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86530b38 AT |
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 | use Carp; | |
10 | ||
11 | $VERSION = '1.1003'; | |
12 | @ISA = qw(Exporter); | |
13 | @EXPORT = qw(compare); | |
14 | @EXPORT_OK = qw(cmp compare_text); | |
15 | ||
16 | $Too_Big = 1024 * 1024 * 2; | |
17 | ||
18 | sub compare { | |
19 | croak("Usage: compare( file1, file2 [, buffersize]) ") | |
20 | unless(@_ == 2 || @_ == 3); | |
21 | ||
22 | my ($from,$to,$size) = @_; | |
23 | my $text_mode = defined($size) && (ref($size) eq 'CODE' || $size < 0); | |
24 | ||
25 | my ($fromsize,$closefrom,$closeto); | |
26 | local (*FROM, *TO); | |
27 | ||
28 | croak("from undefined") unless (defined $from); | |
29 | croak("to undefined") unless (defined $to); | |
30 | ||
31 | if (ref($from) && | |
32 | (UNIVERSAL::isa($from,'GLOB') || UNIVERSAL::isa($from,'IO::Handle'))) { | |
33 | *FROM = *$from; | |
34 | } elsif (ref(\$from) eq 'GLOB') { | |
35 | *FROM = $from; | |
36 | } else { | |
37 | open(FROM,"<$from") or goto fail_open1; | |
38 | unless ($text_mode) { | |
39 | binmode FROM; | |
40 | $fromsize = -s FROM; | |
41 | } | |
42 | $closefrom = 1; | |
43 | } | |
44 | ||
45 | if (ref($to) && | |
46 | (UNIVERSAL::isa($to,'GLOB') || UNIVERSAL::isa($to,'IO::Handle'))) { | |
47 | *TO = *$to; | |
48 | } elsif (ref(\$to) eq 'GLOB') { | |
49 | *TO = $to; | |
50 | } else { | |
51 | open(TO,"<$to") or goto fail_open2; | |
52 | binmode TO unless $text_mode; | |
53 | $closeto = 1; | |
54 | } | |
55 | ||
56 | if (!$text_mode && $closefrom && $closeto) { | |
57 | # If both are opened files we know they differ if their size differ | |
58 | goto fail_inner if $fromsize != -s TO; | |
59 | } | |
60 | ||
61 | if ($text_mode) { | |
62 | local $/ = "\n"; | |
63 | my ($fline,$tline); | |
64 | while (defined($fline = <FROM>)) { | |
65 | goto fail_inner unless defined($tline = <TO>); | |
66 | if (ref $size) { | |
67 | # $size contains ref to comparison function | |
68 | goto fail_inner if &$size($fline, $tline); | |
69 | } else { | |
70 | goto fail_inner if $fline ne $tline; | |
71 | } | |
72 | } | |
73 | goto fail_inner if defined($tline = <TO>); | |
74 | } | |
75 | else { | |
76 | unless (defined($size) && $size > 0) { | |
77 | $size = $fromsize || -s TO || 0; | |
78 | $size = 1024 if $size < 512; | |
79 | $size = $Too_Big if $size > $Too_Big; | |
80 | } | |
81 | ||
82 | my ($fr,$tr,$fbuf,$tbuf); | |
83 | $fbuf = $tbuf = ''; | |
84 | while(defined($fr = read(FROM,$fbuf,$size)) && $fr > 0) { | |
85 | unless (defined($tr = read(TO,$tbuf,$fr)) && $tbuf eq $fbuf) { | |
86 | goto fail_inner; | |
87 | } | |
88 | } | |
89 | goto fail_inner if defined($tr = read(TO,$tbuf,$size)) && $tr > 0; | |
90 | } | |
91 | ||
92 | close(TO) || goto fail_open2 if $closeto; | |
93 | close(FROM) || goto fail_open1 if $closefrom; | |
94 | ||
95 | return 0; | |
96 | ||
97 | # All of these contortions try to preserve error messages... | |
98 | fail_inner: | |
99 | close(TO) || goto fail_open2 if $closeto; | |
100 | close(FROM) || goto fail_open1 if $closefrom; | |
101 | ||
102 | return 1; | |
103 | ||
104 | fail_open2: | |
105 | if ($closefrom) { | |
106 | my $status = $!; | |
107 | $! = 0; | |
108 | close FROM; | |
109 | $! = $status unless $!; | |
110 | } | |
111 | fail_open1: | |
112 | return -1; | |
113 | } | |
114 | ||
115 | sub cmp; | |
116 | *cmp = \&compare; | |
117 | ||
118 | sub compare_text { | |
119 | my ($from,$to,$cmp) = @_; | |
120 | croak("Usage: compare_text( file1, file2 [, cmp-function])") | |
121 | unless @_ == 2 || @_ == 3; | |
122 | croak("Third arg to compare_text() function must be a code reference") | |
123 | if @_ == 3 && ref($cmp) ne 'CODE'; | |
124 | ||
125 | # Using a negative buffer size puts compare into text_mode too | |
126 | $cmp = -1 unless defined $cmp; | |
127 | compare($from, $to, $cmp); | |
128 | } | |
129 | ||
130 | 1; | |
131 | ||
132 | __END__ | |
133 | ||
134 | =head1 NAME | |
135 | ||
136 | File::Compare - Compare files or filehandles | |
137 | ||
138 | =head1 SYNOPSIS | |
139 | ||
140 | use File::Compare; | |
141 | ||
142 | if (compare("file1","file2") == 0) { | |
143 | print "They're equal\n"; | |
144 | } | |
145 | ||
146 | =head1 DESCRIPTION | |
147 | ||
148 | The File::Compare::compare function compares the contents of two | |
149 | sources, each of which can be a file or a file handle. It is exported | |
150 | from File::Compare by default. | |
151 | ||
152 | File::Compare::cmp is a synonym for File::Compare::compare. It is | |
153 | exported from File::Compare only by request. | |
154 | ||
155 | File::Compare::compare_text does a line by line comparison of the two | |
156 | files. It stops as soon as a difference is detected. compare_text() | |
157 | accepts an optional third argument: This must be a CODE reference to | |
158 | a line comparison function, which returns 0 when both lines are considered | |
159 | equal. For example: | |
160 | ||
161 | compare_text($file1, $file2) | |
162 | ||
163 | is basically equivalent to | |
164 | ||
165 | compare_text($file1, $file2, sub {$_[0] ne $_[1]} ) | |
166 | ||
167 | =head1 RETURN | |
168 | ||
169 | File::Compare::compare and its sibling functions return 0 if the files | |
170 | are equal, 1 if the files are unequal, or -1 if an error was encountered. | |
171 | ||
172 | =head1 AUTHOR | |
173 | ||
174 | File::Compare was written by Nick Ing-Simmons. | |
175 | Its original documentation was written by Chip Salzenberg. | |
176 | ||
177 | =cut | |
178 |