freebsd-dev/contrib/perl5/lib/File/Compare.pm

144 lines
3.0 KiB
Perl

package File::Compare;
use strict;
use vars qw($VERSION @ISA @EXPORT @EXPORT_OK $Too_Big *FROM *TO);
require Exporter;
use Carp;
$VERSION = '1.1001';
@ISA = qw(Exporter);
@EXPORT = qw(compare);
@EXPORT_OK = qw(cmp);
$Too_Big = 1024 * 1024 * 2;
sub VERSION {
# Version of File::Compare
return $File::Compare::VERSION;
}
sub compare {
croak("Usage: compare( file1, file2 [, buffersize]) ")
unless(@_ == 2 || @_ == 3);
my $from = shift;
my $to = shift;
my $closefrom=0;
my $closeto=0;
my ($size, $fromsize, $status, $fr, $tr, $fbuf, $tbuf);
local(*FROM, *TO);
local($\) = '';
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;
binmode FROM;
$closefrom = 1;
$fromsize = -s FROM;
}
if (ref($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;
$closeto = 1;
}
if ($closefrom && $closeto) {
# If both are opened files we know they differ if their size differ
goto fail_inner if $fromsize != -s TO;
}
if (@_) {
$size = shift(@_) + 0;
croak("Bad buffer size for compare: $size\n") unless ($size > 0);
} else {
$size = $fromsize;
$size = 1024 if ($size < 512);
$size = $Too_Big if ($size > $Too_Big);
}
$fbuf = '';
$tbuf = '';
while(defined($fr = read(FROM,$fbuf,$size)) && $fr > 0) {
unless (defined($tr = read(TO,$tbuf,$fr)) and $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) {
$status = $!;
$! = 0;
close FROM;
$! = $status unless $!;
}
fail_open1:
return -1;
}
*cmp = \&compare;
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.
=head1 RETURN
File::Compare::compare 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