            I32 lines = IoLINES_LEFT(io);
            char *s = SvPVX(PL_formtarget);
            if (lines <= 0)             /* Yow, header didn't even fit!!! */
                goto forget_top;
            while (lines-- > 0) {
                s = strchr(s, '\n');
                if (!s)
                    break;
                s++;
            }
            if (s) {
                STRLEN save = SvCUR(PL_formtarget);
                SvCUR_set(PL_formtarget, s - SvPVX(PL_formtarget));
                do_print(PL_formtarget, ofp);
                SvCUR_set(PL_formtarget, save);
                sv_chop(PL_formtarget, s);
                FmLINES(PL_formtarget) -= IoLINES_LEFT(io);
            }
        }
        if (IoLINES_LEFT(io) >= 0 && IoPAGE(io) > 0)
            do_print(PL_formfeed, ofp);
        IoLINES_LEFT(io) = IoPAGE_LEN(io);
        IoPAGE(io)++;
        PL_formtarget = PL_toptarget;
        IoFLAGS(io) |= IOf_DIDTOP;
        fgv = IoTOP_GV(io);
        if (!fgv)
            DIE(aTHX_ "bad top format reference");
        cv = GvFORM(fgv);
        {
            char *name = NULL;
            if (!cv) {
                SV *sv = sv_newmortal();
                gv_efullname4(sv, fgv, Nullch, FALSE);
                name = SvPV_nolen(sv);
            }
            if (name && *name)
                DIE(aTHX_ "Undefined top format \"%s\" called",name);
            /* why no:
            else
                DIE(aTHX_ "Undefined top format called");
            ?*/
        }
        if (CvCLONE(cv))
            cv = (CV*)sv_2mortal((SV*)cv_clone(cv));
        return doform(cv,gv,PL_op);
    }

  forget_top:
    POPBLOCK(cx,PL_curpm);
    POPFORMAT(cx);
    LEAVE;

    fp = IoOFP(io);
    if (!fp) {
        if (ckWARN2(WARN_CLOSED,WARN_IO)) {
            if (IoIFP(io))
                report_evil_fh(gv, io, OP_phoney_INPUT_ONLY);
            else if (ckWARN(WARN_CLOSED))
                report_evil_fh(gv, io, PL_op->op_type);
        }
        PUSHs(&PL_sv_no);
    }
    else {
        if ((IoLINES_LEFT(io) -= FmLINES(PL_formtarget)) < 0) {
            if (ckWARN(WARN_IO))
                Perl_warner(aTHX_ packWARN(WARN_IO), "page overflow");
        }
        if (!do_print(PL_formtarget, fp))
            PUSHs(&PL_sv_no);
        else {
            FmLINES(PL_formtarget) = 0;
            SvCUR_set(PL_formtarget, 0);
            *SvEND(PL_formtarget) = '\0';
            if (IoFLAGS(io) & IOf_FLUSH)
                (void)PerlIO_flush(fp);
            PUSHs(&PL_sv_yes);
        }
    }
    /* bad_ofp: */
    PL_formtarget = PL_bodytarget;
    PUTBACK;
    return pop_return();
}

PP(pp_prtf)
{
    dSP; dMARK; dORIGMARK;
    GV *gv;
    IO *io;
    PerlIO *fp;
    SV *sv;
    MAGIC *mg;

    if (PL_op->op_flags & OPf_STACKED)
        gv = (GV*)*++MARK;
    else
        gv = PL_defoutgv;

    if (gv && (io = GvIO(gv))
        && (mg = SvTIED_mg((SV*)io, PERL_MAGIC_tiedscalar)))
    {
        if (MARK == ORIGMARK) {
            MEXTEND(SP, 1);
            ++MARK;
            Move(MARK, MARK + 1, (SP - MARK) + 1, SV*);
            ++SP;
        }
        PUSHMARK(MARK - 1);
        *MARK = SvTIED_obj((SV*)io, mg);
        PUTBACK;
        ENTER;
        call_method("PRINTF", G_SCALAR);
        LEAVE;
        SPAGAIN;
        MARK = ORIGMARK + 1;
        *MARK = *SP;
        SP = MARK;
        RETURN;
    }

    sv = NEWSV(0,0);
    if (!(io = GvIO(gv))) {
        if (ckWARN2(WARN_UNOPENED,WARN_CLOSED))
            report_evil_fh(gv, io, PL_op->op_type);
        SETERRNO(EBADF,RMS_IFI);
        goto just_say_no;
    }
    else if (!(fp = IoOFP(io))) {
        if (ckWARN2(WARN_CLOSED,WARN_IO))  {
            if (IoIFP(io))
                report_evil_fh(gv, io, OP_phoney_INPUT_ONLY);
            else if (ckWARN(WARN_CLOSED))
                report_evil_fh(gv, io, PL_op->op_type);
        }
        SETERRNO(EBADF,IoIFP(io)?RMS_FAC:RMS_IFI);
        goto just_say_no;
    }
    else {
        do_sprintf(sv, SP - MARK, MARK + 1);
        if (!do_print(sv, fp))
            goto just_say_no;

        if (IoFLAGS(io) & IOf_FLUSH)
            if (PerlIO_flush(fp) == EOF)
                goto just_say_no;
    }
    SvREFCNT_dec(sv);
    SP = ORIGMARK;
    PUSHs(&PL_sv_yes);
    RETURN;

  just_say_no:
    SvREFCNT_dec(sv);
    SP = ORIGMARK;
    PUSHs(&PL_sv_undef);
    RETURN;
}

PP(pp_sysopen)
{
    dSP;
    GV *gv;
    SV *sv;
    char *tmps;
    STRLEN len;
    int mode, perm;

    if (MAXARG > 3)
        perm = POPi;
    else
        perm = 0666;
    mode = POPi;
    sv = POPs;
    gv = (GV *)POPs;

    /* Need TIEHANDLE method ? */

    tmps = SvPV(sv, len);
    if (do_open(gv, tmps, len, TRUE, mode, perm, Nullfp)) {
        IoLINES(GvIOp(gv)) = 0;
        PUSHs(&PL_sv_yes);
    }
    else {
        PUSHs(&PL_sv_undef);
    }
    RETURN;
}

PP(pp_sysread)
{
    dSP; dMARK; dORIGMARK; dTARGET;
    int offset;
    GV *gv;
    IO *io;
    char *buffer;
    SSize_t length;
    SSize_t count;
    Sock_size_t bufsize;
    SV *bufsv;
    STRLEN blen;
    MAGIC *mg;
    int fp_utf8;
    int buffer_utf8;
    SV *read_target;
    Size_t got = 0;
    Size_t wanted;
    bool charstart = FALSE;
    STRLEN charskip = 0;
    STRLEN skip = 0;

    gv = (GV*)*++MARK;
    if ((PL_op->op_type == OP_READ || PL_op->op_type == OP_SYSREAD)
        && gv && (io = GvIO(gv))
        && (mg = SvTIED_mg((SV*)io, PERL_MAGIC_tiedscalar)))
    {
        SV *sv;
        
        PUSHMARK(MARK-1);
        *MARK = SvTIED_obj((SV*)io, mg);
        ENTER;
        call_method("READ", G_SCALAR);
        LEAVE;
        SPAGAIN;
        sv = POPs;
        SP = ORIGMARK;
        PUSHs(sv);
        RETURN;
    }

    if (!gv)
        goto say_undef;
    bufsv = *++MARK;
    if (! SvOK(bufsv))
        sv_setpvn(bufsv, "", 0);
    length = SvIVx(*++MARK);
    SETERRNO(0,0);
    if (MARK < SP)
        offset = SvIVx(*++MARK);
    else
        offset = 0;
    io = GvIO(gv);
    if (!io || !IoIFP(io)) {
        if (ckWARN2(WARN_UNOPENED,WARN_CLOSED))
            report_evil_fh(gv, io, PL_op->op_type);
        SETERRNO(EBADF,RMS_IFI);
        goto say_undef;
    }
    if ((fp_utf8 = PerlIO_isutf8(IoIFP(io))) && !IN_BYTES) {
        buffer = SvPVutf8_force(bufsv, blen);
        /* UTF-8 may not have been set if they are all low bytes */
        SvUTF8_on(bufsv);
        buffer_utf8 = 0;
    }
    else {
        buffer = SvPV_force(bufsv, blen);
        buffer_utf8 = !IN_BYTES && SvUTF8(bufsv);
    }
    if (length < 0)
        DIE(aTHX_ "Negative length");
    wanted = length;

    charstart = TRUE;
    charskip  = 0;
    skip = 0;

#ifdef HAS_SOCKET
    if (PL_op->op_type == OP_RECV) {
        char namebuf[MAXPATHLEN];
#if (defined(VMS_DO_SOCKETS) && defined(DECCRTL_SOCKETS)) || defined(MPE) || defined(__QNXNTO__)
        bufsize = sizeof (struct sockaddr_in);
#else
        bufsize = sizeof namebuf;
#endif
#ifdef OS2      /* At least Warp3+IAK: only the first byte of bufsize set */
        if (bufsize >= 256)
            bufsize = 255;
#endif
        buffer = SvGROW(bufsv, (STRLEN)(length+1));
        /* 'offset' means 'flags' here */
        count = PerlSock_recvfrom(PerlIO_fileno(IoIFP(io)), buffer, length, offset,
                          (struct sockaddr *)namebuf, &bufsize);
        if (count < 0)
            RETPUSHUNDEF;
#ifdef EPOC
        /* Bogus return without padding */
        bufsize = sizeof (struct sockaddr_in);
#endif
        SvCUR_set(bufsv, count);
        *SvEND(bufsv) = '\0';
        (void)SvPOK_only(bufsv);
        if (fp_utf8)
            SvUTF8_on(bufsv);
        SvSETMAGIC(bufsv);
        /* This should not be marked tainted if the fp is marked clean */
        if (!(IoFLAGS(io) & IOf_UNTAINT))
            SvTAINTED_on(bufsv);
        SP = ORIGMARK;
        sv_setpvn(TARG, namebuf, bufsize);
        PUSHs(TARG);
        RETURN;
    }
#else
    if (PL_op->op_type == OP_RECV)
        DIE(aTHX_ PL_no_sock_func, "recv");
#endif
    if (DO_UTF8(bufsv)) {
        /* offset adjust in characters not bytes */
        blen = sv_len_utf8(bufsv);
    }
    if (offset < 0) {
        if (-offset > (int)blen)
            DIE(aTHX_ "Offset outside string");
        offset += blen;
    }
    if (DO_UTF8(bufsv)) {
        /* convert offset-as-chars to offset-as-bytes */
        if (offset >= (int)blen)
            offset += SvCUR(bufsv) - blen;
        else
            offset = utf8_hop((U8 *)buffer,offset) - (U8 *) buffer;
    }
 more_bytes:
    bufsize = SvCUR(bufsv);
    /* Allocating length + offset + 1 isn't perfect in the case of reading
       bytes from a byte file handle into a UTF8 buffer, but it won't harm us
       unduly.
       (should be 2 * length + offset + 1, or possibly something longer if
       PL_encoding is true) */
    buffer  = SvGROW(bufsv, (STRLEN)(length+offset+1));
    if (offset > bufsize) { /* Zero any newly allocated space */
        Zero(buffer+bufsize, offset-bufsize, char);
    }
    buffer = buffer + offset;
    if (!buffer_utf8) {
        read_target = bufsv;
    } else {
        /* Best to read the bytes into a new SV, upgrade that to UTF8, then
           concatenate it to the current buffer.  */

        /* Truncate the existing buffer to the start of where we will be
           reading to:  */
        SvCUR_set(bufsv, offset);

        read_target = sv_newmortal();
        (void)SvUPGRADE(read_target, SVt_PV);
        buffer = SvGROW(read_target, (STRLEN)(length + 1));
    }

    if (PL_op->op_type == OP_SYSREAD) {
#ifdef PERL_SOCK_SYSREAD_IS_RECV
        if (IoTYPE(io) == IoTYPE_SOCKET) {
            count = PerlSock_recv(PerlIO_fileno(IoIFP(io)),
                                   buffer, length, 0);
        }
        else
#endif
        {
            count = PerlLIO_read(PerlIO_fileno(IoIFP(io)),
                                  buffer, length);
        }
    }
    else
#ifdef HAS_SOCKET__bad_code_maybe
    if (IoTYPE(io) == IoTYPE_SOCKET) {
        char namebuf[MAXPATHLEN];
#if defined(VMS_DO_SOCKETS) && defined(DECCRTL_SOCKETS)
        bufsize = sizeof (struct sockaddr_in);
#else
        bufsize = sizeof namebuf;
#endif
        count = PerlSock_recvfrom(PerlIO_fileno(IoIFP(io)), buffer, length, 0,
                          (struct sockaddr *)namebuf, &bufsize);
    }
    else
#endif
    {
        count = PerlIO_read(IoIFP(io), buffer, length);
        /* PerlIO_read() - like fread() returns 0 on both error and EOF */
        if (count == 0 && PerlIO_error(IoIFP(io)))
            count = -1;
    }
    if (count < 0) {
        if ((IoTYPE(io) == IoTYPE_WRONLY) && ckWARN(WARN_IO))
                report_evil_fh(gv, io, OP_phoney_OUTPUT_ONLY);
        goto say_undef;
    }
    SvCUR_set(read_target, count+(buffer - SvPVX(read_target)));
    *SvEND(read_target) = '\0';
    (void)SvPOK_only(read_target);
    if (fp_utf8 && !IN_BYTES) {
        /* Look at utf8 we got back and count the characters */
        char *bend = buffer + count;
        while (buffer < bend) {
            if (charstart) {
                skip = UTF8SKIP(buffer);
                charskip = 0;
            }
            if (buffer - charskip + skip > bend) {
                /* partial character - try for rest of it */
                length = skip - (bend-buffer);
                offset = bend - SvPVX(bufsv);
                charstart = FALSE;
                charskip += count;
                goto more_bytes;
            }
            else {
                got++;
                buffer += skip;
                charstart = TRUE;
                charskip  = 0;
            }
        }
        /* If we have not 'got' the number of _characters_ we 'wanted' get some more
           provided amount read (count) was what was requested (length)
         */
        if (got < wanted && count == length) {
            length = wanted - got;
            offset = bend - SvPVX(bufsv);
            goto more_bytes;
        }
        /* return value is character count */
        count = got;
        SvUTF8_on(bufsv);
    }
    else if (buffer_utf8) {
        /* Let svcatsv upgrade the bytes we read in to utf8.
           The buffer is a mortal so will be freed soon.  */
        sv_catsv_nomg(bufsv, read_target);
    }
    SvSETMAGIC(bufsv);
    /* This should not be marked tainted if the fp is marked clean */
    if (!(IoFLAGS(io) & IOf_UNTAINT))
        SvTAINTED_on(bufsv);
    SP = ORIGMARK;
    PUSHi(count);
    RETURN;

  say_undef:
    SP = ORIGMARK;
    RETPUSHUNDEF;
}

PP(pp_syswrite)
{
    dSP;
    int items = (SP - PL_stack_base) - TOPMARK;
    if (items == 2) {
        SV *sv;
        EXTEND(SP, 1);
        sv = sv_2mortal(newSViv(sv_len(*SP)));
        PUSHs(sv);
        PUTBACK;
    }
    return pp_send();
}

PP(pp_send)
{
    dSP; dMARK; dORIGMARK; dTARGET;
    GV *gv;
    IO *io;
    SV *bufsv;
    char *buffer;
    Size_t length;
    SSize_t retval;
    STRLEN blen;
    MAGIC *mg;

    gv = (GV*)*++MARK;
    if (PL_op->op_type == OP_SYSWRITE
        && gv && (io = GvIO(gv))
        && (mg = SvTIED_mg((SV*)io, PERL_MAGIC_tiedscalar)))
    {
        SV *sv;
        
        PUSHMARK(MARK-1);
        *MARK = SvTIED_obj((SV*)io, mg);
        ENTER;
        call_method("WRITE", G_SCALAR);
        LEAVE;
        SPAGAIN;
        sv = POPs;
        SP = ORIGMARK;
        PUSHs(sv);
        RETURN;
    }
    if (!gv)
        goto say_undef;
    bufsv = *++MARK;
#if Size_t_size > IVSIZE
    length = (Size_t)SvNVx(*++MARK);
#else
    length = (Size_t)SvIVx(*++MARK);
#endif
    if ((SSize_t)length < 0)
        DIE(aTHX_ "Negative length");
    SETERRNO(0,0);
    io = GvIO(gv);
    if (!io || !IoIFP(io)) {
        retval = -1;
        if (ckWARN(WARN_CLOSED))
            report_evil_fh(gv, io, PL_op->op_type);
        SETERRNO(EBADF,RMS_IFI);
        goto say_undef;
    }

    if (PerlIO_isutf8(IoIFP(io))) {
        if (!SvUTF8(bufsv)) {
            bufsv = sv_2mortal(newSVsv(bufsv));
            buffer = sv_2pvutf8(bufsv, &blen);
        } else
            buffer = SvPV(bufsv, blen);
    }
    else {
         if (DO_UTF8(bufsv)) {
              /* Not modifying source SV, so making a temporary copy. */
              bufsv = sv_2mortal(newSVsv(bufsv));
              sv_utf8_downgrade(bufsv, FALSE);
         }
         buffer = SvPV(bufsv, blen);
    }

    if (PL_op->op_type == OP_SYSWRITE) {
        IV offset;
        if (DO_UTF8(bufsv)) {
            /* length and offset are in chars */
            blen   = sv_len_utf8(bufsv);
        }
        if (MARK < SP) {
            offset = SvIVx(*++MARK);
            if (offset < 0) {
                if (-offset > (IV)blen)
                    DIE(aTHX_ "Offset outside string");
                offset += blen;
            } else if (offset >= (IV)blen && blen > 0)
                DIE(aTHX_ "Offset outside string");
        } else
            offset = 0;
        if (length > blen - offset)
            length = blen - offset;
        if (DO_UTF8(bufsv)) {
            buffer = (char*)utf8_hop((U8 *)buffer, offset);
            length = utf8_hop((U8 *)buffer, length) - (U8 *)buffer;
        }
        else {
            buffer = buffer+offset;
        }
#ifdef PERL_SOCK_SYSWRITE_IS_SEND
        if (IoTYPE(io) == IoTYPE_SOCKET) {
            retval = PerlSock_send(PerlIO_fileno(IoIFP(io)),
                                   buffer, length, 0);
        }
        else
#endif
        {
            /* See the note at doio.c:do_print about filesize limits. --jhi */
            retval = PerlLIO_write(PerlIO_fileno(IoIFP(io)),
                                   buffer, length);
        }
    }
#ifdef HAS_SOCKET
    else if (SP > MARK) {
        char *sockbuf;
        STRLEN mlen;
        sockbuf = SvPVx(*++MARK, mlen);
        /* length is really flags */
        retval = PerlSock_sendto(PerlIO_fileno(IoIFP(io)), buffer, blen,
                                 length, (struct sockaddr *)sockbuf, mlen);
    }
    else
        /* length is really flags */
        retval = PerlSock_send(PerlIO_fileno(IoIFP(io)), buffer, blen, length);
#else
    else
        DIE(aTHX_ PL_no_sock_func, "send");
#endif
    if (retval < 0)
        goto say_undef;
    SP = ORIGMARK;
    if (DO_UTF8(bufsv))
        retval = utf8_length((U8*)buffer, (U8*)buffer + retval);
#if Size_t_size > IVSIZE
    PUSHn(retval);
#else
    PUSHi(retval);
#endif
    RETURN;

  say_undef:
    SP = ORIGMARK;
    RETPUSHUNDEF;
}

PP(pp_recv)
{
    return pp_sysread();
}

PP(pp_eof)
{
    dSP;
    GV *gv;
    IO *io;
    MAGIC *mg;

    if (MAXARG == 0) {
        if (PL_op->op_flags & OPf_SPECIAL) {    /* eof() */
            IO *io;
            gv = PL_last_in_gv = GvEGV(PL_argvgv);
            io = GvIO(gv);
            if (io && !IoIFP(io)) {
                if ((IoFLAGS(io) & IOf_START) && av_len(GvAVn(gv)) < 0) {
                    IoLINES(io) = 0;
                    IoFLAGS(io) &= ~IOf_START;
                    do_open(gv, "-", 1, FALSE, O_RDONLY, 0, Nullfp);
                    sv_setpvn(GvSV(gv), "-", 1);
                    SvSETMAGIC(GvSV(gv));
                }
                else if (!nextargv(gv))
                    RETPUSHYES;
            }
        }
        else
            gv = PL_last_in_gv;                 /* eof */
    }
    else
        gv = PL_last_in_gv = (GV*)POPs;         /* eof(FH) */

    if (gv && (io = GvIO(gv))
        && (mg = SvTIED_mg((SV*)io, PERL_MAGIC_tiedscalar)))
    {
        PUSHMARK(SP);
        XPUSHs(SvTIED_obj((SV*)io, mg));
        PUTBACK;
        ENTER;
        call_method("EOF", G_SCALAR);
        LEAVE;
        SPAGAIN;
        RETURN;
    }

    PUSHs(boolSV(!gv || do_eof(gv)));
    RETURN;
}

PP(pp_tell)
{
    dSP; dTARGET;
    GV *gv;
    IO *io;
    MAGIC *mg;

    if (MAXARG == 0)
        gv = PL_last_in_gv;
    else
        gv = PL_last_in_gv = (GV*)POPs;

    if (gv && (io = GvIO(gv))
        && (mg = SvTIED_mg((SV*)io, PERL_MAGIC_tiedscalar)))
    {
        PUSHMARK(SP);
        XPUSHs(SvTIED_obj((SV*)io, mg));
        PUTBACK;
        ENTER;
        call_method("TELL", G_SCALAR);
        LEAVE;
        SPAGAIN;
        RETURN;
    }

#if LSEEKSIZE > IVSIZE
    PUSHn( do_tell(gv) );
#else
    PUSHi( do_tell(gv) );
#endif
    RETURN;
}

PP(pp_seek)
{
    return pp_sysseek();
}

PP(pp_sysseek)
{
    dSP;
    GV *gv;
    IO *io;
    int whence = POPi;
#if LSEEKSIZE > IVSIZE
    Off_t offset = (Off_t)SvNVx(POPs);
#else
    Off_t offset = (Off_t)SvIVx(POPs);
#endif
    MAGIC *mg;

    gv = PL_last_in_gv = (GV*)POPs;

    if (gv && (io = GvIO(gv))
        && (mg = SvTIED_mg((SV*)io, PERL_MAGIC_tiedscalar)))
    {
        PUSHMARK(SP);
        XPUSHs(SvTIED_obj((SV*)io, mg));
#if LSEEKSIZE > IVSIZE
        XPUSHs(sv_2mortal(newSVnv((NV) offset)));
#else
        XPUSHs(sv_2mortal(newSViv(offset)));
#endif
        XPUSHs(sv_2mortal(newSViv(whence)));
        PUTBACK;
        ENTER;
        call_method("SEEK", G_SCALAR);
        LEAVE;
        SPAGAIN;
        RETURN;
    }

    if (PL_op->op_type == OP_SEEK)
        PUSHs(boolSV(do_seek(gv, offset, whence)));
    else {
        Off_t sought = do_sysseek(gv, offset, whence);
        if (sought < 0)
            PUSHs(&PL_sv_undef);
        else {
            SV* sv = sought ?
#if LSEEKSIZE > IVSIZE
                newSVnv((NV)sought)
#else
                newSViv(sought)
#endif
                : newSVpvn(zero_but_true, ZBTLEN);
            PUSHs(sv_2mortal(sv));
        }
    }
    RETURN;
}

PP(pp_truncate)
{
    dSP;
    /* There seems to be no consensus on the length type of truncate()
     * and ftruncate(), both off_t and size_t have supporters. In
     * general one would think that when using large files, off_t is
     * at least as wide as size_t, so using an off_t should be okay. */
    /* XXX Configure probe for the length type of *truncate() needed XXX */
    Off_t len;

#if Off_t_size > IVSIZE
    len = (Off_t)POPn;
#else
    len = (Off_t)POPi;
#endif
    /* Checking for length < 0 is problematic as the type might or
     * might not be signed: if it is not, clever compilers will moan. */
    /* XXX Configure probe for the signedness of the length type of *truncate() needed? XXX */
    SETERRNO(0,0);
    {
        STRLEN n_a;
        int result = 1;
        GV *tmpgv;
        IO *io;

        if (PL_op->op_flags & OPf_SPECIAL) {
            tmpgv = gv_fetchpv(POPpx, FALSE, SVt_PVIO);

        do_ftruncate_gv:
            if (!GvIO(tmpgv))
                result = 0;
            else {
                PerlIO *fp;
                io = GvIOp(tmpgv);
            do_ftruncate_io:
                TAINT_PROPER("truncate");
                if (!(fp = IoIFP(io))) {
                    result = 0;
                }
                else {
                    PerlIO_flush(fp);
#ifdef HAS_TRUNCATE
                    if (ftruncate(PerlIO_fileno(fp), len) < 0)
#else
                    if (my_chsize(PerlIO_fileno(fp), len) < 0)
#endif
                        result = 0;
                }
            }
        }
        else {
            SV *sv = POPs;
            char *name;
        
            if (SvTYPE(sv) == SVt_PVGV) {
                tmpgv = (GV*)sv;                /* *main::FRED for example */
                goto do_ftruncate_gv;
            }
            else if (SvROK(sv) && SvTYPE(SvRV(sv)) == SVt_PVGV) {
                tmpgv = (GV*) SvRV(sv); /* \*main::FRED for example */
                goto do_ftruncate_gv;
            }
            else if (SvROK(sv) && SvTYPE(SvRV(sv)) == SVt_PVIO) {
                io = (IO*) SvRV(sv); /* *main::FRED{IO} for example */
                goto do_ftruncate_io;
            }

            name = SvPV(sv, n_a);
            TAINT_PROPER("truncate");
#ifdef HAS_TRUNCATE
            if (truncate(name, len) < 0)
                result = 0;
#else
            {
                int tmpfd;

                if ((tmpfd = PerlLIO_open(name, O_RDWR)) < 0)
                    result = 0;
                else {
                    if (my_chsize(tmpfd, len) < 0)
                        result = 0;
                    PerlLIO_close(tmpfd);
                }
            }
#endif
        }

        if (result)
            RETPUSHYES;
        if (!errno)
            SETERRNO(EBADF,RMS_IFI);
        RETPUSHUNDEF;
    }
}

PP(pp_fcntl)
{
    return pp_ioctl();
}

PP(pp_ioctl)
{
    dSP; dTARGET;
    SV *argsv = POPs;
    unsigned int func = POPu;
    int optype = PL_op->op_type;
    char *s;
    IV retval;
    GV *gv = (GV*)POPs;
    IO *io = gv ? GvIOn(gv) : 0;

    if (!io || !argsv || !IoIFP(io)) {
        if (ckWARN2(WARN_UNOPENED,WARN_CLOSED))
            report_evil_fh(gv, io, PL_op->op_type);
        SETERRNO(EBADF,RMS_IFI);        /* well, sort of... */
        RETPUSHUNDEF;
    }

    if (SvPOK(argsv) || !SvNIOK(argsv)) {
        STRLEN len;
        STRLEN need;
        s = SvPV_force(argsv, len);
        need = IOCPARM_LEN(func);
        if (len < need) {
            s = Sv_Grow(argsv, need + 1);
            SvCUR_set(argsv, need);
        }

        s[SvCUR(argsv)] = 17;   /* a little sanity check here */
    }
    else {
        retval = SvIV(argsv);
        s = INT2PTR(char*,retval);              /* ouch */
    }

    TAINT_PROPER(optype == OP_IOCTL ? "ioctl" : "fcntl");

    if (optype == OP_IOCTL)
#ifdef HAS_IOCTL
        retval = PerlLIO_ioctl(PerlIO_fileno(IoIFP(io)), func, s);
#else
        DIE(aTHX_ "ioctl is not implemented");
#endif
    else
#ifndef HAS_FCNTL
      DIE(aTHX_ "fcntl is not implemented");
#else
#if defined(OS2) && defined(__EMX__)
        retval = fcntl(PerlIO_fileno(IoIFP(io)), func, (int)s);
#else
        retval = fcntl(PerlIO_fileno(IoIFP(io)), func, s);
#endif
#endif

#if defined(HAS_IOCTL) || defined(HAS_FCNTL)
    if (SvPOK(argsv)) {
        if (s[SvCUR(argsv)] != 17)
            DIE(aTHX_ "Possible memory corruption: %s overflowed 3rd argument",
                OP_NAME(PL_op));
        s[SvCUR(argsv)] = 0;            /* put our null back */
        SvSETMAGIC(argsv);              /* Assume it has changed */
    }

    if (retval == -1)
        RETPUSHUNDEF;
    if (retval != 0) {
        PUSHi(retval);
    }
    else {
        PUSHp(zero_but_true, ZBTLEN);
    }
#endif
    RETURN;
}

PP(pp_flock)
{
#ifdef FLOCK
    dSP; dTARGET;
    I32 value;
    int argtype;
    GV *gv;
    IO *io = NULL;
    PerlIO *fp;

    argtype = POPi;
    if (MAXARG == 0)
        gv = PL_last_in_gv;
    else
        gv = (GV*)POPs;
    if (gv && (io = GvIO(gv)))
        fp = IoIFP(io);
    else {
        fp = Nullfp;
        io = NULL;
    }
    if (fp) {
        (void)PerlIO_flush(fp);
        value = (I32)(PerlLIO_flock(PerlIO_fileno(fp), argtype) >= 0);
    }
    else {
        if (ckWARN2(WARN_UNOPENED,WARN_CLOSED))
            report_evil_fh(gv, io, PL_op->op_type);
        value = 0;
        SETERRNO(EBADF,RMS_IFI);
    }
    PUSHi(value);
    RETURN;
#else
    DIE(aTHX_ PL_no_func, "flock()");
#endif
}

/* Sockets. */

PP(pp_socket)
{
#ifdef HAS_SOCKET
    dSP;
    GV *gv;
    register IO *io;
    int protocol = POPi;
    int type = POPi;
    int domain = POPi;
    int fd;

    gv = (GV*)POPs;
    io = gv ? GvIOn(gv) : NULL;

    if (!gv || !io) {
        if (ckWARN2(WARN_UNOPENED,WARN_CLOSED))
            report_evil_fh(gv, io, PL_op->op_type);
        if (IoIFP(io))
            do_close(gv, FALSE);
        SETERRNO(EBADF,LIB_INVARG);
        RETPUSHUNDEF;
    }

    if (IoIFP(io))
        do_close(gv, FALSE);

    TAINT_PROPER("socket");
    fd = PerlSock_socket(domain, type, protocol);
    if (fd < 0)
        RETPUSHUNDEF;
    IoIFP(io) = PerlIO_fdopen(fd, "r"SOCKET_OPEN_MODE); /* stdio gets confused about sockets */
    IoOFP(io) = PerlIO_fdopen(fd, "w"SOCKET_OPEN_MODE);
    IoTYPE(io) = IoTYPE_SOCKET;
    if (!IoIFP(io) || !IoOFP(io)) {
        if (IoIFP(io)) PerlIO_close(IoIFP(io));
        if (IoOFP(io)) PerlIO_close(IoOFP(io));
        if (!IoIFP(io) && !IoOFP(io)) PerlLIO_close(fd);
        RETPUSHUNDEF;
    }
#if defined(HAS_FCNTL) && defined(F_SETFD)
    fcntl(fd, F_SETFD, fd > PL_maxsysfd);       /* ensure close-on-exec */
#endif

#ifdef EPOC
    setbuf( IoIFP(io), NULL); /* EPOC gets confused about sockets */
#endif

    RETPUSHYES;
#else
    DIE(aTHX_ PL_no_sock_func, "socket");
#endif
}

PP(pp_sockpair)
{
#if defined (HAS_SOCKETPAIR) || (defined (HAS_SOCKET) && defined(SOCK_DGRAM) && defined(AF_INET) && defined(PF_INET))
    dSP;
    GV *gv1;
    GV *gv2;
    register IO *io1;
    register IO *io2;
    int protocol = POPi;
    int type = POPi;
    int domain = POPi;
    int fd[2];

    gv2 = (GV*)POPs;
    gv1 = (GV*)POPs;
    io1 = gv1 ? GvIOn(gv1) : NULL;
    io2 = gv2 ? GvIOn(gv2) : NULL;
    if (!gv1 || !gv2 || !io1 || !io2) {
        if (ckWARN2(WARN_UNOPENED,WARN_CLOSED)) {
            if (!gv1 || !io1)
                report_evil_fh(gv1, io1, PL_op->op_type);
            if (!gv2 || !io2)
                report_evil_fh(gv1, io2, PL_op->op_type);
        }
        if (IoIFP(io1))
            do_close(gv1, FALSE);
        if (IoIFP(io2))
            do_close(gv2, FALSE);
        RETPUSHUNDEF;
    }

    if (IoIFP(io1))
        do_close(gv1, FALSE);
    if (IoIFP(io2))
        do_close(gv2, FALSE);

    TAINT_PROPER("socketpair");
    if (PerlSock_socketpair(domain, type, protocol, fd) < 0)
        RETPUSHUNDEF;
    IoIFP(io1) = PerlIO_fdopen(fd[0], "r"SOCKET_OPEN_MODE);
    IoOFP(io1) = PerlIO_fdopen(fd[0], "w"SOCKET_OPEN_MODE);
    IoTYPE(io1) = IoTYPE_SOCKET;
    IoIFP(io2) = PerlIO_fdopen(fd[1], "r"SOCKET_OPEN_MODE);
    IoOFP(io2) = PerlIO_fdopen(fd[1], "w"SOCKET_OPEN_MODE);
    IoTYPE(io2) = IoTYPE_SOCKET;
    if (!IoIFP(io1) || !IoOFP(io1) || !IoIFP(io2) || !IoOFP(io2)) {
        if (IoIFP(io1)) PerlIO_close(IoIFP(io1));
        if (IoOFP(io1)) PerlIO_close(IoOFP(io1));
        if (!IoIFP(io1) && !IoOFP(io1)) PerlLIO_close(fd[0]);
        if (IoIFP(io2)) PerlIO_close(IoIFP(io2));
        if (IoOFP(io2)) PerlIO_close(IoOFP(io2));
        if (!IoIFP(io2) && !IoOFP(io2)) PerlLIO_close(fd[1]);
        RETPUSHUNDEF;
    }
#if defined(HAS_FCNTL) && defined(F_SETFD)
    fcntl(fd[0],F_SETFD,fd[0] > PL_maxsysfd);   /* ensure close-on-exec */
    fcntl(fd[1],F_SETFD,fd[1] > PL_maxsysfd);   /* ensure close-on-exec */
#endif

    RETPUSHYES;
#else
    DIE(aTHX_ PL_no_sock_func, "socketpair");
#endif
}

PP(pp_bind)
{
#ifdef HAS_SOCKET
    dSP;
#ifdef MPE /* Requires PRIV mode to bind() to ports < 1024 */
    extern void GETPRIVMODE();
    extern void GETUSERMODE();
#endif
    SV *addrsv = POPs;
    char *addr;
    GV *gv = (GV*)POPs;
    register IO *io = GvIOn(gv);
    STRLEN len;
    int bind_ok = 0;
#ifdef MPE
    int mpeprivmode = 0;
#endif

    if (!io || !IoIFP(io))
        goto nuts;

    addr = SvPV(addrsv, len);
    TAINT_PROPER("bind");
#ifdef MPE /* Deal with MPE bind() peculiarities */
    if (((struct sockaddr *)addr)->sa_family == AF_INET) {
        /* The address *MUST* stupidly be zero. */
        ((struct sockaddr_in *)addr)->sin_addr.s_addr = INADDR_ANY;
        /* PRIV mode is required to bind() to ports < 1024. */
        if (((struct sockaddr_in *)addr)->sin_port < 1024 &&
            ((struct sockaddr_in *)addr)->sin_port > 0) {
            GETPRIVMODE(); /* If this fails, we are aborted by MPE/iX. */
            mpeprivmode = 1;
        }
    }
#endif /* MPE */
    if (PerlSock_bind(PerlIO_fileno(IoIFP(io)),
                      (struct sockaddr *)addr, len) >= 0)
        bind_ok = 1;

#ifdef MPE /* Switch back to USER mode */
    if (mpeprivmode)
        GETUSERMODE();
#endif /* MPE */

    if (bind_ok)
        RETPUSHYES;
    else
        RETPUSHUNDEF;

nuts:
    if (ckWARN(WARN_CLOSED))
        report_evil_fh(gv, io, PL_op->op_type);
    SETERRNO(EBADF,SS_IVCHAN);
    RETPUSHUNDEF;
#else
    DIE(aTHX_ PL_no_sock_func, "bind");
#endif
}

PP(pp_connect)
{
#ifdef HAS_SOCKET
    dSP;
    SV *addrsv = POPs;
    char *addr;
    GV *gv = (GV*)POPs;
    register IO *io = GvIOn(gv);
    STRLEN len;

    if (!io || !IoIFP(io))
        goto nuts;

    addr = SvPV(addrsv, len);
    TAINT_PROPER("connect");
    if (PerlSock_connect(PerlIO_fileno(IoIFP(io)), (struct sockaddr *)addr, len) >= 0)
        RETPUSHYES;
    else
        RETPUSHUNDEF;

nuts:
    if (ckWARN(WARN_CLOSED))
        report_evil_fh(gv, io, PL_op->op_type);
    SETERRNO(EBADF,SS_IVCHAN);
    RETPUSHUNDEF;
#else
    DIE(aTHX_ PL_no_sock_func, "connect");
#endif
}

PP(pp_listen)
{
#ifdef HAS_SOCKET
    dSP;
    int backlog = POPi;
    GV *gv = (GV*)POPs;
    register IO *io = gv ? GvIOn(gv) : NULL;

    if (!gv || !io || !IoIFP(io))
        goto nuts;

    if (PerlSock_listen(PerlIO_fileno(IoIFP(io)), backlog) >= 0)
        RETPUSHYES;
    else
        RETPUSHUNDEF;

nuts:
    if (ckWARN(WARN_CLOSED))
        report_evil_fh(gv, io, PL_op->op_type);
    SETERRNO(EBADF,SS_IVCHAN);
    RETPUSHUNDEF;
#else
    DIE(aTHX_ PL_no_sock_func, "listen");
#endif
}

PP(pp_accept)
{
#ifdef HAS_SOCKET
    dSP; dTARGET;
    GV *ngv;
    GV *ggv;
    register IO *nstio;
    register IO *gstio;
    char namebuf[MAXPATHLEN];
#if (defined(VMS_DO_SOCKETS) && defined(DECCRTL_SOCKETS)) || defined(MPE) || defined(__QNXNTO__)
    Sock_size_t len = sizeof (struct sockaddr_in);
#else
    Sock_size_t len = sizeof namebuf;
#endif
    int fd;

    ggv = (GV*)POPs;
    ngv = (GV*)POPs;

    if (!ngv)
        goto badexit;
    if (!ggv)
        goto nuts;

    gstio = GvIO(ggv);
    if (!gstio || !IoIFP(gstio))
        goto nuts;

    nstio = GvIOn(ngv);
    fd = PerlSock_accept(PerlIO_fileno(IoIFP(gstio)), (struct sockaddr *) namebuf, &len);
    if (fd < 0)
        goto badexit;
    if (IoIFP(nstio))
        do_close(ngv, FALSE);
    IoIFP(nstio) = PerlIO_fdopen(fd, "r"SOCKET_OPEN_MODE);
    IoOFP(nstio) = PerlIO_fdopen(fd, "w"SOCKET_OPEN_MODE);
    IoTYPE(nstio) = IoTYPE_SOCKET;
    if (!IoIFP(nstio) || !IoOFP(nstio)) {
        if (IoIFP(nstio)) PerlIO_close(IoIFP(nstio));
        if (IoOFP(nstio)) PerlIO_close(IoOFP(nstio));
        if (!IoIFP(nstio) && !IoOFP(nstio)) PerlLIO_close(fd);
        goto badexit;
    }
#if defined(HAS_FCNTL) && defined(F_SETFD)
    fcntl(fd, F_SETFD, fd > PL_maxsysfd);       /* ensure close-on-exec */
#endif

#ifdef EPOC
    len = sizeof (struct sockaddr_in); /* EPOC somehow truncates info */
    setbuf( IoIFP(nstio), NULL); /* EPOC gets confused about sockets */
#endif
#ifdef __SCO_VERSION__
    len = sizeof (struct sockaddr_in); /* OpenUNIX 8 somehow truncates info */
#endif

    PUSHp(namebuf, len);
    RETURN;

nuts:
    if (ckWARN(WARN_CLOSED))
        report_evil_fh(ggv, ggv ? GvIO(ggv) : 0, PL_op->op_type);
    SETERRNO(EBADF,SS_IVCHAN);

badexit:
    RETPUSHUNDEF;

#else
    DIE(aTHX_ PL_no_sock_func, "accept");
#endif
}

PP(pp_shutdown)
{
#ifdef HAS_SOCKET
    dSP; dTARGET;
    int how = POPi;
    GV *gv = (GV*)POPs;
    register IO *io = GvIOn(gv);

    if (!io || !IoIFP(io))
        goto nuts;

    PUSHi( PerlSock_shutdown(PerlIO_fileno(IoIFP(io)), how) >= 0 );
    RETURN;

nuts:
    if (ckWARN(WARN_CLOSED))
        report_evil_fh(gv, io, PL_op->op_type);
    SETERRNO(EBADF,SS_IVCHAN);
    RETPUSHUNDEF;
#else
    DIE(aTHX_ PL_no_sock_func, "shutdown");
#endif
}

PP(pp_gsockopt)
{
#ifdef HAS_SOCKET
    return pp_ssockopt();
#else
    DIE(aTHX_ PL_no_sock_func, "getsockopt");
#endif
}

PP(pp_ssockopt)
{
#ifdef HAS_SOCKET
    dSP;
    int optype = PL_op->op_type;
    SV *sv;
    int fd;
    unsigned int optname;
    unsigned int lvl;
    GV *gv;
    register IO *io;
    Sock_size_t len;

    if (optype == OP_GSOCKOPT)
        sv = sv_2mortal(NEWSV(22, 257));
    else
        sv = POPs;
    optname = (unsigned int) POPi;
    lvl = (unsigned int) POPi;

    gv = (GV*)POPs;
    io = GvIOn(gv);
    if (!io || !IoIFP(io))
        goto nuts;

    fd = PerlIO_fileno(IoIFP(io));
    switch (optype) {
    case OP_GSOCKOPT:
        SvGROW(sv, 257);
        (void)SvPOK_only(sv);
        SvCUR_set(sv,256);
        *SvEND(sv) ='\0';
        len = SvCUR(sv);
        if (PerlSock_getsockopt(fd, lvl, optname, SvPVX(sv), &len) < 0)
            goto nuts2;
        SvCUR_set(sv, len);
        *SvEND(sv) ='\0';
        PUSHs(sv);
        break;
    case OP_SSOCKOPT: {
            char *buf;
            int aint;
            if (SvPOKp(sv)) {
                STRLEN l;
                buf = SvPV(sv, l);
                len = l;
            }
            else {
                aint = (int)SvIV(sv);
                buf = (char*)&aint;
                len = sizeof(int);
            }
            if (PerlSock_setsockopt(fd, lvl, optname, buf, len) < 0)
                goto nuts2;
            PUSHs(&PL_sv_yes);
        }
        break;
    }
    RETURN;

nuts:
    if (ckWARN(WARN_CLOSED))
        report_evil_fh(gv, io, optype);
    SETERRNO(EBADF,SS_IVCHAN);
nuts2:
    RETPUSHUNDEF;

#else
    DIE(aTHX_ PL_no_sock_func, "setsockopt");
#endif
}

PP(pp_getsockname)
{
#ifdef HAS_SOCKET
    return pp_getpeername();
#else
    DIE(aTHX_ PL_no_sock_func, "getsockname");
#endif
}

PP(pp_getpeername)
{
#ifdef HAS_SOCKET
    dSP;
    int optype = PL_op->op_type;
    SV *sv;
    int fd;
    GV *gv = (GV*)POPs;
    register IO *io = GvIOn(gv);
    Sock_size_t len;

    if (!io || !IoIFP(io))
        goto nuts;

    sv = sv_2mortal(NEWSV(22, 257));
    (void)SvPOK_only(sv);
    len = 256;
    SvCUR_set(sv, len);
    *SvEND(sv) ='\0';
    fd = PerlIO_fileno(IoIFP(io));
    switch (optype) {
    case OP_GETSOCKNAME:
        if (PerlSock_getsockname(fd, (struct sockaddr *)SvPVX(sv), &len) < 0)
            goto nuts2;
        break;
    case OP_GETPEERNAME:
        if (PerlSock_getpeername(fd, (struct sockaddr *)SvPVX(sv), &len) < 0)
            goto nuts2;
#if defined(VMS_DO_SOCKETS) && defined (DECCRTL_SOCKETS)
        {
            static const char nowhere[] = "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";
            /* If the call succeeded, make sure we don't have a zeroed port/addr */
            if (((struct sockaddr *)SvPVX(sv))->sa_family == AF_INET &&
                !memcmp((char *)SvPVX(sv) + sizeof(u_short), nowhere,
                        sizeof(u_short) + sizeof(struct in_addr))) {
                goto nuts2;     
            }
        }
#endif
        break;
    }
#ifdef BOGUS_GETNAME_RETURN
    /* Interactive Unix, getpeername() and getsockname()
      does not return valid namelen */
    if (len == BOGUS_GETNAME_RETURN)
        len = sizeof(struct sockaddr);
#endif
    SvCUR_set(sv, len);
    *SvEND(sv) ='\0';
    PUSHs(sv);
    RETURN;

nuts:
    if (ckWARN(WARN_CLOSED))
        report_evil_fh(gv, io, optype);
    SETERRNO(EBADF,SS_IVCHAN);
nuts2:
    RETPUSHUNDEF;

#else
    DIE(aTHX_ PL_no_sock_func, "getpeername");
#endif
}

/* Stat calls. */

PP(pp_lstat)
{
    return pp_stat();
}

PP(pp_stat)
{
    dSP;
    GV *gv;
    I32 gimme;
    I32 max = 13;
    STRLEN n_a;

    if (PL_op->op_flags & OPf_REF) {
        gv = cGVOP_gv;
        if (PL_op->op_type == OP_LSTAT) {
            if (gv != PL_defgv) {
                if (ckWARN(WARN_IO))
                    Perl_warner(aTHX_ packWARN(WARN_IO),
                        "lstat() on filehandle %s", GvENAME(gv));
            } else if (PL_laststype != OP_LSTAT)
                Perl_croak(aTHX_ "The stat preceding lstat() wasn't an lstat");
        }

      do_fstat:
        if (gv != PL_defgv) {
            PL_laststype = OP_STAT;
            PL_statgv = gv;
            sv_setpv(PL_statname, "");
            PL_laststatval = (GvIO(gv) && IoIFP(GvIOp(gv))
                ? PerlLIO_fstat(PerlIO_fileno(IoIFP(GvIOn(gv))), &PL_statcache) : -1);
        }
        if (PL_laststatval < 0) {
            if (ckWARN2(WARN_UNOPENED,WARN_CLOSED))
                report_evil_fh(gv, GvIO(gv), PL_op->op_type);
            max = 0;
        }
    }
    else {
        SV* sv = POPs;
        if (SvTYPE(sv) == SVt_PVGV) {
            gv = (GV*)sv;
            goto do_fstat;
        }
        else if (SvROK(sv) && SvTYPE(SvRV(sv)) == SVt_PVGV) {
            gv = (GV*)SvRV(sv);
            if (PL_op->op_type == OP_LSTAT && ckWARN(WARN_IO))
                Perl_warner(aTHX_ packWARN(WARN_IO),
                        "lstat() on filehandle %s", GvENAME(gv));
            goto do_fstat;
        }
        sv_setpv(PL_statname, SvPV(sv,n_a));
        PL_statgv = Nullgv;
        PL_laststype = PL_op->op_type;
        if (PL_op->op_type == OP_LSTAT)
            PL_laststatval = PerlLIO_lstat(SvPV(PL_statname, n_a), &PL_statcache);
        else
            PL_laststatval = PerlLIO_stat(SvPV(PL_statname, n_a), &PL_statcache);
        if (PL_laststatval < 0) {
            if (ckWARN(WARN_NEWLINE) && strchr(SvPV(PL_statname, n_a), '\n'))
                Perl_warner(aTHX_ packWARN(WARN_NEWLINE), PL_warn_nl, "stat");
            max = 0;
        }
    }

    gimme = GIMME_V;
    if (gimme != G_ARRAY) {
        if (gimme != G_VOID)
            XPUSHs(boolSV(max));
        RETURN;
    }
    if (max) {
        EXTEND(SP, max);
        EXTEND_MORTAL(max);
        PUSHs(sv_2mortal(newSViv(PL_statcache.st_dev)));
        PUSHs(sv_2mortal(newSViv(PL_statcache.st_ino)));
        PUSHs(sv_2mortal(newSVuv(PL_statcache.st_mode)));
        PUSHs(sv_2mortal(newSVuv(PL_statcache.st_nlink)));
#if Uid_t_size > IVSIZE
        PUSHs(sv_2mortal(newSVnv(PL_statcache.st_uid)));
#else
#   if Uid_t_sign <= 0
        PUSHs(sv_2mortal(newSViv(PL_statcache.st_uid)));
#   else
        PUSHs(sv_2mortal(newSVuv(PL_statcache.st_uid)));
#   endif
#endif
#if Gid_t_size > IVSIZE
        PUSHs(sv_2mortal(newSVnv(PL_statcache.st_gid)));
#else
#   if Gid_t_sign <= 0
        PUSHs(sv_2mortal(newSViv(PL_statcache.st_gid)));
#   else
        PUSHs(sv_2mortal(newSVuv(PL_statcache.st_gid)));
#   endif
#endif
#ifdef USE_STAT_RDEV
        PUSHs(sv_2mortal(newSViv(PL_statcache.st_rdev)));
#else
        PUSHs(sv_2mortal(newSVpvn("", 0)));
#endif
#if Off_t_size > IVSIZE
        PUSHs(sv_2mortal(newSVnv((NV)PL_statcache.st_size)));
#else
        PUSHs(sv_2mortal(newSViv(PL_statcache.st_size)));
#endif
#ifdef BIG_TIME
        PUSHs(sv_2mortal(newSVnv(PL_statcache.st_atime)));
        PUSHs(sv_2mortal(newSVnv(PL_statcache.st_mtime)));
        PUSHs(sv_2mortal(newSVnv(PL_statcache.st_ctime)));
#else
        PUSHs(sv_2mortal(newSViv(PL_statcache.st_atime)));
        PUSHs(sv_2mortal(newSViv(PL_statcache.st_mtime)));
        PUSHs(sv_2mortal(newSViv(PL_statcache.st_ctime)));
#endif
#ifdef USE_STAT_BLOCKS
        PUSHs(sv_2mortal(newSVuv(PL_statcache.st_blksize)));
        PUSHs(sv_2mortal(newSVuv(PL_statcache.st_blocks)));
#else
        PUSHs(sv_2mortal(newSVpvn("", 0)));
        PUSHs(sv_2mortal(newSVpvn("", 0)));
#endif
    }
    RETURN;
}

PP(pp_ftrread)
{
    I32 result;
    dSP;
#if defined(HAS_ACCESS) && defined(R_OK)
    STRLEN n_a;
    if ((PL_op->op_private & OPpFT_ACCESS) && SvPOK(TOPs)) {
        result = access(POPpx, R_OK);
        if (result == 0)
            RETPUSHYES;
        if (result < 0)
            RETPUSHUNDEF;
        RETPUSHNO;
    }
    else
        result = my_stat();
#else
    result = my_stat();
#endif
    SPAGAIN;
    if (result < 0)
        RETPUSHUNDEF;
    if (cando(S_IRUSR, 0, &PL_statcache))
        RETPUSHYES;
    RETPUSHNO;
}

PP(pp_ftrwrite)
{
    I32 result;
    dSP;
#if defined(HAS_ACCESS) && defined(W_OK)
    STRLEN n_a;
    if ((PL_op->op_private & OPpFT_ACCESS) && SvPOK(TOPs)) {
        result = access(POPpx, W_OK);
        if (result == 0)
            RETPUSHYES;
        if (result < 0)
            RETPUSHUNDEF;
        RETPUSHNO;
    }
    else
        result = my_stat();
#else
    result = my_stat();
#endif
    SPAGAIN;
    if (result < 0)
        RETPUSHUNDEF;
    if (cando(S_IWUSR, 0, &PL_statcache))
        RETPUSHYES;
    RETPUSHNO;
}

PP(pp_ftrexec)
{
    I32 result;
    dSP;
#if defined(HAS_ACCESS) && defined(X_OK)
    STRLEN n_a;
    if ((PL_op->op_private & OPpFT_ACCESS) && SvPOK(TOPs)) {
        result = access(POPpx, X_OK);
        if (result == 0)
            RETPUSHYES;
        if (result < 0)
            RETPUSHUNDEF;
        RETPUSHNO;
    }
    else
        result = my_stat();
#else
    result = my_stat();
#endif
    SPAGAIN;
    if (result < 0)
        RETPUSHUNDEF;
    if (cando(S_IXUSR, 0, &PL_statcache))
        RETPUSHYES;
    RETPUSHNO;
}

PP(pp_fteread)
{
    I32 result;
    dSP;
#ifdef PERL_EFF_ACCESS_R_OK
    STRLEN n_a;
    if ((PL_op->op_private & OPpFT_ACCESS) && SvPOK(TOPs)) {
        result = PERL_EFF_ACCESS_R_OK(POPpx);
        if (result == 0)
            RETPUSHYES;
        if (result < 0)
            RETPUSHUNDEF;
        RETPUSHNO;
    }
    else
        result = my_stat();
#else
    result = my_stat();
#endif
    SPAGAIN;
    if (result < 0)
        RETPUSHUNDEF;
    if (cando(S_IRUSR, 1, &PL_statcache))
        RETPUSHYES;
    RETPUSHNO;
}

PP(pp_ftewrite)
{
    I32 result;
    dSP;
#ifdef PERL_EFF_ACCESS_W_OK
    STRLEN n_a;
    if ((PL_op->op_private & OPpFT_ACCESS) && SvPOK(TOPs)) {
        result = PERL_EFF_ACCESS_W_OK(POPpx);
        if (result == 0)
            RETPUSHYES;
        if (result < 0)
            RETPUSHUNDEF;
        RETPUSHNO;
    }
    else
        result = my_stat();
#else
    result = my_stat();
#endif
    SPAGAIN;
    if (result < 0)
        RETPUSHUNDEF;
    if (cando(S_IWUSR, 1, &PL_statcache))
        RETPUSHYES;
    RETPUSHNO;
}

PP(pp_fteexec)
{
    I32 result;
    dSP;
#ifdef PERL_EFF_ACCESS_X_OK
    STRLEN n_a;
    if ((PL_op->op_private & OPpFT_ACCESS) && SvPOK(TOPs)) {
        result = PERL_EFF_ACCESS_X_OK(POPpx);
        if (result == 0)
            RETPUSHYES;
        if (result < 0)
            RETPUSHUNDEF;
        RETPUSHNO;
    }
    else
        result = my_stat();
#else
    result = my_stat();
#endif
    SPAGAIN;
    if (result < 0)
        RETPUSHUNDEF;
    if (cando(S_IXUSR, 1, &PL_statcache))
        RETPUSHYES;
    RETPUSHNO;
}

PP(pp_ftis)
{
    I32 result = my_stat();
    dSP;
    if (result < 0)
        RETPUSHUNDEF;
    RETPUSHYES;
}

PP(pp_fteowned)
{
    return pp_ftrowned();
}

PP(pp_ftrowned)
{
    I32 result = my_stat();
    dSP;
    if (result < 0)
        RETPUSHUNDEF;
    if (PL_statcache.st_uid == (PL_op->op_type == OP_FTEOWNED ?
                                PL_euid : PL_uid) )
        RETPUSHYES;
    RETPUSHNO;
}

PP(pp_ftzero)
{
    I32 result = my_stat();
    dSP;
    if (result < 0)
        RETPUSHUNDEF;
    if (PL_statcache.st_size == 0)
        RETPUSHYES;
    RETPUSHNO;
}

PP(pp_ftsize)
{
    I32 result = my_stat();
    dSP; dTARGET;
    if (result < 0)
        RETPUSHUNDEF;
#if Off_t_size > IVSIZE
    PUSHn(PL_statcache.st_size);
#else
    PUSHi(PL_statcache.st_size);
#endif
    RETURN;
}

PP(pp_ftmtime)
{
    I32 result = my_stat();
    dSP; dTARGET;
    if (result < 0)
        RETPUSHUNDEF;
    PUSHn( (((NV)PL_basetime - PL_statcache.st_mtime)) / 86400.0 );
    RETURN;
}

PP(pp_ftatime)
{
    I32 result = my_stat();
    dSP; dTARGET;
    if (result < 0)
        RETPUSHUNDEF;
    PUSHn( (((NV)PL_basetime - PL_statcache.st_atime)) / 86400.0 );
    RETURN;
}

PP(pp_ftctime)
{
    I32 result = my_stat();
    dSP; dTARGET;
    if (result < 0)
        RETPUSHUNDEF;
    PUSHn( (((NV)PL_basetime - PL_statcache.st_ctime)) / 86400.0 );
    RETURN;
}

PP(pp_ftsock)
{
    I32 result = my_stat();
    dSP;
    if (result < 0)
        RETPUSHUNDEF;
    if (S_ISSOCK(PL_statcache.st_mode))
        RETPUSHYES;
    RETPUSHNO;
}

PP(pp_ftchr)
{
    I32 result = my_stat();
    dSP;
    if (result < 0)
        RETPUSHUNDEF;
    if (S_ISCHR(PL_statcache.st_mode))
        RETPUSHYES;
    RETPUSHNO;
}

PP(pp_ftblk)
{
    I32 result = my_stat();
    dSP;
    if (result < 0)
        RETPUSHUNDEF;
    if (S_ISBLK(PL_statcache.st_mode))
        RETPUSHYES;
    RETPUSHNO;
}

PP(pp_ftfile)
{
    I32 result = my_stat();
    dSP;
    if (result < 0)
        RETPUSHUNDEF;
    if (S_ISREG(PL_statcache.st_mode))
        RETPUSHYES;
    RETPUSHNO;
}

PP(pp_ftdir)
{
    I32 result = my_stat();
    dSP;
    if (result < 0)
        RETPUSHUNDEF;
    if (S_ISDIR(PL_statcache.st_mode))
        RETPUSHYES;
    RETPUSHNO;
}

PP(pp_ftpipe)
{
    I32 result = my_stat();
    dSP;
    if (result < 0)
        RETPUSHUNDEF;
    if (S_ISFIFO(PL_statcache.st_mode))
        RETPUSHYES;
    RETPUSHNO;
}

PP(pp_ftlink)
{
    I32 result = my_lstat();
    dSP;
    if (result < 0)
        RETPUSHUNDEF;
    if (S_ISLNK(PL_statcache.st_mode))
        RETPUSHYES;
    RETPUSHNO;
}

PP(pp_ftsuid)
{
    dSP;
#ifdef S_ISUID
    I32 result = my_stat();
    SPAGAIN;
    if (result < 0)
        RETPUSHUNDEF;
    if (PL_statcache.st_mode & S_ISUID)
        RETPUSHYES;
#endif
    RETPUSHNO;
}

PP(pp_ftsgid)
{
    dSP;
#ifdef S_ISGID
    I32 result = my_stat();
    SPAGAIN;
    if (result < 0)
        RETPUSHUNDEF;
    if (PL_statcache.st_mode & S_ISGID)
        RETPUSHYES;
#endif
    RETPUSHNO;
}

PP(pp_ftsvtx)
{
    dSP;
#ifdef S_ISVTX
    I32 result = my_stat();
    SPAGAIN;
    if (result < 0)
        RETPUSHUNDEF;
    if (PL_statcache.st_mode & S_ISVTX)
        RETPUSHYES;
#endif
    RETPUSHNO;
}

PP(pp_fttty)
{
    dSP;
    int fd;
    GV *gv;
    char *tmps = Nullch;
    STRLEN n_a;

    if (PL_op->op_flags & OPf_REF)
        gv = cGVOP_gv;
    else if (isGV(TOPs))
        gv = (GV*)POPs;
    else if (SvROK(TOPs) && isGV(SvRV(TOPs)))
        gv = (GV*)SvRV(POPs);
    else
        gv = gv_fetchpv(tmps = POPpx, FALSE, SVt_PVIO);

    if (GvIO(gv) && IoIFP(GvIOp(gv)))
        fd = PerlIO_fileno(IoIFP(GvIOp(gv)));
    else if (tmps && isDIGIT(*tmps))
        fd = atoi(tmps);
    else
        RETPUSHUNDEF;
    if (PerlLIO_isatty(fd))
        RETPUSHYES;
    RETPUSHNO;
}

#if defined(atarist) /* this will work with atariST. Configure will
                        make guesses for other systems. */
# define FILE_base(f) ((f)->_base)
# define FILE_ptr(f) ((f)->_ptr)
# define FILE_cnt(f) ((f)->_cnt)
# define FILE_bufsiz(f) ((f)->_cnt + ((f)->_ptr - (f)->_base))
#endif

PP(pp_fttext)
{
    dSP;
    I32 i;
    I32 len;
    I32 odd = 0;
    STDCHAR tbuf[512];
    register STDCHAR *s;
    register IO *io;
    register SV *sv;
    GV *gv;
    STRLEN n_a;
    PerlIO *fp;

    if (PL_op->op_flags & OPf_REF)
        gv = cGVOP_gv;
    else if (isGV(TOPs))
        gv = (GV*)POPs;
    else if (SvROK(TOPs) && isGV(SvRV(TOPs)))
        gv = (GV*)SvRV(POPs);
    else
        gv = Nullgv;

    if (gv) {
        EXTEND(SP, 1);
        if (gv == PL_defgv) {
            if (PL_statgv)
                io = GvIO(PL_statgv);
            else {
                sv = PL_statname;
                goto really_filename;
            }
        }
        else {
            PL_statgv = gv;
            PL_laststatval = -1;
            sv_setpv(PL_statname, "");
            io = GvIO(PL_statgv);
        }
        if (io && IoIFP(io)) {
            if (! PerlIO_has_base(IoIFP(io)))
                DIE(aTHX_ "-T and -B not implemented on filehandles");
            PL_laststatval = PerlLIO_fstat(PerlIO_fileno(IoIFP(io)), &PL_statcache);
            if (PL_laststatval < 0)
                RETPUSHUNDEF;
            if (S_ISDIR(PL_statcache.st_mode)) { /* handle NFS glitch */
                if (PL_op->op_type == OP_FTTEXT)
                    RETPUSHNO;
                else
                    RETPUSHYES;
            }
            if (PerlIO_get_cnt(IoIFP(io)) <= 0) {
                i = PerlIO_getc(IoIFP(io));
                if (i != EOF)
                    (void)PerlIO_ungetc(IoIFP(io),i);
            }
            if (PerlIO_get_cnt(IoIFP(io)) <= 0) /* null file is anything */
                RETPUSHYES;
            len = PerlIO_get_bufsiz(IoIFP(io));
            s = (STDCHAR *) PerlIO_get_base(IoIFP(io));
            /* sfio can have large buffers - limit to 512 */
            if (len > 512)
                len = 512;
        }
        else {
            if (ckWARN2(WARN_UNOPENED,WARN_CLOSED)) {
                gv = cGVOP_gv;
                report_evil_fh(gv, GvIO(gv), PL_op->op_type);
            }
            SETERRNO(EBADF,RMS_IFI);
            RETPUSHUNDEF;
        }
    }
    else {
        sv = POPs;
      really_filename:
        PL_statgv = Nullgv;
        PL_laststype = OP_STAT;
        sv_setpv(PL_statname, SvPV(sv, n_a));
        if (!(fp = PerlIO_open(SvPVX(PL_statname), "r"))) {
            if (ckWARN(WARN_NEWLINE) && strchr(SvPV(PL_statname, n_a), '\n'))
                Perl_warner(aTHX_ packWARN(WARN_NEWLINE), PL_warn_nl, "open");
            RETPUSHUNDEF;
        }
        PL_laststatval = PerlLIO_fstat(PerlIO_fileno(fp), &PL_statcache);
        if (PL_laststatval < 0) {
            (void)PerlIO_close(fp);
            RETPUSHUNDEF;
        }
        PerlIO_binmode(aTHX_ fp, '<', O_BINARY, Nullch);
        len = PerlIO_read(fp, tbuf, sizeof(tbuf));
        (void)PerlIO_close(fp);
        if (len <= 0) {
            if (S_ISDIR(PL_statcache.st_mode) && PL_op->op_type == OP_FTTEXT)
                RETPUSHNO;              /* special case NFS directories */
            RETPUSHYES;         /* null file is anything */
        }
        s = tbuf;
    }

    /* now scan s to look for textiness */
    /*   XXX ASCII dependent code */

#if defined(DOSISH) || defined(USEMYBINMODE)
    /* ignore trailing ^Z on short files */
    if (len && len < sizeof(tbuf) && tbuf[len-1] == 26)
        --len;
#endif

    for (i = 0; i < len; i++, s++) {
        if (!*s) {                      /* null never allowed in text */
            odd += len;
            break;
        }
#ifdef EBCDIC
        else if (!(isPRINT(*s) || isSPACE(*s)))
            odd++;
#else
        else if (*s & 128) {
#ifdef USE_LOCALE
            if (IN_LOCALE_RUNTIME && isALPHA_LC(*s))
                continue;
#endif
            /* utf8 characters don't count as odd */
            if (UTF8_IS_START(*s)) {
                int ulen = UTF8SKIP(s);
                if (ulen < len - i) {
                    int j;
                    for (j = 1; j < ulen; j++) {
                        if (!UTF8_IS_CONTINUATION(s[j]))
                            goto not_utf8;
                    }
                    --ulen;     /* loop does extra increment */
                    s += ulen;
                    i += ulen;
                    continue;
                }
            }
          not_utf8:
            odd++;
        }
        else if (*s < 32 &&
          *s != '\n' && *s != '\r' && *s != '\b' &&
          *s != '\t' && *s != '\f' && *s != 27)
            odd++;
#endif
    }

    if ((odd * 3 > len) == (PL_op->op_type == OP_FTTEXT)) /* allow 1/3 odd */
        RETPUSHNO;
    else
        RETPUSHYES;
}

PP(pp_ftbinary)
{
    return pp_fttext();
}

/* File calls. */

PP(pp_chdir)
{
    dSP; dTARGET;
    char *tmps;
    SV **svp;
    STRLEN n_a;

    if( MAXARG == 1 )
        tmps = POPpx;
    else
        tmps = 0;

    if( !tmps || !*tmps ) {
        if (    (svp = hv_fetch(GvHVn(PL_envgv), "HOME", 4, FALSE))
             || (svp = hv_fetch(GvHVn(PL_envgv), "LOGDIR", 6, FALSE))
#ifdef VMS
             || (svp = hv_fetch(GvHVn(PL_envgv), "SYS$LOGIN", 9, FALSE))
#endif
           )
        {
            if( MAXARG == 1 )
                deprecate("chdir('') or chdir(undef) as chdir()");
            tmps = SvPV(*svp, n_a);
        }
        else {
            PUSHi(0);
            TAINT_PROPER("chdir");
            RETURN;
        }
    }

    TAINT_PROPER("chdir");
    PUSHi( PerlDir_chdir(tmps) >= 0 );
#ifdef VMS
    /* Clear the DEFAULT element of ENV so we'll get the new value
     * in the future. */
    hv_delete(GvHVn(PL_envgv),"DEFAULT",7,G_DISCARD);
#endif
    RETURN;
}

PP(pp_chown)
{
#ifdef HAS_CHOWN
    dSP; dMARK; dTARGET;
    I32 value = (I32)apply(PL_op->op_type, MARK, SP);

    SP = MARK;
    PUSHi(value);
    RETURN;
#else
    DIE(aTHX_ PL_no_func, "chown");
#endif
}

PP(pp_chroot)
{
#ifdef HAS_CHROOT
    dSP; dTARGET;
    STRLEN n_a;
    char *tmps = POPpx;
    TAINT_PROPER("chroot");
    PUSHi( chroot(tmps) >= 0 );
    RETURN;
#else
    DIE(aTHX_ PL_no_func, "chroot");
#endif
}

PP(pp_unlink)
{
    dSP; dMARK; dTARGET;
    I32 value;
    value = (I32)apply(PL_op->op_type, MARK, SP);
    SP = MARK;
    PUSHi(value);
    RETURN;
}

PP(pp_chmod)
{
    dSP; dMARK; dTARGET;
    I32 value;
    value = (I32)apply(PL_op->op_type, MARK, SP);
    SP = MARK;
    PUSHi(value);
    RETURN;
}

PP(pp_utime)
{
    dSP; dMARK; dTARGET;
    I32 value;
    value = (I32)apply(PL_op->op_type, MARK, SP);
    SP = MARK;
    PUSHi(value);
    RETURN;
}

PP(pp_rename)
{
    dSP; dTARGET;
    int anum;
    STRLEN n_a;

    char *tmps2 = POPpx;
    char *tmps = SvPV(TOPs, n_a);
    TAINT_PROPER("rename");
#ifdef HAS_RENAME
    anum = PerlLIO_rename(tmps, tmps2);
#else
    if (!(anum = PerlLIO_stat(tmps, &PL_statbuf))) {
        if (same_dirent(tmps2, tmps))   /* can always rename to same name */
            anum = 1;
        else {
            if (PL_euid || PerlLIO_stat(tmps2, &PL_statbuf) < 0 || !S_ISDIR(PL_statbuf.st_mode))
                (void)UNLINK(tmps2);
            if (!(anum = link(tmps, tmps2)))
                anum = UNLINK(tmps);
        }
    }
#endif
    SETi( anum >= 0 );
    RETURN;
}

PP(pp_link)
{
#ifdef HAS_LINK
    dSP; dTARGET;
    STRLEN n_a;
    char *tmps2 = POPpx;
    char *tmps = SvPV(TOPs, n_a);
    TAINT_PROPER("link");
    SETi( PerlLIO_link(tmps, tmps2) >= 0 );
    RETURN;
#else
    DIE(aTHX_ PL_no_func, "link");
#endif
}

PP(pp_symlink)
{
#ifdef HAS_SYMLINK
    dSP; dTARGET;
    STRLEN n_a;
    char *tmps2 = POPpx;
    char *tmps = SvPV(TOPs, n_a);
    TAINT_PROPER("symlink");
    SETi( symlink(tmps, tmps2) >= 0 );
    RETURN;
#else
    DIE(aTHX_ PL_no_func, "symlink");
#endif
}

PP(pp_readlink)
{
    dSP;
#ifdef HAS_SYMLINK
    dTARGET;
    char *tmps;
    char buf[MAXPATHLEN];
    int len;
    STRLEN n_a;

#ifndef INCOMPLETE_TAINTS
    TAINT;
#endif
    tmps = POPpx;
    len = readlink(tmps, buf, sizeof(buf) - 1);
    EXTEND(SP, 1);
    if (len < 0)
        RETPUSHUNDEF;
    PUSHp(buf, len);
    RETURN;
#else
    EXTEND(SP, 1);
    RETSETUNDEF;                /* just pretend it's a normal file */
#endif
}

#if !defined(HAS_MKDIR) || !defined(HAS_RMDIR)
STATIC int
S_dooneliner(pTHX_ char *cmd, char *filename)
{
    char *save_filename = filename;
    char *cmdline;
    char *s;
    PerlIO *myfp;
    int anum = 1;

    New(666, cmdline, strlen(cmd) + (strlen(filename) * 2) + 10, char);
    strcpy(cmdline, cmd);
    strcat(cmdline, " ");
    for (s = cmdline + strlen(cmdline); *filename; ) {
        *s++ = '\\';
        *s++ = *filename++;
    }
    strcpy(s, " 2>&1");
    myfp = PerlProc_popen(cmdline, "r");
    Safefree(cmdline);

    if (myfp) {
        SV *tmpsv = sv_newmortal();
        /* Need to save/restore 'PL_rs' ?? */
        s = sv_gets(tmpsv, myfp, 0);
        (void)PerlProc_pclose(myfp);
        if (s != Nullch) {
            int e;
            for (e = 1;
#ifdef HAS_SYS_ERRLIST
                 e <= sys_nerr
#endif
                 ; e++)
            {
                /* you don't see this */
                char *errmsg =
#ifdef HAS_SYS_ERRLIST
                    sys_errlist[e]
#else
                    strerror(e)
#endif
                    ;
                if (!errmsg)
                    break;
                if (instr(s, errmsg)) {
                    SETERRNO(e,0);
                    return 0;
                }
            }
            SETERRNO(0,0);
#ifndef EACCES
#define EACCES EPERM
#endif
            if (instr(s, "cannot make"))
                SETERRNO(EEXIST,RMS_FEX);
            else if (instr(s, "existing file"))
                SETERRNO(EEXIST,RMS_FEX);
            else if (instr(s, "ile exists"))
                SETERRNO(EEXIST,RMS_FEX);
            else if (instr(s, "non-exist"))
                SETERRNO(ENOENT,RMS_FNF);
            else if (instr(s, "does not exist"))
                SETERRNO(ENOENT,RMS_FNF);
            else if (instr(s, "not empty"))
                SETERRNO(EBUSY,SS_DEVOFFLINE);
            else if (instr(s, "cannot access"))
                SETERRNO(EACCES,RMS_PRV);
            else
                SETERRNO(EPERM,RMS_PRV);
            return 0;
        }
        else {  /* some mkdirs return no failure indication */
            anum = (PerlLIO_stat(save_filename, &PL_statbuf) >= 0);
            if (PL_op->op_type == OP_RMDIR)
                anum = !anum;
            if (anum)
                SETERRNO(0,0);
            else
                SETERRNO(EACCES,RMS_PRV);       /* a guess */
        }
        return anum;
    }
    else
        return 0;
}
#endif

/* This macro removes trailing slashes from a directory name.
 * Different operating and file systems take differently to
 * trailing slashes.  According to POSIX 1003.1 1996 Edition
 * any number of trailing slashes should be allowed.
 * Thusly we snip them away so that even non-conforming
 * systems are happy.
 * We should probably do this "filtering" for all
 * the functions that expect (potentially) directory names:
 * -d, chdir(), chmod(), chown(), chroot(), fcntl()?,
 * (mkdir()), opendir(), rename(), rmdir(), stat(). --jhi */

#define TRIMSLASHES(tmps,len,copy) (tmps) = SvPV(TOPs, (len)); \
    if ((len) > 1 && (tmps)[(len)-1] == '/') { \
        do { \
            (len)--; \
        } while ((len) > 1 && (tmps)[(len)-1] == '/'); \
        (tmps) = savepvn((tmps), (len)); \
        (copy) = TRUE; \
    }

PP(pp_mkdir)
{
    dSP; dTARGET;
    int mode;
#ifndef HAS_MKDIR
    int oldumask;
#endif
    STRLEN len;
    char *tmps;
    bool copy = FALSE;

    if (MAXARG > 1)
        mode = POPi;
    else
        mode = 0777;

    TRIMSLASHES(tmps,len,copy);

    TAINT_PROPER("mkdir");
#ifdef HAS_MKDIR
    SETi( PerlDir_mkdir(tmps, mode) >= 0 );
#else
    SETi( dooneliner("mkdir", tmps) );
    oldumask = PerlLIO_umask(0);
    PerlLIO_umask(oldumask);
    PerlLIO_chmod(tmps, (mode & ~oldumask) & 0777);
#endif
    if (copy)
        Safefree(tmps);
    RETURN;
}

PP(pp_rmdir)
{
    dSP; dTARGET;
    STRLEN len;
    char *tmps;
    bool copy = FALSE;

    TRIMSLASHES(tmps,len,copy);
    TAINT_PROPER("rmdir");
#ifdef HAS_RMDIR
    SETi( PerlDir_rmdir(tmps) >= 0 );
#else
    SETi( dooneliner("rmdir", tmps) );
#endif
    if (copy)
        Safefree(tmps);
    RETURN;
}

/* Directory calls. */

PP(pp_open_dir)
{
#if defined(Direntry_t) && defined(HAS_READDIR)
    dSP;
    STRLEN n_a;
    char *dirname = POPpx;
    GV *gv = (GV*)POPs;
    register IO *io = GvIOn(gv);

    if (!io)
        goto nope;

    if (IoDIRP(io))
        PerlDir_close(IoDIRP(io));
    if (!(IoDIRP(io) = PerlDir_open(dirname)))
        goto nope;

    RETPUSHYES;
nope:
    if (!errno)
        SETERRNO(EBADF,RMS_DIR);
    RETPUSHUNDEF;
#else
    DIE(aTHX_ PL_no_dir_func, "opendir");
#endif
}

PP(pp_readdir)
{
#if !defined(Direntry_t) || !defined(HAS_READDIR)
    DIE(aTHX_ PL_no_dir_func, "readdir");
#else
#if !defined(I_DIRENT) && !defined(VMS)
    Direntry_t *readdir (DIR *);
#endif
    dSP;

    SV *sv;
    I32 gimme = GIMME;
    GV *gv = (GV *)POPs;
    register Direntry_t *dp;
    register IO *io = GvIOn(gv);

    if (!io || !IoDIRP(io))
        goto nope;

    do {
        dp = (Direntry_t *)PerlDir_read(IoDIRP(io));
        if (!dp)
            break;
#ifdef DIRNAMLEN
        sv = newSVpvn(dp->d_name, dp->d_namlen);
#else
        sv = newSVpv(dp->d_name, 0);
#endif
#ifndef INCOMPLETE_TAINTS
        if (!(IoFLAGS(io) & IOf_UNTAINT))
            SvTAINTED_on(sv);
#endif
        XPUSHs(sv_2mortal(sv));
    }
    while (gimme == G_ARRAY);

    if (!dp && gimme != G_ARRAY)
        goto nope;

    RETURN;

nope:
    if (!errno)
        SETERRNO(EBADF,RMS_ISI);
    if (GIMME == G_ARRAY)
        RETURN;
    else
        RETPUSHUNDEF;
#endif
}

PP(pp_telldir)
{
#if defined(HAS_TELLDIR) || defined(telldir)
    dSP; dTARGET;
 /* XXX does _anyone_ need this? --AD 2/20/1998 */
 /* XXX netbsd still seemed to.
    XXX HAS_TELLDIR_PROTO is new style, NEED_TELLDIR_PROTO is old style.
    --JHI 1999-Feb-02 */
# if !defined(HAS_TELLDIR_PROTO) || defined(NEED_TELLDIR_PROTO)
    long telldir (DIR *);
# endif
    GV *gv = (GV*)POPs;
    register IO *io = GvIOn(gv);

    if (!io || !IoDIRP(io))
        goto nope;

    PUSHi( PerlDir_tell(IoDIRP(io)) );
    RETURN;
nope:
    if (!errno)
        SETERRNO(EBADF,RMS_ISI);
    RETPUSHUNDEF;
#else
    DIE(aTHX_ PL_no_dir_func, "telldir");
#endif
}

PP(pp_seekdir)
{
#if defined(HAS_SEEKDIR) || defined(seekdir)
    dSP;
    long along = POPl;
    GV *gv = (GV*)POPs;
    register IO *io = GvIOn(gv);

    if (!io || !IoDIRP(io))
        goto nope;

    (void)PerlDir_seek(IoDIRP(io), along);

    RETPUSHYES;
nope:
    if (!errno)
        SETERRNO(EBADF,RMS_ISI);
    RETPUSHUNDEF;
#else
    DIE(aTHX_ PL_no_dir_func, "seekdir");
#endif
}

PP(pp_rewinddir)
{
#if defined(HAS_REWINDDIR) || defined(rewinddir)
    dSP;
    GV *gv = (GV*)POPs;
    register IO *io = GvIOn(gv);

    if (!io || !IoDIRP(io))
        goto nope;

    (void)PerlDir_rewind(IoDIRP(io));
    RETPUSHYES;
nope:
    if (!errno)
        SETERRNO(EBADF,RMS_ISI);
    RETPUSHUNDEF;
#else
    DIE(aTHX_ PL_no_dir_func, "rewinddir");
#endif
}

PP(pp_closedir)
{
#if defined(Direntry_t) && defined(HAS_READDIR)
    dSP;
    GV *gv = (GV*)POPs;
    register IO *io = GvIOn(gv);

    if (!io || !IoDIRP(io))
        goto nope;

#ifdef VOID_CLOSEDIR
    PerlDir_close(IoDIRP(io));
#else
    if (PerlDir_close(IoDIRP(io)) < 0) {
        IoDIRP(io) = 0; /* Don't try to close again--coredumps on SysV */
        goto nope;
    }
#endif
    IoDIRP(io) = 0;

    RETPUSHYES;
nope:
    if (!errno)
        SETERRNO(EBADF,RMS_IFI);
    RETPUSHUNDEF;
#else
    DIE(aTHX_ PL_no_dir_func, "closedir");
#endif
}

/* Process control. */

PP(pp_fork)
{
#ifdef HAS_FORK
    dSP; dTARGET;
    Pid_t childpid;
    GV *tmpgv;

    EXTEND(SP, 1);
    PERL_FLUSHALL_FOR_CHILD;
    childpid = PerlProc_fork();
    if (childpid < 0)
        RETSETUNDEF;
    if (!childpid) {
        /*SUPPRESS 560*/
        if ((tmpgv = gv_fetchpv("$", TRUE, SVt_PV))) {
            SvREADONLY_off(GvSV(tmpgv));
            sv_setiv(GvSV(tmpgv), (IV)PerlProc_getpid());
            SvREADONLY_on(GvSV(tmpgv));
        }
#ifdef THREADS_HAVE_PIDS
        PL_ppid = (IV)getppid();
#endif
        hv_clear(PL_pidstatus); /* no kids, so don't wait for 'em */
    }
    PUSHi(childpid);
    RETURN;
#else
#  if defined(USE_ITHREADS) && defined(PERL_IMPLICIT_SYS)
    dSP; dTARGET;
    Pid_t childpid;

    EXTEND(SP, 1);
    PERL_FLUSHALL_FOR_CHILD;
    childpid = PerlProc_fork();
    if (childpid == -1)
        RETSETUNDEF;
    PUSHi(childpid);
    RETURN;
#  else
    DIE(aTHX_ PL_no_func, "fork");
#  endif
#endif
}

PP(pp_wait)
{
#if (!defined(DOSISH) || defined(OS2) || defined(WIN32)) && !defined(MACOS_TRADITIONAL)
    dSP; dTARGET;
    Pid_t childpid;
    int argflags;

    if (PL_signals & PERL_SIGNALS_UNSAFE_FLAG)
        childpid = wait4pid(-1, &argflags, 0);
    else {
        while ((childpid = wait4pid(-1, &argflags, 0)) == -1 &&
               errno == EINTR) {
          PERL_ASYNC_CHECK();
        }
    }
#  if defined(USE_ITHREADS) && defined(PERL_IMPLICIT_SYS)
    /* 0 and -1 are both error returns (the former applies to WNOHANG case) */
    STATUS_NATIVE_SET((childpid && childpid != -1) ? argflags : -1);
#  else
    STATUS_NATIVE_SET((childpid > 0) ? argflags : -1);
#  endif
    XPUSHi(childpid);
    RETURN;
#else
    DIE(aTHX_ PL_no_func, "wait");
#endif
}

PP(pp_waitpid)
{
#if (!defined(DOSISH) || defined(OS2) || defined(WIN32)) && !defined(MACOS_TRADITIONAL)
    dSP; dTARGET;
    Pid_t pid;
    Pid_t result;
    int optype;
    int argflags;

    optype = POPi;
    pid = TOPi;
    if (PL_signals & PERL_SIGNALS_UNSAFE_FLAG)
        result = wait4pid(pid, &argflags, optype);
    else {
        while ((result = wait4pid(pid, &argflags, optype)) == -1 &&
               errno == EINTR) {
          PERL_ASYNC_CHECK();
        }
    }
#  if defined(USE_ITHREADS) && defined(PERL_IMPLICIT_SYS)
    /* 0 and -1 are both error returns (the former applies to WNOHANG case) */
    STATUS_NATIVE_SET((result && result != -1) ? argflags : -1);
#  else
    STATUS_NATIVE_SET((result > 0) ? argflags : -1);
#  endif
    SETi(result);
    RETURN;
#else
    DIE(aTHX_ PL_no_func, "waitpid");
#endif
}

PP(pp_system)
{
    dSP; dMARK; dORIGMARK; dTARGET;
    I32 value;
    STRLEN n_a;
    int result;
    I32 did_pipes = 0;

    if (PL_tainting) {
        TAINT_ENV();
        while (++MARK <= SP) {
            (void)SvPV_nolen(*MARK);      /* stringify for taint check */
            if (PL_tainted)
                break;
        }
        MARK = ORIGMARK;
        TAINT_PROPER("system");
    }
    PERL_FLUSHALL_FOR_CHILD;
#if (defined(HAS_FORK) || defined(AMIGAOS)) && !defined(VMS) && !defined(OS2) || defined(PERL_MICRO)
    {
        Pid_t childpid;
        int pp[2];

        if (PerlProc_pipe(pp) >= 0)
            did_pipes = 1;
        while ((childpid = PerlProc_fork()) == -1) {
            if (errno != EAGAIN) {
                value = -1;
                SP = ORIGMARK;
                PUSHi(value);
                if (did_pipes) {
                    PerlLIO_close(pp[0]);
                    PerlLIO_close(pp[1]);
                }
                RETURN;
            }
            sleep(5);
        }
        if (childpid > 0) {
            Sigsave_t ihand,qhand; /* place to save signals during system() */
            int status;

            if (did_pipes)
                PerlLIO_close(pp[1]);
#ifndef PERL_MICRO
            rsignal_save(SIGINT, SIG_IGN, &ihand);
            rsignal_save(SIGQUIT, SIG_IGN, &qhand);
#endif
            do {
                result = wait4pid(childpid, &status, 0);
            } while (result == -1 && errno == EINTR);
#ifndef PERL_MICRO
            (void)rsignal_restore(SIGINT, &ihand);
            (void)rsignal_restore(SIGQUIT, &qhand);
#endif
            STATUS_NATIVE_SET(result == -1 ? -1 : status);
            do_execfree();      /* free any memory child malloced on fork */
            SP = ORIGMARK;
            if (did_pipes) {
                int errkid;
                int n = 0, n1;

                while (n < sizeof(int)) {
                    n1 = PerlLIO_read(pp[0],
                                      (void*)(((char*)&errkid)+n),
                                      (sizeof(int)) - n);
                    if (n1 <= 0)
                        break;
                    n += n1;
                }
                PerlLIO_close(pp[0]);
                if (n) {                        /* Error */
                    if (n != sizeof(int))
                        DIE(aTHX_ "panic: kid popen errno read");
                    errno = errkid;             /* Propagate errno from kid */
                    STATUS_CURRENT = -1;
                }
            }
            PUSHi(STATUS_CURRENT);
            RETURN;
        }
        if (did_pipes) {
            PerlLIO_close(pp[0]);
#if defined(HAS_FCNTL) && defined(F_SETFD)
            fcntl(pp[1], F_SETFD, FD_CLOEXEC);
#endif
        }
        if (PL_op->op_flags & OPf_STACKED) {
            SV *really = *++MARK;
            value = (I32)do_aexec5(really, MARK, SP, pp[1], did_pipes);
        }
        else if (SP - MARK != 1)
            value = (I32)do_aexec5(Nullsv, MARK, SP, pp[1], did_pipes);
        else {
            value = (I32)do_exec3(SvPVx(sv_mortalcopy(*SP), n_a), pp[1], did_pipes);
        }
        PerlProc__exit(-1);
    }
#else /* ! FORK or VMS or OS/2 */
    PL_statusvalue = 0;
    result = 0;
    if (PL_op->op_flags & OPf_STACKED) {
        SV *really = *++MARK;
#  if defined(WIN32) || defined(OS2)
        value = (I32)do_aspawn(really, MARK, SP);
#  else
        value = (I32)do_aspawn(really, (void **)MARK, (void **)SP);
#  endif
    }
    else if (SP - MARK != 1) {
#  if defined(WIN32) || defined(OS2)
        value = (I32)do_aspawn(Nullsv, MARK, SP);
#  else
        value = (I32)do_aspawn(Nullsv, (void **)MARK, (void **)SP);
#  endif
    }
    else {
        value = (I32)do_spawn(SvPVx(sv_mortalcopy(*SP), n_a));
    }
    if (PL_statusvalue == -1)   /* hint that value must be returned as is */
        result = 1;
    STATUS_NATIVE_SET(value);
    do_execfree();
    SP = ORIGMARK;
    PUSHi(result ? value : STATUS_CURRENT);
#endif /* !FORK or VMS */
    RETURN;
}

PP(pp_exec)
{
    dSP; dMARK; dORIGMARK; dTARGET;
    I32 value;
    STRLEN n_a;

    if (PL_tainting) {
        TAINT_ENV();
        while (++MARK <= SP) {
            (void)SvPV_nolen(*MARK);      /* stringify for taint check */
            if (PL_tainted)
                break;
        }
        MARK = ORIGMARK;
        TAINT_PROPER("exec");
    }
    PERL_FLUSHALL_FOR_CHILD;
    if (PL_op->op_flags & OPf_STACKED) {
        SV *really = *++MARK;
        value = (I32)do_aexec(really, MARK, SP);
    }
    else if (SP - MARK != 1)
#ifdef VMS
        value = (I32)vms_do_aexec(Nullsv, MARK, SP);
#else
#  ifdef __OPEN_VM
        {
           (void ) do_aspawn(Nullsv, MARK, SP);
           value = 0;
        }
#  else
        value = (I32)do_aexec(Nullsv, MARK, SP);
#  endif
#endif
    else {
#ifdef VMS
        value = (I32)vms_do_exec(SvPVx(sv_mortalcopy(*SP), n_a));
#else
#  ifdef __OPEN_VM
        (void) do_spawn(SvPVx(sv_mortalcopy(*SP), n_a));
        value = 0;
#  else
        value = (I32)do_exec(SvPVx(sv_mortalcopy(*SP), n_a));
#  endif
#endif
    }

    SP = ORIGMARK;
    PUSHi(value);
    RETURN;
}

PP(pp_kill)
{
#ifdef HAS_KILL
    dSP; dMARK; dTARGET;
    I32 value;
    value = (I32)apply(PL_op->op_type, MARK, SP);
    SP = MARK;
    PUSHi(value);
    RETURN;
#else
    DIE(aTHX_ PL_no_func, "kill");
#endif
}

PP(pp_getppid)
{
#ifdef HAS_GETPPID
    dSP; dTARGET;
#   ifdef THREADS_HAVE_PIDS
    XPUSHi( PL_ppid );
#   else
    XPUSHi( getppid() );
#   endif
    RETURN;
#else
    DIE(aTHX_ PL_no_func, "getppid");
#endif
}

PP(pp_getpgrp)
{
#ifdef HAS_GETPGRP
    dSP; dTARGET;
    Pid_t pid;
    Pid_t pgrp;

    if (MAXARG < 1)
        pid = 0;
    else
        pid = SvIVx(POPs);
#ifdef BSD_GETPGRP
    pgrp = (I32)BSD_GETPGRP(pid);
#else
    if (pid != 0 && pid != PerlProc_getpid())
        DIE(aTHX_ "POSIX getpgrp can't take an argument");
    pgrp = getpgrp();
#endif
    XPUSHi(pgrp);
    RETURN;
#else
    DIE(aTHX_ PL_no_func, "getpgrp()");
#endif
}

PP(pp_setpgrp)
{
#ifdef HAS_SETPGRP
    dSP; dTARGET;
    Pid_t pgrp;
    Pid_t pid;
    if (MAXARG < 2) {
        pgrp = 0;
        pid = 0;
    }
    else {
        pgrp = POPi;
        pid = TOPi;
    }

    TAINT_PROPER("setpgrp");
#ifdef BSD_SETPGRP
    SETi( BSD_SETPGRP(pid, pgrp) >= 0 );
#else
    if ((pgrp != 0 && pgrp != PerlProc_getpid())
        || (pid != 0 && pid != PerlProc_getpid()))
    {
        DIE(aTHX_ "setpgrp can't take arguments");
    }
    SETi( setpgrp() >= 0 );
#endif /* USE_BSDPGRP */
    RETURN;
#else
    DIE(aTHX_ PL_no_func, "setpgrp()");
#endif
}

PP(pp_getpriority)
{
#ifdef HAS_GETPRIORITY
    dSP; dTARGET;
    int who = POPi;
    int which = TOPi;
    SETi( getpriority(which, who) );
    RETURN;
#else
    DIE(aTHX_ PL_no_func, "getpriority()");
#endif
}

PP(pp_setpriority)
{
#ifdef HAS_SETPRIORITY
    dSP; dTARGET;
    int niceval = POPi;
    int who = POPi;
    int which = TOPi;
    TAINT_PROPER("setpriority");
    SETi( setpriority(which, who, niceval) >= 0 );
    RETURN;
#else
    DIE(aTHX_ PL_no_func, "setpriority()");
#endif
}

/* Time calls. */

PP(pp_time)
{
    dSP; dTARGET;
#ifdef BIG_TIME
    XPUSHn( time(Null(Time_t*)) );
#else
    XPUSHi( time(Null(Time_t*)) );
#endif
    RETURN;
}

PP(pp_tms)
{
#ifdef HAS_TIMES
    dSP;
    EXTEND(SP, 4);
#ifndef VMS
    (void)PerlProc_times(&PL_timesbuf);
#else
    (void)PerlProc_times((tbuffer_t *)&PL_timesbuf);  /* time.h uses different name for */
                                                   /* struct tms, though same data   */
                                                   /* is returned.                   */
#endif

    PUSHs(sv_2mortal(newSVnv(((NV)PL_timesbuf.tms_utime)/(NV)PL_clocktick)));
    if (GIMME == G_ARRAY) {
        PUSHs(sv_2mortal(newSVnv(((NV)PL_timesbuf.tms_stime)/(NV)PL_clocktick)));
        PUSHs(sv_2mortal(newSVnv(((NV)PL_timesbuf.tms_cutime)/(NV)PL_clocktick)));
        PUSHs(sv_2mortal(newSVnv(((NV)PL_timesbuf.tms_cstime)/(NV)PL_clocktick)));
    }
    RETURN;
#else
#   ifdef PERL_MICRO
    dSP;
    PUSHs(sv_2mortal(newSVnv((NV)0.0)));
    EXTEND(SP, 4);
    if (GIMME == G_ARRAY) {
         PUSHs(sv_2mortal(newSVnv((NV)0.0)));
         PUSHs(sv_2mortal(newSVnv((NV)0.0)));
         PUSHs(sv_2mortal(newSVnv((NV)0.0)));
    }
    RETURN;
#   else
    DIE(aTHX_ "times not implemented");
#   endif
#endif /* HAS_TIMES */
}

PP(pp_localtime)
{
    return pp_gmtime();
}

PP(pp_gmtime)
{
    dSP;
    Time_t when;
    struct tm *tmbuf;
    static char *dayname[] = {"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"};
    static char *monname[] = {"Jan", "Feb", "Mar", "Apr", "May", "Jun",
                              "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"};

    if (MAXARG < 1)
        (void)time(&when);
    else
#ifdef BIG_TIME
        when = (Time_t)SvNVx(POPs);
#else
        when = (Time_t)SvIVx(POPs);
#endif

    if (PL_op->op_type == OP_LOCALTIME)
        tmbuf = localtime(&when);
    else
        tmbuf = gmtime(&when);

    if (GIMME != G_ARRAY) {
        SV *tsv;
        EXTEND(SP, 1);
        EXTEND_MORTAL(1);
        if (!tmbuf)
            RETPUSHUNDEF;
        tsv = Perl_newSVpvf(aTHX_ "%s %s %2d %02d:%02d:%02d %d",
                            dayname[tmbuf->tm_wday],
                            monname[tmbuf->tm_mon],
                            tmbuf->tm_mday,
                            tmbuf->tm_hour,
                            tmbuf->tm_min,
                            tmbuf->tm_sec,
                            tmbuf->tm_year + 1900);
        PUSHs(sv_2mortal(tsv));
    }
    else if (tmbuf) {
        EXTEND(SP, 9);
        EXTEND_MORTAL(9);
        PUSHs(sv_2mortal(newSViv(tmbuf->tm_sec)));
        PUSHs(sv_2mortal(newSViv(tmbuf->tm_min)));
        PUSHs(sv_2mortal(newSViv(tmbuf->tm_hour)));
        PUSHs(sv_2mortal(newSViv(tmbuf->tm_mday)));
        PUSHs(sv_2mortal(newSViv(tmbuf->tm_mon)));
        PUSHs(sv_2mortal(newSViv(tmbuf->tm_year)));
        PUSHs(sv_2mortal(newSViv(tmbuf->tm_wday)));
        PUSHs(sv_2mortal(newSViv(tmbuf->tm_yday)));
        PUSHs(sv_2mortal(newSViv(tmbuf->tm_isdst)));
    }
    RETURN;
}

PP(pp_alarm)
{
#ifdef HAS_ALARM
    dSP; dTARGET;
    int anum;
    anum = POPi;
    anum = alarm((unsigned int)anum);
    EXTEND(SP, 1);
    if (anum < 0)
        RETPUSHUNDEF;
    PUSHi(anum);
    RETURN;
#else
    DIE(aTHX_ PL_no_func, "alarm");
#endif
}

PP(pp_sleep)
{
    dSP; dTARGET;
    I32 duration;
    Time_t lasttime;
    Time_t when;

    (void)time(&lasttime);
    if (MAXARG < 1)
        PerlProc_pause();
    else {
        duration = POPi;
        PerlProc_sleep((unsigned int)duration);
    }
    (void)time(&when);
    XPUSHi(when - lasttime);
    RETURN;
}

/* Shared memory. */

PP(pp_shmget)
{
    return pp_semget();
}

PP(pp_shmctl)
{
    return pp_semctl();
}

PP(pp_shmread)
{
    return pp_shmwrite();
}

PP(pp_shmwrite)
{
#if defined(HAS_MSG) || defined(HAS_SEM) || defined(HAS_SHM)
    dSP; dMARK; dTARGET;
    I32 value = (I32)(do_shmio(PL_op->op_type, MARK, SP) >= 0);
    SP = MARK;
    PUSHi(value);
    RETURN;
#else
    return pp_semget();
#endif
}

/* Message passing. */

PP(pp_msgget)
{
    return pp_semget();
}

PP(pp_msgctl)
{
    return pp_semctl();
}

PP(pp_msgsnd)
{
#if defined(HAS_MSG) || defined(HAS_SEM) || defined(HAS_SHM)
    dSP; dMARK; dTARGET;
    I32 value = (I32)(do_msgsnd(MARK, SP) >= 0);
    SP = MARK;
    PUSHi(value);
    RETURN;
#else
    return pp_semget();
#endif
}

PP(pp_msgrcv)
{
#if defined(HAS_MSG) || defined(HAS_SEM) || defined(HAS_SHM)
    dSP; dMARK; dTARGET;
    I32 value = (I32)(do_msgrcv(MARK, SP) >= 0);
    SP = MARK;
    PUSHi(value);
    RETURN;
#else
    return pp_semget();
#endif
}

/* Semaphores. */

PP(pp_semget)
{
#if defined(HAS_MSG) || defined(HAS_SEM) || defined(HAS_SHM)
    dSP; dMARK; dTARGET;
    int anum = do_ipcget(PL_op->op_type, MARK, SP);
    SP = MARK;
    if (anum == -1)
        RETPUSHUNDEF;
    PUSHi(anum);
    RETURN;
#else
    DIE(aTHX_ "System V IPC is not implemented on this machine");
#endif
}

PP(pp_semctl)
{
#if defined(HAS_MSG) || defined(HAS_SEM) || defined(HAS_SHM)
    dSP; dMARK; dTARGET;
    int anum = do_ipcctl(PL_op->op_type, MARK, SP);
    SP = MARK;
    if (anum == -1)
        RETSETUNDEF;
    if (anum != 0) {
        PUSHi(anum);
    }
    else {
        PUSHp(zero_but_true, ZBTLEN);
    }
    RETURN;
#else
    return pp_semget();
#endif
}

PP(pp_semop)
{
#if defined(HAS_MSG) || defined(HAS_SEM) || defined(HAS_SHM)
    dSP; dMARK; dTARGET;
    I32 value = (I32)(do_semop(MARK, SP) >= 0);
    SP = MARK;
    PUSHi(value);
    RETURN;
#else
    return pp_semget();
#endif
}

/* Get system info. */

PP(pp_ghbyname)
{
#ifdef HAS_GETHOSTBYNAME
    return pp_ghostent();
#else
    DIE(aTHX_ PL_no_sock_func, "gethostbyname");
#endif
}

PP(pp_ghbyaddr)
{
#ifdef HAS_GETHOSTBYADDR
    return pp_ghostent();
#else
    DIE(aTHX_ PL_no_sock_func, "gethostbyaddr");
#endif
}

PP(pp_ghostent)
{
#if defined(HAS_GETHOSTBYNAME) || defined(HAS_GETHOSTBYADDR) || defined(HAS_GETHOSTENT)
    dSP;
    I32 which = PL_op->op_type;
    register char **elem;
    register SV *sv;
#ifndef HAS_GETHOST_PROTOS /* XXX Do we need individual probes? */
    struct hostent *gethostbyaddr(Netdb_host_t, Netdb_hlen_t, int);
    struct hostent *gethostbyname(Netdb_name_t);
    struct hostent *gethostent(void);
#endif
    struct hostent *hent;
    unsigned long len;
    STRLEN n_a;

    EXTEND(SP, 10);
    if (which == OP_GHBYNAME) {
#ifdef HAS_GETHOSTBYNAME
        char* name = POPpbytex;
        hent = PerlSock_gethostbyname(name);
#else
        DIE(aTHX_ PL_no_sock_func, "gethostbyname");
#endif
    }
    else if (which == OP_GHBYADDR) {
#ifdef HAS_GETHOSTBYADDR
        int addrtype = POPi;
        SV *addrsv = POPs;
        STRLEN addrlen;
        Netdb_host_t addr = (Netdb_host_t) SvPVbyte(addrsv, addrlen);

        hent = PerlSock_gethostbyaddr(addr, (Netdb_hlen_t) addrlen, addrtype);
#else
        DIE(aTHX_ PL_no_sock_func, "gethostbyaddr");
#endif
    }
    else
#ifdef HAS_GETHOSTENT
        hent = PerlSock_gethostent();
#else
        DIE(aTHX_ PL_no_sock_func, "gethostent");
#endif

#ifdef HOST_NOT_FOUND
        if (!hent) {
#ifdef USE_REENTRANT_API
#   ifdef USE_GETHOSTENT_ERRNO
            h_errno = PL_reentrant_buffer->_gethostent_errno;
#   endif
#endif
            STATUS_NATIVE_SET(h_errno);
        }
#endif

    if (GIMME != G_ARRAY) {
        PUSHs(sv = sv_newmortal());
        if (hent) {
            if (which == OP_GHBYNAME) {
                if (hent->h_addr)
                    sv_setpvn(sv, hent->h_addr, hent->h_length);
            }
            else
                sv_setpv(sv, (char*)hent->h_name);
        }
        RETURN;
    }

    if (hent) {
        PUSHs(sv = sv_mortalcopy(&PL_sv_no));
        sv_setpv(sv, (char*)hent->h_name);
        PUSHs(sv = sv_mortalcopy(&PL_sv_no));
        for (elem = hent->h_aliases; elem && *elem; elem++) {
            sv_catpv(sv, *elem);
            if (elem[1])
                sv_catpvn(sv, " ", 1);
        }
        PUSHs(sv = sv_mortalcopy(&PL_sv_no));
        sv_setiv(sv, (IV)hent->h_addrtype);
        PUSHs(sv = sv_mortalcopy(&PL_sv_no));
        len = hent->h_length;
        sv_setiv(sv, (IV)len);
#ifdef h_addr
        for (elem = hent->h_addr_list; elem && *elem; elem++) {
            XPUSHs(sv = sv_mortalcopy(&PL_sv_no));
            sv_setpvn(sv, *elem, len);
        }
#else
        PUSHs(sv = sv_mortalcopy(&PL_sv_no));
        if (hent->h_addr)
            sv_setpvn(sv, hent->h_addr, len);
#endif /* h_addr */
    }
    RETURN;
#else
    DIE(aTHX_ PL_no_sock_func, "gethostent");
#endif
}

PP(pp_gnbyname)
{
#ifdef HAS_GETNETBYNAME
    return pp_gnetent();
#else
    DIE(aTHX_ PL_no_sock_func, "getnetbyname");
#endif
}

PP(pp_gnbyaddr)
{
#ifdef HAS_GETNETBYADDR
    return pp_gnetent();
#else
    DIE(aTHX_ PL_no_sock_func, "getnetbyaddr");
#endif
}

PP(pp_gnetent)
{
#if defined(HAS_GETNETBYNAME) || defined(HAS_GETNETBYADDR) || defined(HAS_GETNETENT)
    dSP;
    I32 which = PL_op->op_type;
    register char **elem;
    register SV *sv;
#ifndef HAS_GETNET_PROTOS /* XXX Do we need individual probes? */
    struct netent *getnetbyaddr(Netdb_net_t, int);
    struct netent *getnetbyname(Netdb_name_t);
    struct netent *getnetent(void);
#endif
    struct netent *nent;
    STRLEN n_a;

    if (which == OP_GNBYNAME){
#ifdef HAS_GETNETBYNAME
        char *name = POPpbytex;
        nent = PerlSock_getnetbyname(name);
#else
        DIE(aTHX_ PL_no_sock_func, "getnetbyname");
#endif
    }
    else if (which == OP_GNBYADDR) {
#ifdef HAS_GETNETBYADDR
        int addrtype = POPi;
        Netdb_net_t addr = (Netdb_net_t) (U32)POPu;
        nent = PerlSock_getnetbyaddr(addr, addrtype);
#else
        DIE(aTHX_ PL_no_sock_func, "getnetbyaddr");
#endif
    }
    else
#ifdef HAS_GETNETENT
        nent = PerlSock_getnetent();
#else
        DIE(aTHX_ PL_no_sock_func, "getnetent");
#endif

#ifdef HOST_NOT_FOUND
        if (!nent) {
#ifdef USE_REENTRANT_API
#   ifdef USE_GETNETENT_ERRNO
             h_errno = PL_reentrant_buffer->_getnetent_errno;
#   endif
#endif
            STATUS_NATIVE_SET(h_errno);
        }
#endif

    EXTEND(SP, 4);
    if (GIMME != G_ARRAY) {
        PUSHs(sv = sv_newmortal());
        if (nent) {
            if (which == OP_GNBYNAME)
                sv_setiv(sv, (IV)nent->n_net);
            else
                sv_setpv(sv, nent->n_name);
        }
        RETURN;
    }

    if (nent) {
        PUSHs(sv = sv_mortalcopy(&PL_sv_no));
        sv_setpv(sv, nent->n_name);
        PUSHs(sv = sv_mortalcopy(&PL_sv_no));
        for (elem = nent->n_aliases; elem && *elem; elem++) {
            sv_catpv(sv, *elem);
            if (elem[1])
                sv_catpvn(sv, " ", 1);
        }
        PUSHs(sv = sv_mortalcopy(&PL_sv_no));
        sv_setiv(sv, (IV)nent->n_addrtype);
        PUSHs(sv = sv_mortalcopy(&PL_sv_no));
        sv_setiv(sv, (IV)nent->n_net);
    }

    RETURN;
#else
    DIE(aTHX_ PL_no_sock_func, "getnetent");
#endif
}

PP(pp_gpbyname)
{
#ifdef HAS_GETPROTOBYNAME
    return pp_gprotoent();
#else
    DIE(aTHX_ PL_no_sock_func, "getprotobyname");
#endif
}

PP(pp_gpbynumber)
{
#ifdef HAS_GETPROTOBYNUMBER
    return pp_gprotoent();
#else
    DIE(aTHX_ PL_no_sock_func, "getprotobynumber");
#endif
}

PP(pp_gprotoent)
{
#if defined(HAS_GETPROTOBYNAME) || defined(HAS_GETPROTOBYNUMBER) || defined(HAS_GETPROTOENT)
    dSP;
    I32 which = PL_op->op_type;
    register char **elem;
    register SV *sv;
#ifndef HAS_GETPROTO_PROTOS /* XXX Do we need individual probes? */
    struct protoent *getprotobyname(Netdb_name_t);
    struct protoent *getprotobynumber(int);
    struct protoent *getprotoent(void);
#endif
    struct protoent *pent;
    STRLEN n_a;

    if (which == OP_GPBYNAME) {
#ifdef HAS_GETPROTOBYNAME
        char* name = POPpbytex;
        pent = PerlSock_getprotobyname(name);
#else
        DIE(aTHX_ PL_no_sock_func, "getprotobyname");
#endif
    }
    else if (which == OP_GPBYNUMBER) {
#ifdef HAS_GETPROTOBYNUMBER
        int number = POPi;
        pent = PerlSock_getprotobynumber(number);
#else
        DIE(aTHX_ PL_no_sock_func, "getprotobynumber");
#endif
    }
    else
#ifdef HAS_GETPROTOENT
        pent = PerlSock_getprotoent();
#else
        DIE(aTHX_ PL_no_sock_func, "getprotoent");
#endif

    EXTEND(SP, 3);
    if (GIMME != G_ARRAY) {
        PUSHs(sv = sv_newmortal());
        if (pent) {
            if (which == OP_GPBYNAME)
                sv_setiv(sv, (IV)pent->p_proto);
            else
                sv_setpv(sv, pent->p_name);
        }
        RETURN;
    }

    if (pent) {
        PUSHs(sv = sv_mortalcopy(&PL_sv_no));
        sv_setpv(sv, pent->p_name);
        PUSHs(sv = sv_mortalcopy(&PL_sv_no));
        for (elem = pent->p_aliases; elem && *elem; elem++) {
            sv_catpv(sv, *elem);
            if (elem[1])
                sv_catpvn(sv, " ", 1);
        }
        PUSHs(sv = sv_mortalcopy(&PL_sv_no));
        sv_setiv(sv, (IV)pent->p_proto);
    }

    RETURN;
#else
    DIE(aTHX_ PL_no_sock_func, "getprotoent");
#endif
}

PP(pp_gsbyname)
{
#ifdef HAS_GETSERVBYNAME
    return pp_gservent();
#else
    DIE(aTHX_ PL_no_sock_func, "getservbyname");
#endif
}

PP(pp_gsbyport)
{
#ifdef HAS_GETSERVBYPORT
    return pp_gservent();
#else
    DIE(aTHX_ PL_no_sock_func, "getservbyport");
#endif
}

PP(pp_gservent)
{
#if defined(HAS_GETSERVBYNAME) || defined(HAS_GETSERVBYPORT) || defined(HAS_GETSERVENT)
    dSP;
    I32 which = PL_op->op_type;
    register char **elem;
    register SV *sv;
#ifndef HAS_GETSERV_PROTOS /* XXX Do we need individual probes? */
    struct servent *getservbyname(Netdb_name_t, Netdb_name_t);
    struct servent *getservbyport(int, Netdb_name_t);
    struct servent *getservent(void);
#endif
    struct servent *sent;
    STRLEN n_a;

    if (which == OP_GSBYNAME) {
#ifdef HAS_GETSERVBYNAME
        char *proto = POPpbytex;
        char *name = POPpbytex;

        if (proto && !*proto)
            proto = Nullch;

        sent = PerlSock_getservbyname(name, proto);
#else
        DIE(aTHX_ PL_no_sock_func, "getservbyname");
#endif
    }
    else if (which == OP_GSBYPORT) {
#ifdef HAS_GETSERVBYPORT
        char *proto = POPpbytex;
        unsigned short port = (unsigned short)POPu;

        if (proto && !*proto)
            proto = Nullch;

#ifdef HAS_HTONS
        port = PerlSock_htons(port);
#endif
        sent = PerlSock_getservbyport(port, proto);
#else
        DIE(aTHX_ PL_no_sock_func, "getservbyport");
#endif
    }
    else
#ifdef HAS_GETSERVENT
        sent = PerlSock_getservent();
#else
        DIE(aTHX_ PL_no_sock_func, "getservent");
#endif

    EXTEND(SP, 4);
    if (GIMME != G_ARRAY) {
        PUSHs(sv = sv_newmortal());
        if (sent) {
            if (which == OP_GSBYNAME) {
#ifdef HAS_NTOHS
                sv_setiv(sv, (IV)PerlSock_ntohs(sent->s_port));
#else
                sv_setiv(sv, (IV)(sent->s_port));
#endif
            }
            else
                sv_setpv(sv, sent->s_name);
        }
        RETURN;
    }

    if (sent) {
        PUSHs(sv = sv_mortalcopy(&PL_sv_no));
        sv_setpv(sv, sent->s_name);
        PUSHs(sv = sv_mortalcopy(&PL_sv_no));
        for (elem = sent->s_aliases; elem && *elem; elem++) {
            sv_catpv(sv, *elem);
            if (elem[1])
                sv_catpvn(sv, " ", 1);
        }
        PUSHs(sv = sv_mortalcopy(&PL_sv_no));
#ifdef HAS_NTOHS
        sv_setiv(sv, (IV)PerlSock_ntohs(sent->s_port));
#else
        sv_setiv(sv, (IV)(sent->s_port));
#endif
        PUSHs(sv = sv_mortalcopy(&PL_sv_no));
        sv_setpv(sv, sent->s_proto);
    }

    RETURN;
#else
    DIE(aTHX_ PL_no_sock_func, "getservent");
#endif
}

PP(pp_shostent)
{
#ifdef HAS_SETHOSTENT
    dSP;
    PerlSock_sethostent(TOPi);
    RETSETYES;
#else
    DIE(aTHX_ PL_no_sock_func, "sethostent");
#endif
}

PP(pp_snetent)
{
#ifdef HAS_SETNETENT
    dSP;
    PerlSock_setnetent(TOPi);
    RETSETYES;
#else
    DIE(aTHX_ PL_no_sock_func, "setnetent");
#endif
}

PP(pp_sprotoent)
{
#ifdef HAS_SETPROTOENT
    dSP;
    PerlSock_setprotoent(TOPi);
    RETSETYES;
#else
    DIE(aTHX_ PL_no_sock_func, "setprotoent");
#endif
}

PP(pp_sservent)
{
#ifdef HAS_SETSERVENT
    dSP;
    PerlSock_setservent(TOPi);
    RETSETYES;
#else
    DIE(aTHX_ PL_no_sock_func, "setservent");
#endif
}

PP(pp_ehostent)
{
#ifdef HAS_ENDHOSTENT
    dSP;
    PerlSock_endhostent();
    EXTEND(SP,1);
    RETPUSHYES;
#else
    DIE(aTHX_ PL_no_sock_func, "endhostent");
#endif
}

PP(pp_enetent)
{
#ifdef HAS_ENDNETENT
    dSP;
    PerlSock_endnetent();
    EXTEND(SP,1);
    RETPUSHYES;
#else
    DIE(aTHX_ PL_no_sock_func, "endnetent");
#endif
}

PP(pp_eprotoent)
{
#ifdef HAS_ENDPROTOENT
    dSP;
    PerlSock_endprotoent();
    EXTEND(SP,1);
    RETPUSHYES;
#else
    DIE(aTHX_ PL_no_sock_func, "endprotoent");
#endif
}

PP(pp_eservent)
{
#ifdef HAS_ENDSERVENT
    dSP;
    PerlSock_endservent();
    EXTEND(SP,1);
    RETPUSHYES;
#else
    DIE(aTHX_ PL_no_sock_func, "endservent");
#endif
}

PP(pp_gpwnam)
{
#ifdef HAS_PASSWD
    return pp_gpwent();
#else
    DIE(aTHX_ PL_no_func, "getpwnam");
#endif
}

PP(pp_gpwuid)
{
#ifdef HAS_PASSWD
    return pp_gpwent();
#else
    DIE(aTHX_ PL_no_func, "getpwuid");
#endif
}

PP(pp_gpwent)
{
#ifdef HAS_PASSWD
    dSP;
    I32 which = PL_op->op_type;
    register SV *sv;
    STRLEN n_a;
    struct passwd *pwent  = NULL;
    /*
     * We currently support only the SysV getsp* shadow password interface.
     * The interface is declared in <shadow.h> and often one needs to link
     * with -lsecurity or some such.
     * This interface is used at least by Solaris, HP-UX, IRIX, and Linux.
     * (and SCO?)
     *
     * AIX getpwnam() is clever enough to return the encrypted password
     * only if the caller (euid?) is root.
     *
     * There are at least three other shadow password APIs.  Many platforms
     * seem to contain more than one interface for accessing the shadow
     * password databases, possibly for compatibility reasons.
     * The getsp*() is by far he simplest one, the other two interfaces
     * are much more complicated, but also very similar to each other.
     *
     * <sys/types.h>
     * <sys/security.h>
     * <prot.h>
     * struct pr_passwd *getprpw*();
     * The password is in
     * char getprpw*(...).ufld.fd_encrypt[]
     * Mention HAS_GETPRPWNAM here so that Configure probes for it.
     *
     * <sys/types.h>
     * <sys/security.h>
     * <prot.h>
     * struct es_passwd *getespw*();
     * The password is in
     * char *(getespw*(...).ufld.fd_encrypt)
     * Mention HAS_GETESPWNAM here so that Configure probes for it.
     *
     * <userpw.h> (AIX)
     * struct userpw *getuserpw();
     * The password is in
     * char *(getuserpw(...)).spw_upw_passwd
     * (but the de facto standard getpwnam() should work okay)
     *
     * Mention I_PROT here so that Configure probes for it.
     *
     * In HP-UX for getprpw*() the manual page claims that one should include
     * <hpsecurity.h> instead of <sys/security.h>, but that is not needed
     * if one includes <shadow.h> as that includes <hpsecurity.h>,
     * and pp_sys.c already includes <shadow.h> if there is such.
     *
     * Note that <sys/security.h> is already probed for, but currently
     * it is only included in special cases.
     *
     * In Digital UNIX/Tru64 if using the getespw*() (which seems to be
     * be preferred interface, even though also the getprpw*() interface
     * is available) one needs to link with -lsecurity -ldb -laud -lm.
     * One also needs to call set_auth_parameters() in main() before
     * doing anything else, whether one is using getespw*() or getprpw*().
     *
     * Note that accessing the shadow databases can be magnitudes
     * slower than accessing the standard databases.
     *
     * --jhi
     */

#   if defined(__CYGWIN__) && defined(USE_REENTRANT_API)
    /* Cygwin 1.5.3-1 has buggy getpwnam_r() and getpwuid_r():
     * the pw_comment is left uninitialized. */
    PL_reentrant_buffer->_pwent_struct.pw_comment = NULL;
#   endif

    switch (which) {
    case OP_GPWNAM:
      {
        char* name = POPpbytex;
        pwent  = getpwnam(name);
      }
      break;
    case OP_GPWUID:
      {
        Uid_t uid = POPi;
        pwent = getpwuid(uid);
      }
        break;
    case OP_GPWENT:
#   ifdef HAS_GETPWENT
        pwent  = getpwent();
#ifdef POSIX_BC   /* In some cases pw_passwd has invalid addresses */
        if (pwent) pwent = getpwnam(pwent->pw_name);
#endif
#   else
        DIE(aTHX_ PL_no_func, "getpwent");
#   endif
        break;
    }

    EXTEND(SP, 10);
    if (GIMME != G_ARRAY) {
        PUSHs(sv = sv_newmortal());
        if (pwent) {
            if (which == OP_GPWNAM)
#   if Uid_t_sign <= 0
                sv_setiv(sv, (IV)pwent->pw_uid);
#   else
                sv_setuv(sv, (UV)pwent->pw_uid);
#   endif
            else
                sv_setpv(sv, pwent->pw_name);
        }
        RETURN;
    }

    if (pwent) {
        PUSHs(sv = sv_mortalcopy(&PL_sv_no));
        sv_setpv(sv, pwent->pw_name);

        PUSHs(sv = sv_mortalcopy(&PL_sv_no));
        SvPOK_off(sv);
        /* If we have getspnam(), we try to dig up the shadow
         * password.  If we are underprivileged, the shadow
         * interface will set the errno to EACCES or similar,
         * and return a null pointer.  If this happens, we will
         * use the dummy password (usually "*" or "x") from the
         * standard password database.
         *
         * In theory we could skip the shadow call completely
         * if euid != 0 but in practice we cannot know which
         * security measures are guarding the shadow databases
         * on a random platform.
         *
         * Resist the urge to use additional shadow interfaces.
         * Divert the urge to writing an extension instead.
         *
         * --jhi */
        /* Some AIX setups falsely(?) detect some getspnam(), which
         * has a different API than the Solaris/IRIX one. */
#   if defined(HAS_GETSPNAM) && !defined(_AIX)
        {
            struct spwd *spwent;
            int saverrno; /* Save and restore errno so that
                           * underprivileged attempts seem
                           * to have never made the unsccessful
                           * attempt to retrieve the shadow password. */

            saverrno = errno;
            spwent = getspnam(pwent->pw_name);
            errno = saverrno;
            if (spwent && spwent->sp_pwdp)
                sv_setpv(sv, spwent->sp_pwdp);
        }
#   endif
#   ifdef PWPASSWD
        if (!SvPOK(sv)) /* Use the standard password, then. */
            sv_setpv(sv, pwent->pw_passwd);
#   endif

#   ifndef INCOMPLETE_TAINTS
        /* passwd is tainted because user himself can diddle with it.
         * admittedly not much and in a very limited way, but nevertheless. */
        SvTAINTED_on(sv);
#   endif

        PUSHs(sv = sv_mortalcopy(&PL_sv_no));
#   if Uid_t_sign <= 0
        sv_setiv(sv, (IV)pwent->pw_uid);
#   else
        sv_setuv(sv, (UV)pwent->pw_uid);
#   endif

        PUSHs(sv = sv_mortalcopy(&PL_sv_no));
#   if Uid_t_sign <= 0
        sv_setiv(sv, (IV)pwent->pw_gid);
#   else
        sv_setuv(sv, (UV)pwent->pw_gid);
#   endif
        /* pw_change, pw_quota, and pw_age are mutually exclusive--
         * because of the poor interface of the Perl getpw*(),
         * not because there's some standard/convention saying so.
         * A better interface would have been to return a hash,
         * but we are accursed by our history, alas. --jhi.  */
        PUSHs(sv = sv_mortalcopy(&PL_sv_no));
#   ifdef PWCHANGE
        sv_setiv(sv, (IV)pwent->pw_change);
#   else
#       ifdef PWQUOTA
        sv_setiv(sv, (IV)pwent->pw_quota);
#       else
#           ifdef PWAGE
        sv_setpv(sv, pwent->pw_age);
#           endif
#       endif
#   endif

        /* pw_class and pw_comment are mutually exclusive--.
         * see the above note for pw_change, pw_quota, and pw_age. */
        PUSHs(sv = sv_mortalcopy(&PL_sv_no));
#   ifdef PWCLASS
        sv_setpv(sv, pwent->pw_class);
#   else
#       ifdef PWCOMMENT
        sv_setpv(sv, pwent->pw_comment);
#       endif
#   endif

        PUSHs(sv = sv_mortalcopy(&PL_sv_no));
#   ifdef PWGECOS
        sv_setpv(sv, pwent->pw_gecos);
#   endif
#   ifndef INCOMPLETE_TAINTS
        /* pw_gecos is tainted because user himself can diddle with it. */
        SvTAINTED_on(sv);
#   endif

        PUSHs(sv = sv_mortalcopy(&PL_sv_no));
        sv_setpv(sv, pwent->pw_dir);

        PUSHs(sv = sv_mortalcopy(&PL_sv_no));
        sv_setpv(sv, pwent->pw_shell);
#   ifndef INCOMPLETE_TAINTS
        /* pw_shell is tainted because user himself can diddle with it. */
        SvTAINTED_on(sv);
#   endif

#   ifdef PWEXPIRE
        PUSHs(sv = sv_mortalcopy(&PL_sv_no));
        sv_setiv(sv, (IV)pwent->pw_expire);
#   endif
    }
    RETURN;
#else
    DIE(aTHX_ PL_no_func, "getpwent");
#endif
}

PP(pp_spwent)
{
#if defined(HAS_PASSWD) && defined(HAS_SETPWENT)
    dSP;
    setpwent();
    RETPUSHYES;
#else
    DIE(aTHX_ PL_no_func, "setpwent");
#endif
}

PP(pp_epwent)
{
#if defined(HAS_PASSWD) && defined(HAS_ENDPWENT)
    dSP;
    endpwent();
    RETPUSHYES;
#else
    DIE(aTHX_ PL_no_func, "endpwent");
#endif
}

PP(pp_ggrnam)
{
#ifdef HAS_GROUP
    return pp_ggrent();
#else
    DIE(aTHX_ PL_no_func, "getgrnam");
#endif
}

PP(pp_ggrgid)
{
#ifdef HAS_GROUP
    return pp_ggrent();
#else
    DIE(aTHX_ PL_no_func, "getgrgid");
#endif
}

PP(pp_ggrent)
{
#ifdef HAS_GROUP
    dSP;
    I32 which = PL_op->op_type;
    register char **elem;
    register SV *sv;
    struct group *grent;
    STRLEN n_a;

    if (which == OP_GGRNAM) {
        char* name = POPpbytex;
        grent = (struct group *)getgrnam(name);
    }
    else if (which == OP_GGRGID) {
        Gid_t gid = POPi;
        grent = (struct group *)getgrgid(gid);
    }
    else
#ifdef HAS_GETGRENT
        grent = (struct group *)getgrent();
#else
        DIE(aTHX_ PL_no_func, "getgrent");
#endif

    EXTEND(SP, 4);
    if (GIMME != G_ARRAY) {
        PUSHs(sv = sv_newmortal());
        if (grent) {
            if (which == OP_GGRNAM)
                sv_setiv(sv, (IV)grent->gr_gid);
            else
                sv_setpv(sv, grent->gr_name);
        }
        RETURN;
    }

    if (grent) {
        PUSHs(sv = sv_mortalcopy(&PL_sv_no));
        sv_setpv(sv, grent->gr_name);

        PUSHs(sv = sv_mortalcopy(&PL_sv_no));
#ifdef GRPASSWD
        sv_setpv(sv, grent->gr_passwd);
#endif

        PUSHs(sv = sv_mortalcopy(&PL_sv_no));
        sv_setiv(sv, (IV)grent->gr_gid);

#if !(defined(_CRAYMPP) && defined(USE_REENTRANT_API))
        PUSHs(sv = sv_mortalcopy(&PL_sv_no));
        /* In UNICOS/mk (_CRAYMPP) the multithreading
         * versions (getgrnam_r, getgrgid_r)
         * seem to return an illegal pointer
         * as the group members list, gr_mem.
         * getgrent() doesn't even have a _r version
         * but the gr_mem is poisonous anyway.
         * So yes, you cannot get the list of group
         * members if building multithreaded in UNICOS/mk. */
        for (elem = grent->gr_mem; elem && *elem; elem++) {
            sv_catpv(sv, *elem);
            if (elem[1])
                sv_catpvn(sv, " ", 1);
        }
#endif
    }

    RETURN;
#else
    DIE(aTHX_ PL_no_func, "getgrent");
#endif
}

PP(pp_sgrent)
{
#if defined(HAS_GROUP) && defined(HAS_SETGRENT)
    dSP;
    setgrent();
    RETPUSHYES;
#else
    DIE(aTHX_ PL_no_func, "setgrent");
#endif
}

PP(pp_egrent)
{
#if defined(HAS_GROUP) && defined(HAS_ENDGRENT)
    dSP;
    endgrent();
    RETPUSHYES;
#else
    DIE(aTHX_ PL_no_func, "endgrent");
#endif
}

PP(pp_getlogin)
{
#ifdef HAS_GETLOGIN
    dSP; dTARGET;
    char *tmps;
    EXTEND(SP, 1);
    if (!(tmps = PerlProc_getlogin()))
        RETPUSHUNDEF;
    PUSHp(tmps, strlen(tmps));
    RETURN;
#else
    DIE(aTHX_ PL_no_func, "getlogin");
#endif
}

/* Miscellaneous. */

PP(pp_syscall)
{
#ifdef HAS_SYSCALL
    dSP; dMARK; dORIGMARK; dTARGET;
    register I32 items = SP - MARK;
    unsigned long a[20];
    register I32 i = 0;
    I32 retval = -1;
    STRLEN n_a;

    if (PL_tainting) {
        while (++MARK <= SP) {
            if (SvTAINTED(*MARK)) {
                TAINT;
                break;
            }
        }
        MARK = ORIGMARK;
        TAINT_PROPER("syscall");
    }

    /* This probably won't work on machines where sizeof(long) != sizeof(int)
     * or where sizeof(long) != sizeof(char*).  But such machines will
     * not likely have syscall implemented either, so who cares?
     */
    while (++MARK <= SP) {
        if (SvNIOK(*MARK) || !i)
            a[i++] = SvIV(*MARK);
        else if (*MARK == &PL_sv_undef)
            a[i++] = 0;
        else
            a[i++] = (unsigned long)SvPV_force(*MARK, n_a);
        if (i > 15)
            break;
    }
    switch (items) {
    default:
        DIE(aTHX_ "Too many args to syscall");
    case 0:
        DIE(aTHX_ "Too few args to syscall");
    case 1:
        retval = syscall(a[0]);
        break;
    case 2:
        retval = syscall(a[0],a[1]);
        break;
    case 3:
        retval = syscall(a[0],a[1],a[2]);
        break;
    case 4:
        retval = syscall(a[0],a[1],a[2],a[3]);
        break;
    case 5:
        retval = syscall(a[0],a[1],a[2],a[3],a[4]);
        break;
    case 6:
        retval = syscall(a[0],a[1],a[2],a[3],a[4],a[5]);
        break;
    case 7:
        retval = syscall(a[0],a[1],a[2],a[3],a[4],a[5],a[6]);
        break;
    case 8:
        retval = syscall(a[0],a[1],a[2],a[3],a[4],a[5],a[6],a[7]);
        break;
#ifdef atarist
    case 9:
        retval = syscall(a[0],a[1],a[2],a[3],a[4],a[5],a[6],a[7],a[8]);
        break;
    case 10:
        retval = syscall(a[0],a[1],a[2],a[3],a[4],a[5],a[6],a[7],a[8],a[9]);
        break;
    case 11:
        retval = syscall(a[0],a[1],a[2],a[3],a[4],a[5],a[6],a[7],a[8],a[9],
          a[10]);
        break;
    case 12:
        retval = syscall(a[0],a[1],a[2],a[3],a[4],a[5],a[6],a[7],a[8],a[9],
          a[10],a[11]);
        break;
    case 13:
        retval = syscall(a[0],a[1],a[2],a[3],a[4],a[5],a[6],a[7],a[8],a[9],
          a[10],a[11],a[12]);
        break;
    case 14:
        retval = syscall(a[0],a[1],a[2],a[3],a[4],a[5],a[6],a[7],a[8],a[9],
          a[10],a[11],a[12],a[13]);
        break;
#endif /* atarist */
    }
    SP = ORIGMARK;
    PUSHi(retval);
    RETURN;
#else
    DIE(aTHX_ PL_no_func, "syscall");
#endif
}

#ifdef FCNTL_EMULATE_FLOCK

/*  XXX Emulate flock() with fcntl().
    What's really needed is a good file locking module.
*/

static int
fcntl_emulate_flock(int fd, int operation)
{
    struct flock flock;

    switch (operation & ~LOCK_NB) {
    case LOCK_SH:
        flock.l_type = F_RDLCK;
        break;
    case LOCK_EX:
        flock.l_type = F_WRLCK;
        break;
    case LOCK_UN:
        flock.l_type = F_UNLCK;
        break;
    default:
        errno = EINVAL;
        return -1;
    }
    flock.l_whence = SEEK_SET;
    flock.l_start = flock.l_len = (Off_t)0;

    return fcntl(fd, (operation & LOCK_NB) ? F_SETLK : F_SETLKW, &flock);
}

#endif /* FCNTL_EMULATE_FLOCK */

#ifdef LOCKF_EMULATE_FLOCK

/*  XXX Emulate flock() with lockf().  This is just to increase
    portability of scripts.  The calls are not completely
    interchangeable.  What's really needed is a good file
    locking module.
*/

/*  The lockf() constants might have been defined in <unistd.h>.
    Unfortunately, <unistd.h> causes troubles on some mixed
    (BSD/POSIX) systems, such as SunOS 4.1.3.

   Further, the lockf() constants aren't POSIX, so they might not be
   visible if we're compiling with _POSIX_SOURCE defined.  Thus, we'll
   just stick in the SVID values and be done with it.  Sigh.
*/

# ifndef F_ULOCK
#  define F_ULOCK       0       /* Unlock a previously locked region */
# endif
# ifndef F_LOCK
#  define F_LOCK        1       /* Lock a region for exclusive use */
# endif
# ifndef F_TLOCK
#  define F_TLOCK       2       /* Test and lock a region for exclusive use */
# endif
# ifndef F_TEST
#  define F_TEST        3       /* Test a region for other processes locks */
# endif

static int
lockf_emulate_flock(int fd, int operation)
{
    int i;
    int save_errno;
    Off_t pos;

    /* flock locks entire file so for lockf we need to do the same      */
    save_errno = errno;
    pos = PerlLIO_lseek(fd, (Off_t)0, SEEK_CUR);    /* get pos to restore later */
    if (pos > 0)        /* is seekable and needs to be repositioned     */
        if (PerlLIO_lseek(fd, (Off_t)0, SEEK_SET) < 0)
            pos = -1;   /* seek failed, so don't seek back afterwards   */
    errno = save_errno;

    switch (operation) {

        /* LOCK_SH - get a shared lock */
        case LOCK_SH:
        /* LOCK_EX - get an exclusive lock */
        case LOCK_EX:
            i = lockf (fd, F_LOCK, 0);
            break;

        /* LOCK_SH|LOCK_NB - get a non-blocking shared lock */
        case LOCK_SH|LOCK_NB:
        /* LOCK_EX|LOCK_NB - get a non-blocking exclusive lock */
        case LOCK_EX|LOCK_NB:
            i = lockf (fd, F_TLOCK, 0);
            if (i == -1)
                if ((errno == EAGAIN) || (errno == EACCES))
                    errno = EWOULDBLOCK;
            break;

        /* LOCK_UN - unlock (non-blocking is a no-op) */
        case LOCK_UN:
        case LOCK_UN|LOCK_NB:
            i = lockf (fd, F_ULOCK, 0);
            break;

        /* Default - can't decipher operation */
        default:
            i = -1;
            errno = EINVAL;
            break;
    }

    if (pos > 0)      /* need to restore position of the handle */
        PerlLIO_lseek(fd, pos, SEEK_SET);       /* ignore error here    */

    return (i);
}

#endif /* LOCKF_EMULATE_FLOCK */

/*
 * Local variables:
 * c-indentation-style: bsd
 * c-basic-offset: 4
 * indent-tabs-mode: t
 * End:
 *
 * vim: shiftwidth=4:
*/
Revision:	1.1
Committed:	Thu Jun 30 14:26:42 2005 UTC (21 years, 4 months ago) by root
Content type:	text/plain
Branch:	MAIN
CVS Tags:	PERL-5-8-7, HEAD
Branch point for:	PERL
Log Message:	* empty log message *