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1 | package File::Compare; |
2 | |
3 | use strict; |
4 | use vars qw($VERSION @ISA @EXPORT @EXPORT_OK $Too_Big *FROM *TO); |
5 | |
6 | require Exporter; |
7 | use Carp; |
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8 | |
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9 | $VERSION = '1.1001'; |
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10 | @ISA = qw(Exporter); |
11 | @EXPORT = qw(compare); |
12 | @EXPORT_OK = qw(cmp); |
13 | |
14 | $Too_Big = 1024 * 1024 * 2; |
15 | |
16 | sub VERSION { |
17 | # Version of File::Compare |
18 | return $File::Compare::VERSION; |
19 | } |
20 | |
21 | sub compare { |
22 | croak("Usage: compare( file1, file2 [, buffersize]) ") |
23 | unless(@_ == 2 || @_ == 3); |
24 | |
25 | my $from = shift; |
26 | my $to = shift; |
27 | my $closefrom=0; |
28 | my $closeto=0; |
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29 | my ($size, $fromsize, $status, $fr, $tr, $fbuf, $tbuf); |
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30 | local(*FROM, *TO); |
31 | local($\) = ''; |
32 | |
33 | croak("from undefined") unless (defined $from); |
34 | croak("to undefined") unless (defined $to); |
35 | |
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36 | if (ref($from) && |
37 | (UNIVERSAL::isa($from,'GLOB') || UNIVERSAL::isa($from,'IO::Handle'))) { |
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38 | *FROM = *$from; |
39 | } elsif (ref(\$from) eq 'GLOB') { |
40 | *FROM = $from; |
41 | } else { |
42 | open(FROM,"<$from") or goto fail_open1; |
43 | binmode FROM; |
44 | $closefrom = 1; |
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45 | $fromsize = -s FROM; |
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46 | } |
47 | |
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48 | if (ref($to) && |
49 | (UNIVERSAL::isa($to,'GLOB') || UNIVERSAL::isa($to,'IO::Handle'))) { |
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50 | *TO = *$to; |
51 | } elsif (ref(\$to) eq 'GLOB') { |
52 | *TO = $to; |
53 | } else { |
54 | open(TO,"<$to") or goto fail_open2; |
55 | binmode TO; |
56 | $closeto = 1; |
57 | } |
58 | |
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59 | if ($closefrom && $closeto) { |
60 | # If both are opened files we know they differ if their size differ |
61 | goto fail_inner if $fromsize != -s TO; |
62 | } |
63 | |
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64 | if (@_) { |
65 | $size = shift(@_) + 0; |
66 | croak("Bad buffer size for compare: $size\n") unless ($size > 0); |
67 | } else { |
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68 | $size = $fromsize; |
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69 | $size = 1024 if ($size < 512); |
70 | $size = $Too_Big if ($size > $Too_Big); |
71 | } |
72 | |
73 | $fbuf = ''; |
74 | $tbuf = ''; |
75 | while(defined($fr = read(FROM,$fbuf,$size)) && $fr > 0) { |
76 | unless (defined($tr = read(TO,$tbuf,$fr)) and $tbuf eq $fbuf) { |
77 | goto fail_inner; |
78 | } |
79 | } |
80 | goto fail_inner if (defined($tr = read(TO,$tbuf,$size)) && $tr > 0); |
81 | |
82 | close(TO) || goto fail_open2 if $closeto; |
83 | close(FROM) || goto fail_open1 if $closefrom; |
84 | |
85 | return 0; |
86 | |
87 | # All of these contortions try to preserve error messages... |
88 | fail_inner: |
89 | close(TO) || goto fail_open2 if $closeto; |
90 | close(FROM) || goto fail_open1 if $closefrom; |
91 | |
92 | return 1; |
93 | |
94 | fail_open2: |
95 | if ($closefrom) { |
96 | $status = $!; |
97 | $! = 0; |
98 | close FROM; |
99 | $! = $status unless $!; |
100 | } |
101 | fail_open1: |
102 | return -1; |
103 | } |
104 | |
105 | *cmp = \&compare; |
106 | |
107 | 1; |
108 | |
109 | __END__ |
110 | |
111 | =head1 NAME |
112 | |
113 | File::Compare - Compare files or filehandles |
114 | |
115 | =head1 SYNOPSIS |
116 | |
117 | use File::Compare; |
118 | |
119 | if (compare("file1","file2") == 0) { |
120 | print "They're equal\n"; |
121 | } |
122 | |
123 | =head1 DESCRIPTION |
124 | |
125 | The File::Compare::compare function compares the contents of two |
126 | sources, each of which can be a file or a file handle. It is exported |
127 | from File::Compare by default. |
128 | |
129 | File::Compare::cmp is a synonym for File::Compare::compare. It is |
130 | exported from File::Compare only by request. |
131 | |
132 | =head1 RETURN |
133 | |
134 | File::Compare::compare return 0 if the files are equal, 1 if the |
135 | files are unequal, or -1 if an error was encountered. |
136 | |
137 | =head1 AUTHOR |
138 | |
139 | File::Compare was written by Nick Ing-Simmons. |
140 | Its original documentation was written by Chip Salzenberg. |
141 | |
142 | =cut |
143 | |