package File::Compare;
use warnings;
our($VERSION, @ISA, @EXPORT, @EXPORT_OK, $Too_Big);
require Exporter;
$VERSION = '1.1005';
@ISA = qw(Exporter);
@EXPORT = qw(compare);
@EXPORT_OK = qw(cmp compare_text);
$Too_Big = 1024 * 1024 * 2;
sub compare {
die("Usage: compare( file1, file2 [, buffersize]) ")
unless((nelems @_) == 2 || (nelems @_) == 3);
my @($from,$to,?$size) = @_;
my $text_mode = defined($size) && (ref($size) eq 'CODE' || $size +< 0);
my ($fromsize,$closefrom,$closeto);
my $from_fh;
my $to_fh;
my $fail_open1 = sub { return -1; };
my $fail_open2 =
sub {
if ($closefrom) {
my $status = $^OS_ERROR;
$^OS_ERROR = 0;
close $from_fh;
$^OS_ERROR = $status unless $^OS_ERROR;
}
return $fail_open1->();
};
# All of these contortions try to preserve error messages...
my $fail_inner =
sub {
close($to_fh) || return $fail_open2->() if $closeto;
close($from_fh) || return $fail_open1->() if $closefrom;
return 1;
};
die("from undefined") unless (defined $from);
die("to undefined") unless (defined $to);
if (ref($from) &&
(UNIVERSAL::isa($from,'GLOB') || UNIVERSAL::isa($from,'IO::Handle'))) {
$from_fh = $from;
} elsif (ref(\$from) eq 'GLOB') {
$from_fh = \$from;
} else {
open($from_fh,"<",$from) or return $fail_open1->();
unless ($text_mode) {
binmode $from_fh;
$fromsize = -s $from_fh;
}
$closefrom = 1;
}
if (ref($to) &&
(UNIVERSAL::isa($to,'GLOB') || UNIVERSAL::isa($to,'IO::Handle'))) {
$to_fh = $to;
} elsif (ref(\$to) eq 'GLOB') {
$to_fh = \$to;
} else {
open($to_fh,"<",$to) or return $fail_open2->();
binmode $to_fh unless $text_mode;
$closeto = 1;
}
if (!$text_mode && $closefrom && $closeto) {
# If both are opened files we know they differ if their size differ
return $fail_inner->() if $fromsize != -s $to_fh;
}
if ($text_mode) {
local $^INPUT_RECORD_SEPARATOR = "\n";
my ($fline,$tline);
while (defined($fline = ~< $from_fh)) {
return $fail_inner->() unless defined($tline = ~< $to_fh);
if (ref $size) {
# $size contains ref to comparison function
return $fail_inner->() if &$size($fline, $tline);
} else {
return $fail_inner->() if $fline ne $tline;
}
}
return $fail_inner->() if defined($tline = ~< $to_fh);
}
else {
unless (defined($size) && $size +> 0) {
$size = $fromsize || -s $to_fh || 0;
$size = 1024 if $size +< 512;
$size = $Too_Big if $size +> $Too_Big;
}
my ($fr,$tr,$fbuf,$tbuf);
$fbuf = $tbuf = '';
while(defined($fr = read($from_fh,$fbuf,$size)) && $fr +> 0) {
unless (defined($tr = read($to_fh,$tbuf,$fr)) && $tbuf eq $fbuf) {
return $fail_inner->();
}
}
return $fail_inner->() if defined($tr = read($to_fh,$tbuf,$size)) && $tr +> 0;
}
close($to_fh) || return $fail_open2->() if $closeto;
close($from_fh) || return $fail_open1->() if $closefrom;
return 0;
}
*cmp = \&compare;
sub compare_text {
my @($from,$to,?$cmp) = @_;
die("Usage: compare_text( file1, file2 [, cmp-function])")
unless (nelems @_) == 2 || (nelems @_) == 3;
die("Third arg to compare_text() function must be a code reference")
if (nelems @_) == 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