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- package File::Compare;
- use 5.006;
- use strict;
- use warnings;
- our($VERSION, @ISA, @EXPORT, @EXPORT_OK, $Too_Big);
- require Exporter;
- $VERSION = '1.1006';
- @ISA = qw(Exporter);
- @EXPORT = qw(compare);
- @EXPORT_OK = qw(cmp compare_text);
- $Too_Big = 1024 * 1024 * 2;
- sub croak {
- require Carp;
- goto &Carp::croak;
- }
- sub compare {
- croak("Usage: compare( file1, file2 [, buffersize]) ")
- unless(@_ == 2 || @_ == 3);
- my ($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
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