1package TestCompare;
2
3use vars qw(@ISA @EXPORT $MYPKG);
4#use strict;
5#use diagnostics;
6use Carp;
7use Exporter;
8use File::Basename;
9use File::Spec;
10use FileHandle;
11
12@ISA = qw(Exporter);
13@EXPORT = qw(&testcmp);
14$MYPKG = eval { (caller)[0] };
15
16##--------------------------------------------------------------------------
17
18=head1 NAME
19
20testcmp -- compare two files line-by-line
21
22=head1 SYNOPSIS
23
24    $is_diff = testcmp($file1, $file2);
25
26or
27
28    $is_diff = testcmp({-cmplines => \&mycmp}, $file1, $file2);
29
30=head2 DESCRIPTION
31
32Compare two text files line-by-line and return 0 if they are the
33same, 1 if they differ. Each of $file1 and $file2 may be a filenames,
34or a filehandles (in which case it must already be open for reading).
35
36If the first argument is a hashref, then the B<-cmplines> key in the
37hash may have a subroutine reference as its corresponding value.
38The referenced user-defined subroutine should be a line-comparator
39function that takes two pre-chomped text-lines as its arguments
40(the first is from $file1 and the second is from $file2). It should
41return 0 if it considers the two lines equivalent, and non-zero
42otherwise.
43
44=cut
45
46##--------------------------------------------------------------------------
47
48sub testcmp( $ $ ; $) {
49   my %opts = ref($_[0]) eq 'HASH' ? %{shift()} : ();
50   my ($file1, $file2) = @_;
51   my ($fh1, $fh2) = ($file1, $file2);
52   unless (ref $fh1) {
53      $fh1 = FileHandle->new($file1, "r") or die "Can't open $file1: $!";
54   }
55   unless (ref $fh2) {
56      $fh2 = FileHandle->new($file2, "r") or die "Can't open $file2: $!";
57   }
58
59   my $cmplines = $opts{'-cmplines'} || undef;
60   my ($f1text, $f2text) = ("", "");
61   my ($line, $diffs)    = (0, 0);
62
63   while ( defined($f1text) and defined($f2text) ) {
64      defined($f1text = <$fh1>)  and  chomp($f1text);
65      defined($f2text = <$fh2>)  and  chomp($f2text);
66      ++$line;
67      last unless ( defined($f1text) and defined($f2text) );
68      # kill any extra line endings
69      $f1text =~ s/[\r\n]+$//s;
70      $f2text =~ s/[\r\n]+$//s;
71      $diffs = (ref $cmplines) ? &$cmplines($f1text, $f2text)
72                               : ($f1text ne $f2text);
73      last if $diffs;
74   }
75   close($fh1) unless (ref $file1);
76   close($fh2) unless (ref $file2);
77
78   $diffs = 1  if (defined($f1text) or defined($f2text));
79   if ( defined($f1text) and defined($f2text) ) {
80      ## these two lines must be different
81      warn "$file1 and $file2 differ at line $line\n";
82   }
83   elsif (defined($f1text)  and  (! defined($f1text))) {
84      ## file1 must be shorter
85      warn "$file1 is shorter than $file2\n";
86   }
87   elsif (defined $f2text) {
88      ## file2 must be longer
89      warn "$file1 is shorter than $file2\n";
90   }
91   return $diffs;
92}
93
941;
95