source: trunk/essentials/sys-devel/automake-1.9/lib/Automake/FileUtils.pm

Last change on this file was 3086, checked in by bird, 18 years ago

automake 1.9.6

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1# Copyright (C) 2003, 2004, 2005 Free Software Foundation, Inc.
2
3# This program is free software; you can redistribute it and/or modify
4# it under the terms of the GNU General Public License as published by
5# the Free Software Foundation; either version 2, or (at your option)
6# any later version.
7
8# This program is distributed in the hope that it will be useful,
9# but WITHOUT ANY WARRANTY; without even the implied warranty of
10# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11# GNU General Public License for more details.
12
13# You should have received a copy of the GNU General Public License
14# along with this program; if not, write to the Free Software
15# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
16# 02110-1301, USA.
17
18package Automake::FileUtils;
19
20=head1 NAME
21
22Automake::FileUtils - handling files
23
24=head1 SYNOPSIS
25
26 use Automake::FileUtils
27
28=head1 DESCRIPTION
29
30This perl module provides various general purpose file handling functions.
31
32=cut
33
34use strict;
35use Exporter;
36use File::stat;
37use IO::File;
38use Automake::Channels;
39use Automake::ChannelDefs;
40
41use vars qw (@ISA @EXPORT);
42
43@ISA = qw (Exporter);
44@EXPORT = qw (&contents
45 &find_file &mtime
46 &update_file &up_to_date_p
47 &xsystem &xqx &dir_has_case_matching_file &reset_dir_cache);
48
49
50=item C<find_file ($file_name, @include)>
51
52Return the first path for a C<$file_name> in the C<include>s.
53
54We match exactly the behavior of GNU M4: first look in the current
55directory (which includes the case of absolute file names), and, if
56the file is not absolute, just fail. Otherwise, look in C<@include>.
57
58If the file is flagged as optional (ends with C<?>), then return undef
59if absent, otherwise exit with error.
60
61=cut
62
63# $FILE_NAME
64# find_file ($FILE_NAME, @INCLUDE)
65# -------------------------------
66sub find_file ($@)
67{
68 use File::Spec;
69
70 my ($file_name, @include) = @_;
71 my $optional = 0;
72
73 $optional = 1
74 if $file_name =~ s/\?$//;
75
76 return File::Spec->canonpath ($file_name)
77 if -e $file_name;
78
79 if (File::Spec->file_name_is_absolute ($file_name))
80 {
81 fatal "$file_name: no such file or directory"
82 unless $optional;
83 return undef;
84 }
85
86 foreach my $path (@include)
87 {
88 return File::Spec->canonpath (File::Spec->catfile ($path, $file_name))
89 if -e File::Spec->catfile ($path, $file_name)
90 }
91
92 fatal "$file_name: no such file or directory"
93 unless $optional;
94
95 return undef;
96}
97
98=item C<mtime ($file)>
99
100Return the mtime of C<$file>. Missing files, or C<-> standing for
101C<STDIN> or C<STDOUT> are ``obsolete'', i.e., as old as possible.
102
103=cut
104
105# $MTIME
106# MTIME ($FILE)
107# -------------
108sub mtime ($)
109{
110 my ($file) = @_;
111
112 return 0
113 if $file eq '-' || ! -f $file;
114
115 my $stat = stat ($file)
116 or fatal "cannot stat $file: $!";
117
118 return $stat->mtime;
119}
120
121
122=item C<update_file ($from, $to, [$force])>
123
124Rename C<$from> as C<$to>, preserving C<$to> timestamp if it has not
125changed, unless C<$force> is true (defaults to false). Recognize
126C<$to> = C<-> standing for C<STDIN>. C<$from> is always
127removed/renamed.
128
129=cut
130
131# &update_file ($FROM, $TO; $FORCE)
132# ---------------------------------
133sub update_file ($$;$)
134{
135 my ($from, $to, $force) = @_;
136 $force = 0
137 unless defined $force;
138 my $SIMPLE_BACKUP_SUFFIX = $ENV{'SIMPLE_BACKUP_SUFFIX'} || '~';
139 use File::Compare;
140 use File::Copy;
141
142 if ($to eq '-')
143 {
144 my $in = new IO::File ("$from");
145 my $out = new IO::File (">-");
146 while ($_ = $in->getline)
147 {
148 print $out $_;
149 }
150 $in->close;
151 unlink ($from) || fatal "cannot remove $from: $!";
152 return;
153 }
154
155 if (!$force && -f "$to" && compare ("$from", "$to") == 0)
156 {
157 # File didn't change, so don't update its mod time.
158 msg 'note', "`$to' is unchanged";
159 unlink ($from)
160 or fatal "cannot remove $from: $!";
161 return
162 }
163
164 if (-f "$to")
165 {
166 # Back up and install the new one.
167 move ("$to", "$to$SIMPLE_BACKUP_SUFFIX")
168 or fatal "cannot backup $to: $!";
169 move ("$from", "$to")
170 or fatal "cannot rename $from as $to: $!";
171 msg 'note', "`$to' is updated";
172 }
173 else
174 {
175 move ("$from", "$to")
176 or fatal "cannot rename $from as $to: $!";
177 msg 'note', "`$to' is created";
178 }
179}
180
181
182=item C<up_to_date_p ($file, @dep)>
183
184Is C<$file> more recent than C<@dep>?
185
186=cut
187
188# $BOOLEAN
189# &up_to_date_p ($FILE, @DEP)
190# ---------------------------
191sub up_to_date_p ($@)
192{
193 my ($file, @dep) = @_;
194 my $mtime = mtime ($file);
195
196 foreach my $dep (@dep)
197 {
198 if ($mtime < mtime ($dep))
199 {
200 verb "up_to_date ($file): outdated: $dep";
201 return 0;
202 }
203 }
204
205 verb "up_to_date ($file): up to date";
206 return 1;
207}
208
209
210=item C<handle_exec_errors ($command)>
211
212Display an error message for C<$command>, based on the content of
213C<$?> and C<$!>.
214
215=cut
216
217# handle_exec_errors ($COMMAND)
218# -----------------------------
219sub handle_exec_errors ($)
220{
221 my ($command) = @_;
222
223 $command = (split (' ', $command))[0];
224 if ($!)
225 {
226 fatal "failed to run $command: $!";
227 }
228 else
229 {
230 use POSIX qw (WIFEXITED WEXITSTATUS WIFSIGNALED WTERMSIG);
231
232 if (WIFEXITED ($?))
233 {
234 my $status = WEXITSTATUS ($?);
235 # Propagate exit codes.
236 fatal ('',
237 "$command failed with exit status: $status",
238 exit_code => $status);
239 }
240 elsif (WIFSIGNALED ($?))
241 {
242 my $signal = WTERMSIG ($?);
243 fatal "$command terminated by signal: $signal";
244 }
245 else
246 {
247 fatal "$command exited abnormally";
248 }
249 }
250}
251
252=item C<xqx ($command)>
253
254Same as C<qx> (but in scalar context), but fails on errors.
255
256=cut
257
258# xqx ($COMMAND)
259# --------------
260sub xqx ($)
261{
262 my ($command) = @_;
263
264 verb "running: $command";
265
266 $! = 0;
267 my $res = `$command`;
268 handle_exec_errors $command
269 if $?;
270
271 return $res;
272}
273
274
275=item C<xsystem ($command)>
276
277Same as C<system>, but fails on errors, and reports the C<$command>
278in verbose mode.
279
280=cut
281
282# xsystem ($COMMAND)
283# ------------------
284sub xsystem ($)
285{
286 my ($command) = @_;
287
288 verb "running: $command";
289
290 $! = 0;
291 handle_exec_errors $command
292 if system $command;
293}
294
295
296=item C<contents ($file_name)>
297
298Return the contents of C<$file_name>.
299
300=cut
301
302# contents ($FILE_NAME)
303# ---------------------
304sub contents ($)
305{
306 my ($file) = @_;
307 verb "reading $file";
308 local $/; # Turn on slurp-mode.
309 my $f = new Automake::XFile "< $file";
310 my $contents = $f->getline;
311 $f->close;
312 return $contents;
313}
314
315
316=item C<dir_has_case_matching_file ($DIRNAME, $FILE_NAME)>
317
318Return true iff $DIR contains a file name that matches $FILE_NAME case
319insensitively.
320
321We need to be cautious on case-insensitive case-preserving file
322systems (e.g. Mac OS X's HFS+). On such systems C<-f 'Foo'> and C<-f
323'foO'> answer the same thing. Hence if a package distributes its own
324F<CHANGELOG> file, but has no F<ChangeLog> file, automake would still
325try to distribute F<ChangeLog> (because it thinks it exists) in
326addition to F<CHANGELOG>, although it is impossible for these two
327files to be in the same directory (the two file names designate the
328same file).
329
330=cut
331
332use vars '%_directory_cache';
333sub dir_has_case_matching_file ($$)
334{
335 # Note that print File::Spec->case_tolerant returns 0 even on MacOS
336 # X (with Perl v5.8.1-RC3 at least), so do not try to shortcut this
337 # function using that.
338
339 my ($dirname, $file_name) = @_;
340 return 0 unless -f "$dirname/$file_name";
341
342 # The file appears to exist, however it might be a mirage if the
343 # system is case insensitive. Let's browse the directory and check
344 # whether the file is really in. We maintain a cache of directories
345 # so Automake doesn't spend all its time reading the same directory
346 # again and again.
347 if (!exists $_directory_cache{$dirname})
348 {
349 error "failed to open directory `$dirname'"
350 unless opendir (DIR, $dirname);
351 $_directory_cache{$dirname} = { map { $_ => 1 } readdir (DIR) };
352 closedir (DIR);
353 }
354 return exists $_directory_cache{$dirname}{$file_name};
355}
356
357=item C<reset_dir_cache ($dirname)>
358
359Clear C<dir_has_case_matching_file>'s cache for C<$dirname>.
360
361=cut
362
363sub reset_dir_cache ($)
364{
365 delete $_directory_cache{$_[0]};
366}
367
3681; # for require
369
370### Setup "GNU" style for perl-mode and cperl-mode.
371## Local Variables:
372## perl-indent-level: 2
373## perl-continued-statement-offset: 2
374## perl-continued-brace-offset: 0
375## perl-brace-offset: 0
376## perl-brace-imaginary-offset: 0
377## perl-label-offset: -2
378## cperl-indent-level: 2
379## cperl-brace-offset: 0
380## cperl-continued-brace-offset: 0
381## cperl-label-offset: -2
382## cperl-extra-newline-before-brace: t
383## cperl-merge-trailing-else: nil
384## cperl-continued-statement-offset: 2
385## End:
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