lib/perl5/5.6.1/File/Compare.pm

   1 package File::Compare;
   2
   3 use 5.005_64;
   4 use strict;
   5 our($VERSION, @ISA, @EXPORT, @EXPORT_OK, $Too_Big);
   6
   7 require Exporter;
   8 use Carp;
   9
  10 $VERSION = '1.1002';
  11 @ISA = qw(Exporter);
  12 @EXPORT = qw(compare);
  13 @EXPORT_OK = qw(cmp compare_text);
  14
  15 $Too_Big = 1024 * 1024 * 2;
  16
  17 sub VERSION {
  18     # Version of File::Compare
  19     return $File::Compare::VERSION;
  20 }
  21
  22 sub compare {
  23     croak("Usage: compare( file1, file2 [, buffersize]) ")
  24       unless(@_ == 2 || @_ == 3);
  25
  26     my ($from,$to,$size) = @_;
  27     my $text_mode = defined($size) && (ref($size) eq 'CODE' || $size < 0);
  28
  29     my ($fromsize,$closefrom,$closeto);
  30     local (*FROM, *TO);
  31
  32     croak("from undefined") unless (defined $from);
  33     croak("to undefined") unless (defined $to);
  34
  35     if (ref($from) &&
  36         (UNIVERSAL::isa($from,'GLOB') || UNIVERSAL::isa($from,'IO::Handle'))) {
  37         *FROM = *$from;
  38     } elsif (ref(\$from) eq 'GLOB') {
  39         *FROM = $from;
  40     } else {
  41         open(FROM,"<$from") or goto fail_open1;
  42         unless ($text_mode) {
  43             binmode FROM;
  44             $fromsize = -s FROM;
  45         }
  46         $closefrom = 1;
  47     }
  48
  49     if (ref($to) &&
  50         (UNIVERSAL::isa($to,'GLOB') || UNIVERSAL::isa($to,'IO::Handle'))) {
  51         *TO = *$to;
  52     } elsif (ref(\$to) eq 'GLOB') {
  53         *TO = $to;
  54     } else {
  55         open(TO,"<$to") or goto fail_open2;
  56         binmode TO unless $text_mode;
  57         $closeto = 1;
  58     }
  59
  60     if (!$text_mode && $closefrom && $closeto) {
  61         # If both are opened files we know they differ if their size differ
  62         goto fail_inner if $fromsize != -s TO;
  63     }
  64
  65     if ($text_mode) {
  66         local $/ = "\n";
  67         my ($fline,$tline);
  68         while (defined($fline = <FROM>)) {
  69             goto fail_inner unless defined($tline = <TO>);
  70             if (ref $size) {
  71                 # $size contains ref to comparison function
  72                 goto fail_inner if &$size($fline, $tline);
  73             } else {
  74                 goto fail_inner if $fline ne $tline;
  75             }
  76         }
  77         goto fail_inner if defined($tline = <TO>);
  78     }
  79     else {
  80         unless (defined($size) && $size > 0) {
  81             $size = $fromsize || -s TO || 0;
  82             $size = 1024 if $size < 512;
  83             $size = $Too_Big if $size > $Too_Big;
  84         }
  85
  86         my ($fr,$tr,$fbuf,$tbuf);
  87         $fbuf = $tbuf = '';
  88         while(defined($fr = read(FROM,$fbuf,$size)) && $fr > 0) {
  89             unless (defined($tr = read(TO,$tbuf,$fr)) && $tbuf eq $fbuf) {
  90                 goto fail_inner;
  91             }
  92         }
  93         goto fail_inner if defined($tr = read(TO,$tbuf,$size)) && $tr > 0;
  94     }
  95
  96     close(TO) || goto fail_open2 if $closeto;
  97     close(FROM) || goto fail_open1 if $closefrom;
  98
  99     return 0;
 100
 101   # All of these contortions try to preserve error messages...
 102   fail_inner:
 103     close(TO) || goto fail_open2 if $closeto;
 104     close(FROM) || goto fail_open1 if $closefrom;
 105
 106     return 1;
 107
 108   fail_open2:
 109     if ($closefrom) {
 110         my $status = $!;
 111         $! = 0;
 112         close FROM;
 113         $! = $status unless $!;
 114     }
 115   fail_open1:
 116     return -1;
 117 }
 118
 119 sub cmp;
 120 *cmp = \&compare;
 121
 122 sub compare_text {
 123     my ($from,$to,$cmp) = @_;
 124     croak("Usage: compare_text( file1, file2 [, cmp-function])")
 125         unless @_ == 2 || @_ == 3;
 126     croak("Third arg to compare_text() function must be a code reference")
 127         if @_ == 3 && ref($cmp) ne 'CODE';
 128
 129     # Using a negative buffer size puts compare into text_mode too
 130     $cmp = -1 unless defined $cmp;
 131     compare($from, $to, $cmp);
 132 }
 133
 134 1;
 135
 136 __END__
 137
 138 =head1 NAME
 139
 140 File::Compare - Compare files or filehandles
 141
 142 =head1 SYNOPSIS
 143
 144         use File::Compare;
 145
 146         if (compare("file1","file2") == 0) {
 147             print "They're equal\n";
 148         }
 149
 150 =head1 DESCRIPTION
 151
 152 The File::Compare::compare function compares the contents of two
 153 sources, each of which can be a file or a file handle.  It is exported
 154 from File::Compare by default.
 155
 156 File::Compare::cmp is a synonym for File::Compare::compare.  It is
 157 exported from File::Compare only by request.
 158
 159 File::Compare::compare_text does a line by line comparison of the two
 160 files. It stops as soon as a difference is detected. compare_text()
 161 accepts an optional third argument: This must be a CODE reference to
 162 a line comparison function, which returns 0 when both lines are considered
 163 equal. For example:
 164
 165     compare_text($file1, $file2)
 166
 167 is basically equivalent to
 168
 169     compare_text($file1, $file2, sub {$_[0] ne $_[1]} )
 170
 171 =head1 RETURN
 172
 173 File::Compare::compare return 0 if the files are equal, 1 if the
 174 files are unequal, or -1 if an error was encountered.
 175
 176 =head1 AUTHOR
 177
 178 File::Compare was written by Nick Ing-Simmons.
 179 Its original documentation was written by Chip Salzenberg.
 180
 181 =cut
 182