| 1 |
=head1 NAME |
| 2 |
|
| 3 |
Term::ReadLine - Perl interface to various C<readline> packages. |
| 4 |
If no real package is found, substitutes stubs instead of basic functions. |
| 5 |
|
| 6 |
=head1 SYNOPSIS |
| 7 |
|
| 8 |
use Term::ReadLine; |
| 9 |
my $term = new Term::ReadLine 'Simple Perl calc'; |
| 10 |
my $prompt = "Enter your arithmetic expression: "; |
| 11 |
my $OUT = $term->OUT || \*STDOUT; |
| 12 |
while ( defined ($_ = $term->readline($prompt)) ) { |
| 13 |
my $res = eval($_); |
| 14 |
warn $@ if $@; |
| 15 |
print $OUT $res, "\n" unless $@; |
| 16 |
$term->addhistory($_) if /\S/; |
| 17 |
} |
| 18 |
|
| 19 |
=head1 DESCRIPTION |
| 20 |
|
| 21 |
This package is just a front end to some other packages. At the moment |
| 22 |
this description is written, the only such package is Term-ReadLine, |
| 23 |
available on CPAN near you. The real target of this stub package is to |
| 24 |
set up a common interface to whatever Readline emerges with time. |
| 25 |
|
| 26 |
=head1 Minimal set of supported functions |
| 27 |
|
| 28 |
All the supported functions should be called as methods, i.e., either as |
| 29 |
|
| 30 |
$term = new Term::ReadLine 'name'; |
| 31 |
|
| 32 |
or as |
| 33 |
|
| 34 |
$term->addhistory('row'); |
| 35 |
|
| 36 |
where $term is a return value of Term::ReadLine-E<gt>new(). |
| 37 |
|
| 38 |
=over 12 |
| 39 |
|
| 40 |
=item C<ReadLine> |
| 41 |
|
| 42 |
returns the actual package that executes the commands. Among possible |
| 43 |
values are C<Term::ReadLine::Gnu>, C<Term::ReadLine::Perl>, |
| 44 |
C<Term::ReadLine::Stub>. |
| 45 |
|
| 46 |
=item C<new> |
| 47 |
|
| 48 |
returns the handle for subsequent calls to following |
| 49 |
functions. Argument is the name of the application. Optionally can be |
| 50 |
followed by two arguments for C<IN> and C<OUT> filehandles. These |
| 51 |
arguments should be globs. |
| 52 |
|
| 53 |
=item C<readline> |
| 54 |
|
| 55 |
gets an input line, I<possibly> with actual C<readline> |
| 56 |
support. Trailing newline is removed. Returns C<undef> on C<EOF>. |
| 57 |
|
| 58 |
=item C<addhistory> |
| 59 |
|
| 60 |
adds the line to the history of input, from where it can be used if |
| 61 |
the actual C<readline> is present. |
| 62 |
|
| 63 |
=item C<IN>, C<OUT> |
| 64 |
|
| 65 |
return the filehandles for input and output or C<undef> if C<readline> |
| 66 |
input and output cannot be used for Perl. |
| 67 |
|
| 68 |
=item C<MinLine> |
| 69 |
|
| 70 |
If argument is specified, it is an advice on minimal size of line to |
| 71 |
be included into history. C<undef> means do not include anything into |
| 72 |
history. Returns the old value. |
| 73 |
|
| 74 |
=item C<findConsole> |
| 75 |
|
| 76 |
returns an array with two strings that give most appropriate names for |
| 77 |
files for input and output using conventions C<"E<lt>$in">, C<"E<gt>out">. |
| 78 |
|
| 79 |
=item Attribs |
| 80 |
|
| 81 |
returns a reference to a hash which describes internal configuration |
| 82 |
of the package. Names of keys in this hash conform to standard |
| 83 |
conventions with the leading C<rl_> stripped. |
| 84 |
|
| 85 |
=item C<Features> |
| 86 |
|
| 87 |
Returns a reference to a hash with keys being features present in |
| 88 |
current implementation. Several optional features are used in the |
| 89 |
minimal interface: C<appname> should be present if the first argument |
| 90 |
to C<new> is recognized, and C<minline> should be present if |
| 91 |
C<MinLine> method is not dummy. C<autohistory> should be present if |
| 92 |
lines are put into history automatically (maybe subject to |
| 93 |
C<MinLine>), and C<addhistory> if C<addhistory> method is not dummy. |
| 94 |
|
| 95 |
If C<Features> method reports a feature C<attribs> as present, the |
| 96 |
method C<Attribs> is not dummy. |
| 97 |
|
| 98 |
=back |
| 99 |
|
| 100 |
=head1 Additional supported functions |
| 101 |
|
| 102 |
Actually C<Term::ReadLine> can use some other package, that will |
| 103 |
support reacher set of commands. |
| 104 |
|
| 105 |
All these commands are callable via method interface and have names |
| 106 |
which conform to standard conventions with the leading C<rl_> stripped. |
| 107 |
|
| 108 |
The stub package included with the perl distribution allows some |
| 109 |
additional methods: |
| 110 |
|
| 111 |
=over 12 |
| 112 |
|
| 113 |
=item C<tkRunning> |
| 114 |
|
| 115 |
makes Tk event loop run when waiting for user input (i.e., during |
| 116 |
C<readline> method). |
| 117 |
|
| 118 |
=item C<ornaments> |
| 119 |
|
| 120 |
makes the command line stand out by using termcap data. The argument |
| 121 |
to C<ornaments> should be 0, 1, or a string of a form |
| 122 |
C<"aa,bb,cc,dd">. Four components of this string should be names of |
| 123 |
I<terminal capacities>, first two will be issued to make the prompt |
| 124 |
standout, last two to make the input line standout. |
| 125 |
|
| 126 |
=item C<newTTY> |
| 127 |
|
| 128 |
takes two arguments which are input filehandle and output filehandle. |
| 129 |
Switches to use these filehandles. |
| 130 |
|
| 131 |
=back |
| 132 |
|
| 133 |
One can check whether the currently loaded ReadLine package supports |
| 134 |
these methods by checking for corresponding C<Features>. |
| 135 |
|
| 136 |
=head1 EXPORTS |
| 137 |
|
| 138 |
None |
| 139 |
|
| 140 |
=head1 ENVIRONMENT |
| 141 |
|
| 142 |
The environment variable C<PERL_RL> governs which ReadLine clone is |
| 143 |
loaded. If the value is false, a dummy interface is used. If the value |
| 144 |
is true, it should be tail of the name of the package to use, such as |
| 145 |
C<Perl> or C<Gnu>. |
| 146 |
|
| 147 |
As a special case, if the value of this variable is space-separated, |
| 148 |
the tail might be used to disable the ornaments by setting the tail to |
| 149 |
be C<o=0> or C<ornaments=0>. The head should be as described above, say |
| 150 |
|
| 151 |
If the variable is not set, or if the head of space-separated list is |
| 152 |
empty, the best available package is loaded. |
| 153 |
|
| 154 |
export "PERL_RL=Perl o=0" # Use Perl ReadLine without ornaments |
| 155 |
export "PERL_RL= o=0" # Use best available ReadLine without ornaments |
| 156 |
|
| 157 |
(Note that processing of C<PERL_RL> for ornaments is in the discretion of the |
| 158 |
particular used C<Term::ReadLine::*> package). |
| 159 |
|
| 160 |
=head1 CAVEATS |
| 161 |
|
| 162 |
It seems that using Term::ReadLine from Emacs minibuffer doesn't work |
| 163 |
quite right and one will get an error message like |
| 164 |
|
| 165 |
Cannot open /dev/tty for read at ... |
| 166 |
|
| 167 |
One possible workaround for this is to explicitly open /dev/tty like this |
| 168 |
|
| 169 |
open (FH, "/dev/tty" ) |
| 170 |
or eval 'sub Term::ReadLine::findConsole { ("&STDIN", "&STDERR") }'; |
| 171 |
die $@ if $@; |
| 172 |
close (FH); |
| 173 |
|
| 174 |
or you can try using the 4-argument form of Term::ReadLine->new(). |
| 175 |
|
| 176 |
=cut |
| 177 |
|
| 178 |
use strict; |
| 179 |
|
| 180 |
package Term::ReadLine::Stub; |
| 181 |
our @ISA = qw'Term::ReadLine::Tk Term::ReadLine::TermCap'; |
| 182 |
|
| 183 |
$DB::emacs = $DB::emacs; # To peacify -w |
| 184 |
our @rl_term_set; |
| 185 |
*rl_term_set = \@Term::ReadLine::TermCap::rl_term_set; |
| 186 |
|
| 187 |
sub PERL_UNICODE_STDIN () { 0x0001 } |
| 188 |
|
| 189 |
sub ReadLine {'Term::ReadLine::Stub'} |
| 190 |
sub readline { |
| 191 |
my $self = shift; |
| 192 |
my ($in,$out,$str) = @$self; |
| 193 |
my $prompt = shift; |
| 194 |
print $out $rl_term_set[0], $prompt, $rl_term_set[1], $rl_term_set[2]; |
| 195 |
$self->register_Tk |
| 196 |
if not $Term::ReadLine::registered and $Term::ReadLine::toloop |
| 197 |
and defined &Tk::DoOneEvent; |
| 198 |
#$str = scalar <$in>; |
| 199 |
$str = $self->get_line; |
| 200 |
$str =~ s/^\s*\Q$prompt\E// if ($^O eq 'MacOS'); |
| 201 |
utf8::upgrade($str) |
| 202 |
if (${^UNICODE} & PERL_UNICODE_STDIN || defined ${^ENCODING}) && |
| 203 |
utf8::valid($str); |
| 204 |
print $out $rl_term_set[3]; |
| 205 |
# bug in 5.000: chomping empty string creats length -1: |
| 206 |
chomp $str if defined $str; |
| 207 |
$str; |
| 208 |
} |
| 209 |
sub addhistory {} |
| 210 |
|
| 211 |
sub findConsole { |
| 212 |
my $console; |
| 213 |
|
| 214 |
if ($^O eq 'MacOS') { |
| 215 |
$console = "Dev:Console"; |
| 216 |
} elsif (-e "/dev/tty") { |
| 217 |
$console = "/dev/tty"; |
| 218 |
} elsif (-e "con" or $^O eq 'MSWin32') { |
| 219 |
$console = "con"; |
| 220 |
} else { |
| 221 |
$console = "sys\$command"; |
| 222 |
} |
| 223 |
|
| 224 |
if (($^O eq 'amigaos') || ($^O eq 'beos') || ($^O eq 'epoc')) { |
| 225 |
$console = undef; |
| 226 |
} |
| 227 |
elsif ($^O eq 'os2') { |
| 228 |
if ($DB::emacs) { |
| 229 |
$console = undef; |
| 230 |
} else { |
| 231 |
$console = "/dev/con"; |
| 232 |
} |
| 233 |
} |
| 234 |
|
| 235 |
my $consoleOUT = $console; |
| 236 |
$console = "&STDIN" unless defined $console; |
| 237 |
if (!defined $consoleOUT) { |
| 238 |
$consoleOUT = defined fileno(STDERR) ? "&STDERR" : "&STDOUT"; |
| 239 |
} |
| 240 |
($console,$consoleOUT); |
| 241 |
} |
| 242 |
|
| 243 |
sub new { |
| 244 |
die "method new called with wrong number of arguments" |
| 245 |
unless @_==2 or @_==4; |
| 246 |
#local (*FIN, *FOUT); |
| 247 |
my ($FIN, $FOUT, $ret); |
| 248 |
if (@_==2) { |
| 249 |
my($console, $consoleOUT) = $_[0]->findConsole; |
| 250 |
|
| 251 |
open(FIN, "<$console"); |
| 252 |
open(FOUT,">$consoleOUT"); |
| 253 |
#OUT->autoflush(1); # Conflicts with debugger? |
| 254 |
my $sel = select(FOUT); |
| 255 |
$| = 1; # for DB::OUT |
| 256 |
select($sel); |
| 257 |
$ret = bless [\*FIN, \*FOUT]; |
| 258 |
} else { # Filehandles supplied |
| 259 |
$FIN = $_[2]; $FOUT = $_[3]; |
| 260 |
#OUT->autoflush(1); # Conflicts with debugger? |
| 261 |
my $sel = select($FOUT); |
| 262 |
$| = 1; # for DB::OUT |
| 263 |
select($sel); |
| 264 |
$ret = bless [$FIN, $FOUT]; |
| 265 |
} |
| 266 |
if ($ret->Features->{ornaments} |
| 267 |
and not ($ENV{PERL_RL} and $ENV{PERL_RL} =~ /\bo\w*=0/)) { |
| 268 |
local $Term::ReadLine::termcap_nowarn = 1; |
| 269 |
$ret->ornaments(1); |
| 270 |
} |
| 271 |
return $ret; |
| 272 |
} |
| 273 |
|
| 274 |
sub newTTY { |
| 275 |
my ($self, $in, $out) = @_; |
| 276 |
$self->[0] = $in; |
| 277 |
$self->[1] = $out; |
| 278 |
my $sel = select($out); |
| 279 |
$| = 1; # for DB::OUT |
| 280 |
select($sel); |
| 281 |
} |
| 282 |
|
| 283 |
sub IN { shift->[0] } |
| 284 |
sub OUT { shift->[1] } |
| 285 |
sub MinLine { undef } |
| 286 |
sub Attribs { {} } |
| 287 |
|
| 288 |
my %features = (tkRunning => 1, ornaments => 1, 'newTTY' => 1); |
| 289 |
sub Features { \%features } |
| 290 |
|
| 291 |
package Term::ReadLine; # So late to allow the above code be defined? |
| 292 |
|
| 293 |
our $VERSION = '1.01'; |
| 294 |
|
| 295 |
my ($which) = exists $ENV{PERL_RL} ? split /\s+/, $ENV{PERL_RL} : undef; |
| 296 |
if ($which) { |
| 297 |
if ($which =~ /\bgnu\b/i){ |
| 298 |
eval "use Term::ReadLine::Gnu;"; |
| 299 |
} elsif ($which =~ /\bperl\b/i) { |
| 300 |
eval "use Term::ReadLine::Perl;"; |
| 301 |
} else { |
| 302 |
eval "use Term::ReadLine::$which;"; |
| 303 |
} |
| 304 |
} elsif (defined $which and $which ne '') { # Defined but false |
| 305 |
# Do nothing fancy |
| 306 |
} else { |
| 307 |
eval "use Term::ReadLine::Gnu; 1" or eval "use Term::ReadLine::Perl; 1"; |
| 308 |
} |
| 309 |
|
| 310 |
#require FileHandle; |
| 311 |
|
| 312 |
# To make possible switch off RL in debugger: (Not needed, work done |
| 313 |
# in debugger). |
| 314 |
our @ISA; |
| 315 |
if (defined &Term::ReadLine::Gnu::readline) { |
| 316 |
@ISA = qw(Term::ReadLine::Gnu Term::ReadLine::Stub); |
| 317 |
} elsif (defined &Term::ReadLine::Perl::readline) { |
| 318 |
@ISA = qw(Term::ReadLine::Perl Term::ReadLine::Stub); |
| 319 |
} elsif (defined $which && defined &{"Term::ReadLine::$which\::readline"}) { |
| 320 |
@ISA = "Term::ReadLine::$which"; |
| 321 |
} else { |
| 322 |
@ISA = qw(Term::ReadLine::Stub); |
| 323 |
} |
| 324 |
|
| 325 |
package Term::ReadLine::TermCap; |
| 326 |
|
| 327 |
# Prompt-start, prompt-end, command-line-start, command-line-end |
| 328 |
# -- zero-width beautifies to emit around prompt and the command line. |
| 329 |
our @rl_term_set = ("","","",""); |
| 330 |
# string encoded: |
| 331 |
our $rl_term_set = ',,,'; |
| 332 |
|
| 333 |
our $terminal; |
| 334 |
sub LoadTermCap { |
| 335 |
return if defined $terminal; |
| 336 |
|
| 337 |
require Term::Cap; |
| 338 |
$terminal = Tgetent Term::Cap ({OSPEED => 9600}); # Avoid warning. |
| 339 |
} |
| 340 |
|
| 341 |
sub ornaments { |
| 342 |
shift; |
| 343 |
return $rl_term_set unless @_; |
| 344 |
$rl_term_set = shift; |
| 345 |
$rl_term_set ||= ',,,'; |
| 346 |
$rl_term_set = 'us,ue,md,me' if $rl_term_set eq '1'; |
| 347 |
my @ts = split /,/, $rl_term_set, 4; |
| 348 |
eval { LoadTermCap }; |
| 349 |
unless (defined $terminal) { |
| 350 |
warn("Cannot find termcap: $@\n") unless $Term::ReadLine::termcap_nowarn; |
| 351 |
$rl_term_set = ',,,'; |
| 352 |
return; |
| 353 |
} |
| 354 |
@rl_term_set = map {$_ ? $terminal->Tputs($_,1) || '' : ''} @ts; |
| 355 |
return $rl_term_set; |
| 356 |
} |
| 357 |
|
| 358 |
|
| 359 |
package Term::ReadLine::Tk; |
| 360 |
|
| 361 |
our($count_handle, $count_DoOne, $count_loop); |
| 362 |
$count_handle = $count_DoOne = $count_loop = 0; |
| 363 |
|
| 364 |
our($giveup); |
| 365 |
sub handle {$giveup = 1; $count_handle++} |
| 366 |
|
| 367 |
sub Tk_loop { |
| 368 |
# Tk->tkwait('variable',\$giveup); # needs Widget |
| 369 |
$count_DoOne++, Tk::DoOneEvent(0) until $giveup; |
| 370 |
$count_loop++; |
| 371 |
$giveup = 0; |
| 372 |
} |
| 373 |
|
| 374 |
sub register_Tk { |
| 375 |
my $self = shift; |
| 376 |
$Term::ReadLine::registered++ |
| 377 |
or Tk->fileevent($self->IN,'readable',\&handle); |
| 378 |
} |
| 379 |
|
| 380 |
sub tkRunning { |
| 381 |
$Term::ReadLine::toloop = $_[1] if @_ > 1; |
| 382 |
$Term::ReadLine::toloop; |
| 383 |
} |
| 384 |
|
| 385 |
sub get_c { |
| 386 |
my $self = shift; |
| 387 |
$self->Tk_loop if $Term::ReadLine::toloop && defined &Tk::DoOneEvent; |
| 388 |
return getc $self->IN; |
| 389 |
} |
| 390 |
|
| 391 |
sub get_line { |
| 392 |
my $self = shift; |
| 393 |
$self->Tk_loop if $Term::ReadLine::toloop && defined &Tk::DoOneEvent; |
| 394 |
my $in = $self->IN; |
| 395 |
local ($/) = "\n"; |
| 396 |
return scalar <$in>; |
| 397 |
} |
| 398 |
|
| 399 |
1; |
| 400 |
|
