lib/File/Compare.pm

package File::Compare;

use 5.006;
use strict;
use warnings;
our($VERSION, @ISA, @EXPORT, @EXPORT_OK, $Too_Big);

require Exporter;
use Carp;

$VERSION = '1.1003';
@ISA = qw(Exporter);
@EXPORT = qw(compare);
@EXPORT_OK = qw(cmp compare_text);

$Too_Big = 1024 * 1024 * 2;

sub compare {
    croak("Usage: compare( file1, file2 [, buffersize]) ")
      unless(@_ == 2 || @_ == 3);

    my ($from,$to,$size) = @_;
    my $text_mode = defined($size) && (ref($size) eq 'CODE' || $size < 0);

    my ($fromsize,$closefrom,$closeto);
    local (*FROM, *TO);

    croak("from undefined") unless (defined $from);
    croak("to undefined") unless (defined $to);

    if (ref($from) && 
        (UNIVERSAL::isa($from,'GLOB') || UNIVERSAL::isa($from,'IO::Handle'))) {
        *FROM = *$from;
    } elsif (ref(\$from) eq 'GLOB') {
        *FROM = $from;
    } else {
        open(FROM,"<$from") or goto fail_open1;
        unless ($text_mode) {
            binmode FROM;
            $fromsize = -s FROM;
        }
        $closefrom = 1;
    }

    if (ref($to) &&
        (UNIVERSAL::isa($to,'GLOB') || UNIVERSAL::isa($to,'IO::Handle'))) {
        *TO = *$to;
    } elsif (ref(\$to) eq 'GLOB') {
        *TO = $to;
    } else {
        open(TO,"<$to") or goto fail_open2;
        binmode TO unless $text_mode;
        $closeto = 1;
    }

    if (!$text_mode && $closefrom && $closeto) {
        # If both are opened files we know they differ if their size differ
        goto fail_inner if $fromsize != -s TO;
    }

    if ($text_mode) {
        local $/ = "\n";
        my ($fline,$tline);
        while (defined($fline = <FROM>)) {
            goto fail_inner unless defined($tline = <TO>);
            if (ref $size) {
                # $size contains ref to comparison function
                goto fail_inner if &$size($fline, $tline);
            } else {
                goto fail_inner if $fline ne $tline;
            }
        }
        goto fail_inner if defined($tline = <TO>);
    }
    else {
        unless (defined($size) && $size > 0) {
            $size = $fromsize || -s TO || 0;
            $size = 1024 if $size < 512;
            $size = $Too_Big if $size > $Too_Big;
        }

        my ($fr,$tr,$fbuf,$tbuf);
        $fbuf = $tbuf = '';
        while(defined($fr = read(FROM,$fbuf,$size)) && $fr > 0) {
            unless (defined($tr = read(TO,$tbuf,$fr)) && $tbuf eq $fbuf) {
                goto fail_inner;
            }
        }
        goto fail_inner if defined($tr = read(TO,$tbuf,$size)) && $tr > 0;
    }

    close(TO) || goto fail_open2 if $closeto;
    close(FROM) || goto fail_open1 if $closefrom;

    return 0;
    
  # All of these contortions try to preserve error messages...
  fail_inner:
    close(TO) || goto fail_open2 if $closeto;
    close(FROM) || goto fail_open1 if $closefrom;

    return 1;

  fail_open2:
    if ($closefrom) {
        my $status = $!;
        $! = 0;
        close FROM;
        $! = $status unless $!;
    }
  fail_open1:
    return -1;
}

sub cmp;
*cmp = \&compare;

sub compare_text {
    my ($from,$to,$cmp) = @_;
    croak("Usage: compare_text( file1, file2 [, cmp-function])")
        unless @_ == 2 || @_ == 3;
    croak("Third arg to compare_text() function must be a code reference")
        if @_ == 3 && ref($cmp) ne 'CODE';

    # Using a negative buffer size puts compare into text_mode too
    $cmp = -1 unless defined $cmp;
    compare($from, $to, $cmp);
}

1;

__END__

=head1 NAME

File::Compare - Compare files or filehandles

=head1 SYNOPSIS

        use File::Compare;

        if (compare("file1","file2") == 0) {
            print "They're equal\n";
        }

=head1 DESCRIPTION

The File::Compare::compare function compares the contents of two
sources, each of which can be a file or a file handle.  It is exported
from File::Compare by default.

File::Compare::cmp is a synonym for File::Compare::compare.  It is
exported from File::Compare only by request.

File::Compare::compare_text does a line by line comparison of the two
files. It stops as soon as a difference is detected. compare_text()
accepts an optional third argument: This must be a CODE reference to
a line comparison function, which returns 0 when both lines are considered
equal. For example:

    compare_text($file1, $file2)

is basically equivalent to

    compare_text($file1, $file2, sub {$_[0] ne $_[1]} )

=head1 RETURN

File::Compare::compare and its sibling functions return 0 if the files
are equal, 1 if the files are unequal, or -1 if an error was encountered.

=head1 AUTHOR

File::Compare was written by Nick Ing-Simmons.
Its original documentation was written by Chip Salzenberg.

=cut

Revision:	1.1
Committed:	Thu Jun 30 14:27:11 2005 UTC (21 years, 4 months ago) by root
Branch:	MAIN
CVS Tags:	PERL-5-8-7, HEAD
Branch point for:	PERL
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	package File::Compare;
2
3			use 5.006;
4			use strict;
5			use warnings;
6			our($VERSION, @ISA, @EXPORT, @EXPORT_OK, $Too_Big);
7
8			require Exporter;
9			use Carp;
10
11			$VERSION = '1.1003';
12			@ISA = qw(Exporter);
13			@EXPORT = qw(compare);
14			@EXPORT_OK = qw(cmp compare_text);
15
16			$Too_Big = 1024 * 1024 * 2;
17
18			sub compare {
19			croak("Usage: compare( file1, file2 [, buffersize]) ")
20			unless(@_ == 2 \|\| @_ == 3);
21
22			my ($from,$to,$size) = @_;
23			my $text_mode = defined($size) && (ref($size) eq 'CODE' \|\| $size < 0);
24
25			my ($fromsize,$closefrom,$closeto);
26			local (FROM, TO);
27
28			croak("from undefined") unless (defined $from);
29			croak("to undefined") unless (defined $to);
30
31			if (ref($from) &&
32			(UNIVERSAL::isa($from,'GLOB') \|\| UNIVERSAL::isa($from,'IO::Handle'))) {
33			FROM = $from;
34			} elsif (ref(\$from) eq 'GLOB') {
35			*FROM = $from;
36			} else {
37			open(FROM,"<$from") or goto fail_open1;
38			unless ($text_mode) {
39			binmode FROM;
40			$fromsize = -s FROM;
41			}
42			$closefrom = 1;
43			}
44
45			if (ref($to) &&
46			(UNIVERSAL::isa($to,'GLOB') \|\| UNIVERSAL::isa($to,'IO::Handle'))) {
47			TO = $to;
48			} elsif (ref(\$to) eq 'GLOB') {
49			*TO = $to;
50			} else {
51			open(TO,"<$to") or goto fail_open2;
52			binmode TO unless $text_mode;
53			$closeto = 1;
54			}
55
56			if (!$text_mode && $closefrom && $closeto) {
57			# If both are opened files we know they differ if their size differ
58			goto fail_inner if $fromsize != -s TO;
59			}
60
61			if ($text_mode) {
62			local $/ = "\n";
63			my ($fline,$tline);
64			while (defined($fline = <FROM>)) {
65			goto fail_inner unless defined($tline = <TO>);
66			if (ref $size) {
67			# $size contains ref to comparison function
68			goto fail_inner if &$size($fline, $tline);
69			} else {
70			goto fail_inner if $fline ne $tline;
71			}
72			}
73			goto fail_inner if defined($tline = <TO>);
74			}
75			else {
76			unless (defined($size) && $size > 0) {
77			$size = $fromsize \|\| -s TO \|\| 0;
78			$size = 1024 if $size < 512;
79			$size = $Too_Big if $size > $Too_Big;
80			}
81
82			my ($fr,$tr,$fbuf,$tbuf);
83			$fbuf = $tbuf = '';
84			while(defined($fr = read(FROM,$fbuf,$size)) && $fr > 0) {
85			unless (defined($tr = read(TO,$tbuf,$fr)) && $tbuf eq $fbuf) {
86			goto fail_inner;
87			}
88			}
89			goto fail_inner if defined($tr = read(TO,$tbuf,$size)) && $tr > 0;
90			}
91
92			close(TO) \|\| goto fail_open2 if $closeto;
93			close(FROM) \|\| goto fail_open1 if $closefrom;
94
95			return 0;
96
97			# All of these contortions try to preserve error messages...
98			fail_inner:
99			close(TO) \|\| goto fail_open2 if $closeto;
100			close(FROM) \|\| goto fail_open1 if $closefrom;
101
102			return 1;
103
104			fail_open2:
105			if ($closefrom) {
106			my $status = $!;
107			$! = 0;
108			close FROM;
109			$! = $status unless $!;
110			}
111			fail_open1:
112			return -1;
113			}
114
115			sub cmp;
116			*cmp = \&compare;
117
118			sub compare_text {
119			my ($from,$to,$cmp) = @_;
120			croak("Usage: compare_text( file1, file2 [, cmp-function])")
121			unless @_ == 2 \|\| @_ == 3;
122			croak("Third arg to compare_text() function must be a code reference")
123			if @_ == 3 && ref($cmp) ne 'CODE';
124
125			# Using a negative buffer size puts compare into text_mode too
126			$cmp = -1 unless defined $cmp;
127			compare($from, $to, $cmp);
128			}
129
130			1;
131
132			__END__
133
134			=head1 NAME
135
136			File::Compare - Compare files or filehandles
137
138			=head1 SYNOPSIS
139
140			use File::Compare;
141
142			if (compare("file1","file2") == 0) {
143			print "They're equal\n";
144			}
145
146			=head1 DESCRIPTION
147
148			The File::Compare::compare function compares the contents of two
149			sources, each of which can be a file or a file handle. It is exported
150			from File::Compare by default.
151
152			File::Compare::cmp is a synonym for File::Compare::compare. It is
153			exported from File::Compare only by request.
154
155			File::Compare::compare_text does a line by line comparison of the two
156			files. It stops as soon as a difference is detected. compare_text()
157			accepts an optional third argument: This must be a CODE reference to
158			a line comparison function, which returns 0 when both lines are considered
159			equal. For example:
160
161			compare_text($file1, $file2)
162
163			is basically equivalent to
164
165			compare_text($file1, $file2, sub {$_[0] ne $_[1]} )
166
167			=head1 RETURN
168
169			File::Compare::compare and its sibling functions return 0 if the files
170			are equal, 1 if the files are unequal, or -1 if an error was encountered.
171
172			=head1 AUTHOR
173
174			File::Compare was written by Nick Ing-Simmons.
175			Its original documentation was written by Chip Salzenberg.
176
177			=cut
178