[Summary view] [Print] [Text view]

   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  
  10  $VERSION = '1.1005';
  11  @ISA = qw(Exporter);
  12  @EXPORT = qw(compare);
  13  @EXPORT_OK = qw(cmp compare_text);
  14  
  15  $Too_Big = 1024 * 1024 * 2;
  16  
  17  sub croak {
  18      require Carp;
  19      goto &Carp::croak;
  20  }
  21  
  22  sub compare {
  23      croak("Usage: compare( file1, file2 [, buffersize]) ")
  24        unless(@_ == 2 || @_ == 3);
  25  
  26      my ($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 and its sibling functions return 0 if the files
 174  are equal, 1 if the 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