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1 | package File::Temp; |
2 | ||
3 | =head1 NAME | |
4 | ||
5 | File::Temp - return name and handle of a temporary file safely | |
6 | ||
7 | =begin __INTERNALS | |
8 | ||
9 | =head1 PORTABILITY | |
10 | ||
11 | This section is at the top in order to provide easier access to | |
12 | porters. It is not expected to be rendered by a standard pod | |
13 | formatting tool. Please skip straight to the SYNOPSIS section if you | |
14 | are not trying to port this module to a new platform. | |
15 | ||
16 | This module is designed to be portable across operating systems and it | |
17 | currently supports Unix, VMS, DOS, OS/2, Windows and Mac OS | |
18 | (Classic). When porting to a new OS there are generally three main | |
19 | issues that have to be solved: | |
20 | ||
21 | =over 4 | |
22 | ||
23 | =item * | |
24 | ||
25 | Can the OS unlink an open file? If it can not then the | |
26 | C<_can_unlink_opened_file> method should be modified. | |
27 | ||
28 | =item * | |
29 | ||
30 | Are the return values from C<stat> reliable? By default all the | |
31 | return values from C<stat> are compared when unlinking a temporary | |
32 | file using the filename and the handle. Operating systems other than | |
33 | unix do not always have valid entries in all fields. If C<unlink0> fails | |
34 | then the C<stat> comparison should be modified accordingly. | |
35 | ||
36 | =item * | |
37 | ||
38 | Security. Systems that can not support a test for the sticky bit | |
39 | on a directory can not use the MEDIUM and HIGH security tests. | |
40 | The C<_can_do_level> method should be modified accordingly. | |
41 | ||
42 | =back | |
43 | ||
44 | =end __INTERNALS | |
45 | ||
46 | =head1 SYNOPSIS | |
47 | ||
48 | use File::Temp qw/ tempfile tempdir /; | |
49 | ||
50 | $fh = tempfile(); | |
51 | ($fh, $filename) = tempfile(); | |
52 | ||
53 | ($fh, $filename) = tempfile( $template, DIR => $dir); | |
54 | ($fh, $filename) = tempfile( $template, SUFFIX => '.dat'); | |
55 | ||
56 | ||
57 | $dir = tempdir( CLEANUP => 1 ); | |
58 | ($fh, $filename) = tempfile( DIR => $dir ); | |
59 | ||
60 | Object interface: | |
61 | ||
62 | require File::Temp; | |
63 | use File::Temp (); | |
64 | ||
65 | $fh = new File::Temp($template); | |
66 | $fname = $fh->filename; | |
67 | ||
68 | $tmp = new File::Temp( UNLINK => 0, SUFFIX => '.dat' ); | |
69 | print $tmp "Some data\n"; | |
70 | print "Filename is $tmp\n"; | |
71 | ||
72 | The following interfaces are provided for compatibility with | |
73 | existing APIs. They should not be used in new code. | |
74 | ||
75 | MkTemp family: | |
76 | ||
77 | use File::Temp qw/ :mktemp /; | |
78 | ||
79 | ($fh, $file) = mkstemp( "tmpfileXXXXX" ); | |
80 | ($fh, $file) = mkstemps( "tmpfileXXXXXX", $suffix); | |
81 | ||
82 | $tmpdir = mkdtemp( $template ); | |
83 | ||
84 | $unopened_file = mktemp( $template ); | |
85 | ||
86 | POSIX functions: | |
87 | ||
88 | use File::Temp qw/ :POSIX /; | |
89 | ||
90 | $file = tmpnam(); | |
91 | $fh = tmpfile(); | |
92 | ||
93 | ($fh, $file) = tmpnam(); | |
94 | ||
95 | Compatibility functions: | |
96 | ||
97 | $unopened_file = File::Temp::tempnam( $dir, $pfx ); | |
98 | ||
99 | =head1 DESCRIPTION | |
100 | ||
101 | C<File::Temp> can be used to create and open temporary files in a safe | |
102 | way. There is both a function interface and an object-oriented | |
103 | interface. The File::Temp constructor or the tempfile() function can | |
104 | be used to return the name and the open filehandle of a temporary | |
105 | file. The tempdir() function can be used to create a temporary | |
106 | directory. | |
107 | ||
108 | The security aspect of temporary file creation is emphasized such that | |
109 | a filehandle and filename are returned together. This helps guarantee | |
110 | that a race condition can not occur where the temporary file is | |
111 | created by another process between checking for the existence of the | |
112 | file and its opening. Additional security levels are provided to | |
113 | check, for example, that the sticky bit is set on world writable | |
114 | directories. See L<"safe_level"> for more information. | |
115 | ||
116 | For compatibility with popular C library functions, Perl implementations of | |
117 | the mkstemp() family of functions are provided. These are, mkstemp(), | |
118 | mkstemps(), mkdtemp() and mktemp(). | |
119 | ||
120 | Additionally, implementations of the standard L<POSIX|POSIX> | |
121 | tmpnam() and tmpfile() functions are provided if required. | |
122 | ||
123 | Implementations of mktemp(), tmpnam(), and tempnam() are provided, | |
124 | but should be used with caution since they return only a filename | |
125 | that was valid when function was called, so cannot guarantee | |
126 | that the file will not exist by the time the caller opens the filename. | |
127 | ||
128 | =cut | |
129 | ||
130 | # 5.6.0 gives us S_IWOTH, S_IWGRP, our and auto-vivifying filehandls | |
131 | # People would like a version on 5.005 so give them what they want :-) | |
132 | use 5.005; | |
133 | use strict; | |
134 | use Carp; | |
135 | use File::Spec 0.8; | |
136 | use File::Path qw/ rmtree /; | |
137 | use Fcntl 1.03; | |
138 | use Errno; | |
139 | require VMS::Stdio if $^O eq 'VMS'; | |
140 | ||
141 | # Need the Symbol package if we are running older perl | |
142 | require Symbol if $] < 5.006; | |
143 | ||
144 | ### For the OO interface | |
145 | use base qw/ IO::Handle /; | |
146 | use overload '""' => "STRINGIFY"; | |
147 | ||
148 | ||
149 | # use 'our' on v5.6.0 | |
150 | use vars qw($VERSION @EXPORT_OK %EXPORT_TAGS $DEBUG $KEEP_ALL); | |
151 | ||
152 | $DEBUG = 0; | |
153 | $KEEP_ALL = 0; | |
154 | ||
155 | # We are exporting functions | |
156 | ||
157 | use base qw/Exporter/; | |
158 | ||
159 | # Export list - to allow fine tuning of export table | |
160 | ||
161 | @EXPORT_OK = qw{ | |
162 | tempfile | |
163 | tempdir | |
164 | tmpnam | |
165 | tmpfile | |
166 | mktemp | |
167 | mkstemp | |
168 | mkstemps | |
169 | mkdtemp | |
170 | unlink0 | |
171 | cleanup | |
172 | }; | |
173 | ||
174 | # Groups of functions for export | |
175 | ||
176 | %EXPORT_TAGS = ( | |
177 | 'POSIX' => [qw/ tmpnam tmpfile /], | |
178 | 'mktemp' => [qw/ mktemp mkstemp mkstemps mkdtemp/], | |
179 | ); | |
180 | ||
181 | # add contents of these tags to @EXPORT | |
182 | Exporter::export_tags('POSIX','mktemp'); | |
183 | ||
184 | # Version number | |
185 | ||
186 | $VERSION = '0.16'; | |
187 | ||
188 | # This is a list of characters that can be used in random filenames | |
189 | ||
190 | my @CHARS = (qw/ A B C D E F G H I J K L M N O P Q R S T U V W X Y Z | |
191 | a b c d e f g h i j k l m n o p q r s t u v w x y z | |
192 | 0 1 2 3 4 5 6 7 8 9 _ | |
193 | /); | |
194 | ||
195 | # Maximum number of tries to make a temp file before failing | |
196 | ||
197 | use constant MAX_TRIES => 1000; | |
198 | ||
199 | # Minimum number of X characters that should be in a template | |
200 | use constant MINX => 4; | |
201 | ||
202 | # Default template when no template supplied | |
203 | ||
204 | use constant TEMPXXX => 'X' x 10; | |
205 | ||
206 | # Constants for the security level | |
207 | ||
208 | use constant STANDARD => 0; | |
209 | use constant MEDIUM => 1; | |
210 | use constant HIGH => 2; | |
211 | ||
212 | # OPENFLAGS. If we defined the flag to use with Sysopen here this gives | |
213 | # us an optimisation when many temporary files are requested | |
214 | ||
215 | my $OPENFLAGS = O_CREAT | O_EXCL | O_RDWR; | |
216 | ||
217 | unless ($^O eq 'MacOS') { | |
218 | for my $oflag (qw/ NOFOLLOW BINARY LARGEFILE EXLOCK NOINHERIT /) { | |
219 | my ($bit, $func) = (0, "Fcntl::O_" . $oflag); | |
220 | no strict 'refs'; | |
221 | $OPENFLAGS |= $bit if eval { | |
222 | # Make sure that redefined die handlers do not cause problems | |
223 | # eg CGI::Carp | |
224 | local $SIG{__DIE__} = sub {}; | |
225 | local $SIG{__WARN__} = sub {}; | |
226 | $bit = &$func(); | |
227 | 1; | |
228 | }; | |
229 | } | |
230 | } | |
231 | ||
232 | # On some systems the O_TEMPORARY flag can be used to tell the OS | |
233 | # to automatically remove the file when it is closed. This is fine | |
234 | # in most cases but not if tempfile is called with UNLINK=>0 and | |
235 | # the filename is requested -- in the case where the filename is to | |
236 | # be passed to another routine. This happens on windows. We overcome | |
237 | # this by using a second open flags variable | |
238 | ||
239 | my $OPENTEMPFLAGS = $OPENFLAGS; | |
240 | unless ($^O eq 'MacOS') { | |
241 | for my $oflag (qw/ TEMPORARY /) { | |
242 | my ($bit, $func) = (0, "Fcntl::O_" . $oflag); | |
243 | no strict 'refs'; | |
244 | $OPENTEMPFLAGS |= $bit if eval { | |
245 | # Make sure that redefined die handlers do not cause problems | |
246 | # eg CGI::Carp | |
247 | local $SIG{__DIE__} = sub {}; | |
248 | local $SIG{__WARN__} = sub {}; | |
249 | $bit = &$func(); | |
250 | 1; | |
251 | }; | |
252 | } | |
253 | } | |
254 | ||
255 | # INTERNAL ROUTINES - not to be used outside of package | |
256 | ||
257 | # Generic routine for getting a temporary filename | |
258 | # modelled on OpenBSD _gettemp() in mktemp.c | |
259 | ||
260 | # The template must contain X's that are to be replaced | |
261 | # with the random values | |
262 | ||
263 | # Arguments: | |
264 | ||
265 | # TEMPLATE - string containing the XXXXX's that is converted | |
266 | # to a random filename and opened if required | |
267 | ||
268 | # Optionally, a hash can also be supplied containing specific options | |
269 | # "open" => if true open the temp file, else just return the name | |
270 | # default is 0 | |
271 | # "mkdir"=> if true, we are creating a temp directory rather than tempfile | |
272 | # default is 0 | |
273 | # "suffixlen" => number of characters at end of PATH to be ignored. | |
274 | # default is 0. | |
275 | # "unlink_on_close" => indicates that, if possible, the OS should remove | |
276 | # the file as soon as it is closed. Usually indicates | |
277 | # use of the O_TEMPORARY flag to sysopen. | |
278 | # Usually irrelevant on unix | |
279 | ||
280 | # Optionally a reference to a scalar can be passed into the function | |
281 | # On error this will be used to store the reason for the error | |
282 | # "ErrStr" => \$errstr | |
283 | ||
284 | # "open" and "mkdir" can not both be true | |
285 | # "unlink_on_close" is not used when "mkdir" is true. | |
286 | ||
287 | # The default options are equivalent to mktemp(). | |
288 | ||
289 | # Returns: | |
290 | # filehandle - open file handle (if called with doopen=1, else undef) | |
291 | # temp name - name of the temp file or directory | |
292 | ||
293 | # For example: | |
294 | # ($fh, $name) = _gettemp($template, "open" => 1); | |
295 | ||
296 | # for the current version, failures are associated with | |
297 | # stored in an error string and returned to give the reason whilst debugging | |
298 | # This routine is not called by any external function | |
299 | sub _gettemp { | |
300 | ||
301 | croak 'Usage: ($fh, $name) = _gettemp($template, OPTIONS);' | |
302 | unless scalar(@_) >= 1; | |
303 | ||
304 | # the internal error string - expect it to be overridden | |
305 | # Need this in case the caller decides not to supply us a value | |
306 | # need an anonymous scalar | |
307 | my $tempErrStr; | |
308 | ||
309 | # Default options | |
310 | my %options = ( | |
311 | "open" => 0, | |
312 | "mkdir" => 0, | |
313 | "suffixlen" => 0, | |
314 | "unlink_on_close" => 0, | |
315 | "ErrStr" => \$tempErrStr, | |
316 | ); | |
317 | ||
318 | # Read the template | |
319 | my $template = shift; | |
320 | if (ref($template)) { | |
321 | # Use a warning here since we have not yet merged ErrStr | |
322 | carp "File::Temp::_gettemp: template must not be a reference"; | |
323 | return (); | |
324 | } | |
325 | ||
326 | # Check that the number of entries on stack are even | |
327 | if (scalar(@_) % 2 != 0) { | |
328 | # Use a warning here since we have not yet merged ErrStr | |
329 | carp "File::Temp::_gettemp: Must have even number of options"; | |
330 | return (); | |
331 | } | |
332 | ||
333 | # Read the options and merge with defaults | |
334 | %options = (%options, @_) if @_; | |
335 | ||
336 | # Make sure the error string is set to undef | |
337 | ${$options{ErrStr}} = undef; | |
338 | ||
339 | # Can not open the file and make a directory in a single call | |
340 | if ($options{"open"} && $options{"mkdir"}) { | |
341 | ${$options{ErrStr}} = "doopen and domkdir can not both be true\n"; | |
342 | return (); | |
343 | } | |
344 | ||
345 | # Find the start of the end of the Xs (position of last X) | |
346 | # Substr starts from 0 | |
347 | my $start = length($template) - 1 - $options{"suffixlen"}; | |
348 | ||
349 | # Check that we have at least MINX x X (eg 'XXXX") at the end of the string | |
350 | # (taking suffixlen into account). Any fewer is insecure. | |
351 | ||
352 | # Do it using substr - no reason to use a pattern match since | |
353 | # we know where we are looking and what we are looking for | |
354 | ||
355 | if (substr($template, $start - MINX + 1, MINX) ne 'X' x MINX) { | |
356 | ${$options{ErrStr}} = "The template must end with at least ". | |
357 | MINX . " 'X' characters\n"; | |
358 | return (); | |
359 | } | |
360 | ||
361 | # Replace all the X at the end of the substring with a | |
362 | # random character or just all the XX at the end of a full string. | |
363 | # Do it as an if, since the suffix adjusts which section to replace | |
364 | # and suffixlen=0 returns nothing if used in the substr directly | |
365 | # and generate a full path from the template | |
366 | ||
367 | my $path = _replace_XX($template, $options{"suffixlen"}); | |
368 | ||
369 | ||
370 | # Split the path into constituent parts - eventually we need to check | |
371 | # whether the directory exists | |
372 | # We need to know whether we are making a temp directory | |
373 | # or a tempfile | |
374 | ||
375 | my ($volume, $directories, $file); | |
376 | my $parent; # parent directory | |
377 | if ($options{"mkdir"}) { | |
378 | # There is no filename at the end | |
379 | ($volume, $directories, $file) = File::Spec->splitpath( $path, 1); | |
380 | ||
381 | # The parent is then $directories without the last directory | |
382 | # Split the directory and put it back together again | |
383 | my @dirs = File::Spec->splitdir($directories); | |
384 | ||
385 | # If @dirs only has one entry (i.e. the directory template) that means | |
386 | # we are in the current directory | |
387 | if ($#dirs == 0) { | |
388 | $parent = File::Spec->curdir; | |
389 | } else { | |
390 | ||
391 | if ($^O eq 'VMS') { # need volume to avoid relative dir spec | |
392 | $parent = File::Spec->catdir($volume, @dirs[0..$#dirs-1]); | |
393 | $parent = 'sys$disk:[]' if $parent eq ''; | |
394 | } else { | |
395 | ||
396 | # Put it back together without the last one | |
397 | $parent = File::Spec->catdir(@dirs[0..$#dirs-1]); | |
398 | ||
399 | # ...and attach the volume (no filename) | |
400 | $parent = File::Spec->catpath($volume, $parent, ''); | |
401 | } | |
402 | ||
403 | } | |
404 | ||
405 | } else { | |
406 | ||
407 | # Get rid of the last filename (use File::Basename for this?) | |
408 | ($volume, $directories, $file) = File::Spec->splitpath( $path ); | |
409 | ||
410 | # Join up without the file part | |
411 | $parent = File::Spec->catpath($volume,$directories,''); | |
412 | ||
413 | # If $parent is empty replace with curdir | |
414 | $parent = File::Spec->curdir | |
415 | unless $directories ne ''; | |
416 | ||
417 | } | |
418 | ||
419 | # Check that the parent directories exist | |
420 | # Do this even for the case where we are simply returning a name | |
421 | # not a file -- no point returning a name that includes a directory | |
422 | # that does not exist or is not writable | |
423 | ||
424 | unless (-d $parent) { | |
425 | ${$options{ErrStr}} = "Parent directory ($parent) is not a directory"; | |
426 | return (); | |
427 | } | |
428 | unless (-w $parent) { | |
429 | ${$options{ErrStr}} = "Parent directory ($parent) is not writable\n"; | |
430 | return (); | |
431 | } | |
432 | ||
433 | ||
434 | # Check the stickiness of the directory and chown giveaway if required | |
435 | # If the directory is world writable the sticky bit | |
436 | # must be set | |
437 | ||
438 | if (File::Temp->safe_level == MEDIUM) { | |
439 | my $safeerr; | |
440 | unless (_is_safe($parent,\$safeerr)) { | |
441 | ${$options{ErrStr}} = "Parent directory ($parent) is not safe ($safeerr)"; | |
442 | return (); | |
443 | } | |
444 | } elsif (File::Temp->safe_level == HIGH) { | |
445 | my $safeerr; | |
446 | unless (_is_verysafe($parent, \$safeerr)) { | |
447 | ${$options{ErrStr}} = "Parent directory ($parent) is not safe ($safeerr)"; | |
448 | return (); | |
449 | } | |
450 | } | |
451 | ||
452 | ||
453 | # Now try MAX_TRIES time to open the file | |
454 | for (my $i = 0; $i < MAX_TRIES; $i++) { | |
455 | ||
456 | # Try to open the file if requested | |
457 | if ($options{"open"}) { | |
458 | my $fh; | |
459 | ||
460 | # If we are running before perl5.6.0 we can not auto-vivify | |
461 | if ($] < 5.006) { | |
462 | $fh = &Symbol::gensym; | |
463 | } | |
464 | ||
465 | # Try to make sure this will be marked close-on-exec | |
466 | # XXX: Win32 doesn't respect this, nor the proper fcntl, | |
467 | # but may have O_NOINHERIT. This may or may not be in Fcntl. | |
468 | local $^F = 2; | |
469 | ||
470 | # Store callers umask | |
471 | my $umask = umask(); | |
472 | ||
473 | # Set a known umask | |
474 | umask(066); | |
475 | ||
476 | # Attempt to open the file | |
477 | my $open_success = undef; | |
478 | if ( $^O eq 'VMS' and $options{"unlink_on_close"} && !$KEEP_ALL) { | |
479 | # make it auto delete on close by setting FAB$V_DLT bit | |
480 | $fh = VMS::Stdio::vmssysopen($path, $OPENFLAGS, 0600, 'fop=dlt'); | |
481 | $open_success = $fh; | |
482 | } else { | |
483 | my $flags = ( ($options{"unlink_on_close"} && !$KEEP_ALL) ? | |
484 | $OPENTEMPFLAGS : | |
485 | $OPENFLAGS ); | |
486 | $open_success = sysopen($fh, $path, $flags, 0600); | |
487 | } | |
488 | if ( $open_success ) { | |
489 | ||
490 | # Reset umask | |
491 | umask($umask) if defined $umask; | |
492 | ||
493 | # Opened successfully - return file handle and name | |
494 | return ($fh, $path); | |
495 | ||
496 | } else { | |
497 | # Reset umask | |
498 | umask($umask) if defined $umask; | |
499 | ||
500 | # Error opening file - abort with error | |
501 | # if the reason was anything but EEXIST | |
502 | unless ($!{EEXIST}) { | |
503 | ${$options{ErrStr}} = "Could not create temp file $path: $!"; | |
504 | return (); | |
505 | } | |
506 | ||
507 | # Loop round for another try | |
508 | ||
509 | } | |
510 | } elsif ($options{"mkdir"}) { | |
511 | ||
512 | # Store callers umask | |
513 | my $umask = umask(); | |
514 | ||
515 | # Set a known umask | |
516 | umask(066); | |
517 | ||
518 | # Open the temp directory | |
519 | if (mkdir( $path, 0700)) { | |
520 | # created okay | |
521 | # Reset umask | |
522 | umask($umask) if defined $umask; | |
523 | ||
524 | return undef, $path; | |
525 | } else { | |
526 | ||
527 | # Reset umask | |
528 | umask($umask) if defined $umask; | |
529 | ||
530 | # Abort with error if the reason for failure was anything | |
531 | # except EEXIST | |
532 | unless ($!{EEXIST}) { | |
533 | ${$options{ErrStr}} = "Could not create directory $path: $!"; | |
534 | return (); | |
535 | } | |
536 | ||
537 | # Loop round for another try | |
538 | ||
539 | } | |
540 | ||
541 | } else { | |
542 | ||
543 | # Return true if the file can not be found | |
544 | # Directory has been checked previously | |
545 | ||
546 | return (undef, $path) unless -e $path; | |
547 | ||
548 | # Try again until MAX_TRIES | |
549 | ||
550 | } | |
551 | ||
552 | # Did not successfully open the tempfile/dir | |
553 | # so try again with a different set of random letters | |
554 | # No point in trying to increment unless we have only | |
555 | # 1 X say and the randomness could come up with the same | |
556 | # file MAX_TRIES in a row. | |
557 | ||
558 | # Store current attempt - in principal this implies that the | |
559 | # 3rd time around the open attempt that the first temp file | |
560 | # name could be generated again. Probably should store each | |
561 | # attempt and make sure that none are repeated | |
562 | ||
563 | my $original = $path; | |
564 | my $counter = 0; # Stop infinite loop | |
565 | my $MAX_GUESS = 50; | |
566 | ||
567 | do { | |
568 | ||
569 | # Generate new name from original template | |
570 | $path = _replace_XX($template, $options{"suffixlen"}); | |
571 | ||
572 | $counter++; | |
573 | ||
574 | } until ($path ne $original || $counter > $MAX_GUESS); | |
575 | ||
576 | # Check for out of control looping | |
577 | if ($counter > $MAX_GUESS) { | |
578 | ${$options{ErrStr}} = "Tried to get a new temp name different to the previous value $MAX_GUESS times.\nSomething wrong with template?? ($template)"; | |
579 | return (); | |
580 | } | |
581 | ||
582 | } | |
583 | ||
584 | # If we get here, we have run out of tries | |
585 | ${ $options{ErrStr} } = "Have exceeded the maximum number of attempts (" | |
586 | . MAX_TRIES . ") to open temp file/dir"; | |
587 | ||
588 | return (); | |
589 | ||
590 | } | |
591 | ||
592 | # Internal routine to return a random character from the | |
593 | # character list. Does not do an srand() since rand() | |
594 | # will do one automatically | |
595 | ||
596 | # No arguments. Return value is the random character | |
597 | ||
598 | # No longer called since _replace_XX runs a few percent faster if | |
599 | # I inline the code. This is important if we are creating thousands of | |
600 | # temporary files. | |
601 | ||
602 | sub _randchar { | |
603 | ||
604 | $CHARS[ int( rand( $#CHARS ) ) ]; | |
605 | ||
606 | } | |
607 | ||
608 | # Internal routine to replace the XXXX... with random characters | |
609 | # This has to be done by _gettemp() every time it fails to | |
610 | # open a temp file/dir | |
611 | ||
612 | # Arguments: $template (the template with XXX), | |
613 | # $ignore (number of characters at end to ignore) | |
614 | ||
615 | # Returns: modified template | |
616 | ||
617 | sub _replace_XX { | |
618 | ||
619 | croak 'Usage: _replace_XX($template, $ignore)' | |
620 | unless scalar(@_) == 2; | |
621 | ||
622 | my ($path, $ignore) = @_; | |
623 | ||
624 | # Do it as an if, since the suffix adjusts which section to replace | |
625 | # and suffixlen=0 returns nothing if used in the substr directly | |
626 | # Alternatively, could simply set $ignore to length($path)-1 | |
627 | # Don't want to always use substr when not required though. | |
628 | ||
629 | if ($ignore) { | |
630 | substr($path, 0, - $ignore) =~ s/X(?=X*\z)/$CHARS[ int( rand( $#CHARS ) ) ]/ge; | |
631 | } else { | |
632 | $path =~ s/X(?=X*\z)/$CHARS[ int( rand( $#CHARS ) ) ]/ge; | |
633 | } | |
634 | return $path; | |
635 | } | |
636 | ||
637 | # Internal routine to force a temp file to be writable after | |
638 | # it is created so that we can unlink it. Windows seems to occassionally | |
639 | # force a file to be readonly when written to certain temp locations | |
640 | sub _force_writable { | |
641 | my $file = shift; | |
642 | my $umask = umask(); | |
643 | umask(066); | |
644 | chmod 0600, $file; | |
645 | umask($umask) if defined $umask; | |
646 | } | |
647 | ||
648 | ||
649 | # internal routine to check to see if the directory is safe | |
650 | # First checks to see if the directory is not owned by the | |
651 | # current user or root. Then checks to see if anyone else | |
652 | # can write to the directory and if so, checks to see if | |
653 | # it has the sticky bit set | |
654 | ||
655 | # Will not work on systems that do not support sticky bit | |
656 | ||
657 | #Args: directory path to check | |
658 | # Optionally: reference to scalar to contain error message | |
659 | # Returns true if the path is safe and false otherwise. | |
660 | # Returns undef if can not even run stat() on the path | |
661 | ||
662 | # This routine based on version written by Tom Christiansen | |
663 | ||
664 | # Presumably, by the time we actually attempt to create the | |
665 | # file or directory in this directory, it may not be safe | |
666 | # anymore... Have to run _is_safe directly after the open. | |
667 | ||
668 | sub _is_safe { | |
669 | ||
670 | my $path = shift; | |
671 | my $err_ref = shift; | |
672 | ||
673 | # Stat path | |
674 | my @info = stat($path); | |
675 | unless (scalar(@info)) { | |
676 | $$err_ref = "stat(path) returned no values"; | |
677 | return 0; | |
678 | }; | |
679 | return 1 if $^O eq 'VMS'; # owner delete control at file level | |
680 | ||
681 | # Check to see whether owner is neither superuser (or a system uid) nor me | |
682 | # Use the real uid from the $< variable | |
683 | # UID is in [4] | |
684 | if ($info[4] > File::Temp->top_system_uid() && $info[4] != $<) { | |
685 | ||
686 | Carp::cluck(sprintf "uid=$info[4] topuid=%s \$<=$< path='$path'", | |
687 | File::Temp->top_system_uid()); | |
688 | ||
689 | $$err_ref = "Directory owned neither by root nor the current user" | |
690 | if ref($err_ref); | |
691 | return 0; | |
692 | } | |
693 | ||
694 | # check whether group or other can write file | |
695 | # use 066 to detect either reading or writing | |
696 | # use 022 to check writability | |
697 | # Do it with S_IWOTH and S_IWGRP for portability (maybe) | |
698 | # mode is in info[2] | |
699 | if (($info[2] & &Fcntl::S_IWGRP) || # Is group writable? | |
700 | ($info[2] & &Fcntl::S_IWOTH) ) { # Is world writable? | |
701 | # Must be a directory | |
702 | unless (-d $path) { | |
703 | $$err_ref = "Path ($path) is not a directory" | |
704 | if ref($err_ref); | |
705 | return 0; | |
706 | } | |
707 | # Must have sticky bit set | |
708 | unless (-k $path) { | |
709 | $$err_ref = "Sticky bit not set on $path when dir is group|world writable" | |
710 | if ref($err_ref); | |
711 | return 0; | |
712 | } | |
713 | } | |
714 | ||
715 | return 1; | |
716 | } | |
717 | ||
718 | # Internal routine to check whether a directory is safe | |
719 | # for temp files. Safer than _is_safe since it checks for | |
720 | # the possibility of chown giveaway and if that is a possibility | |
721 | # checks each directory in the path to see if it is safe (with _is_safe) | |
722 | ||
723 | # If _PC_CHOWN_RESTRICTED is not set, does the full test of each | |
724 | # directory anyway. | |
725 | ||
726 | # Takes optional second arg as scalar ref to error reason | |
727 | ||
728 | sub _is_verysafe { | |
729 | ||
730 | # Need POSIX - but only want to bother if really necessary due to overhead | |
731 | require POSIX; | |
732 | ||
733 | my $path = shift; | |
734 | print "_is_verysafe testing $path\n" if $DEBUG; | |
735 | return 1 if $^O eq 'VMS'; # owner delete control at file level | |
736 | ||
737 | my $err_ref = shift; | |
738 | ||
739 | # Should Get the value of _PC_CHOWN_RESTRICTED if it is defined | |
740 | # and If it is not there do the extensive test | |
741 | my $chown_restricted; | |
742 | $chown_restricted = &POSIX::_PC_CHOWN_RESTRICTED() | |
743 | if eval { &POSIX::_PC_CHOWN_RESTRICTED(); 1}; | |
744 | ||
745 | # If chown_resticted is set to some value we should test it | |
746 | if (defined $chown_restricted) { | |
747 | ||
748 | # Return if the current directory is safe | |
749 | return _is_safe($path,$err_ref) if POSIX::sysconf( $chown_restricted ); | |
750 | ||
751 | } | |
752 | ||
753 | # To reach this point either, the _PC_CHOWN_RESTRICTED symbol | |
754 | # was not avialable or the symbol was there but chown giveaway | |
755 | # is allowed. Either way, we now have to test the entire tree for | |
756 | # safety. | |
757 | ||
758 | # Convert path to an absolute directory if required | |
759 | unless (File::Spec->file_name_is_absolute($path)) { | |
760 | $path = File::Spec->rel2abs($path); | |
761 | } | |
762 | ||
763 | # Split directory into components - assume no file | |
764 | my ($volume, $directories, undef) = File::Spec->splitpath( $path, 1); | |
765 | ||
766 | # Slightly less efficient than having a function in File::Spec | |
767 | # to chop off the end of a directory or even a function that | |
768 | # can handle ../ in a directory tree | |
769 | # Sometimes splitdir() returns a blank at the end | |
770 | # so we will probably check the bottom directory twice in some cases | |
771 | my @dirs = File::Spec->splitdir($directories); | |
772 | ||
773 | # Concatenate one less directory each time around | |
774 | foreach my $pos (0.. $#dirs) { | |
775 | # Get a directory name | |
776 | my $dir = File::Spec->catpath($volume, | |
777 | File::Spec->catdir(@dirs[0.. $#dirs - $pos]), | |
778 | '' | |
779 | ); | |
780 | ||
781 | print "TESTING DIR $dir\n" if $DEBUG; | |
782 | ||
783 | # Check the directory | |
784 | return 0 unless _is_safe($dir,$err_ref); | |
785 | ||
786 | } | |
787 | ||
788 | return 1; | |
789 | } | |
790 | ||
791 | ||
792 | ||
793 | # internal routine to determine whether unlink works on this | |
794 | # platform for files that are currently open. | |
795 | # Returns true if we can, false otherwise. | |
796 | ||
797 | # Currently WinNT, OS/2 and VMS can not unlink an opened file | |
798 | # On VMS this is because the O_EXCL flag is used to open the | |
799 | # temporary file. Currently I do not know enough about the issues | |
800 | # on VMS to decide whether O_EXCL is a requirement. | |
801 | ||
802 | sub _can_unlink_opened_file { | |
803 | ||
804 | if ($^O eq 'MSWin32' || $^O eq 'os2' || $^O eq 'VMS' || $^O eq 'dos' || $^O eq 'MacOS') { | |
805 | return 0; | |
806 | } else { | |
807 | return 1; | |
808 | } | |
809 | ||
810 | } | |
811 | ||
812 | # internal routine to decide which security levels are allowed | |
813 | # see safe_level() for more information on this | |
814 | ||
815 | # Controls whether the supplied security level is allowed | |
816 | ||
817 | # $cando = _can_do_level( $level ) | |
818 | ||
819 | sub _can_do_level { | |
820 | ||
821 | # Get security level | |
822 | my $level = shift; | |
823 | ||
824 | # Always have to be able to do STANDARD | |
825 | return 1 if $level == STANDARD; | |
826 | ||
827 | # Currently, the systems that can do HIGH or MEDIUM are identical | |
828 | if ( $^O eq 'MSWin32' || $^O eq 'os2' || $^O eq 'cygwin' || $^O eq 'dos' || $^O eq 'MacOS' || $^O eq 'mpeix') { | |
829 | return 0; | |
830 | } else { | |
831 | return 1; | |
832 | } | |
833 | ||
834 | } | |
835 | ||
836 | # This routine sets up a deferred unlinking of a specified | |
837 | # filename and filehandle. It is used in the following cases: | |
838 | # - Called by unlink0 if an opened file can not be unlinked | |
839 | # - Called by tempfile() if files are to be removed on shutdown | |
840 | # - Called by tempdir() if directories are to be removed on shutdown | |
841 | ||
842 | # Arguments: | |
843 | # _deferred_unlink( $fh, $fname, $isdir ); | |
844 | # | |
845 | # - filehandle (so that it can be expclicitly closed if open | |
846 | # - filename (the thing we want to remove) | |
847 | # - isdir (flag to indicate that we are being given a directory) | |
848 | # [and hence no filehandle] | |
849 | ||
850 | # Status is not referred to since all the magic is done with an END block | |
851 | ||
852 | { | |
853 | # Will set up two lexical variables to contain all the files to be | |
854 | # removed. One array for files, another for directories They will | |
855 | # only exist in this block. | |
856 | ||
857 | # This means we only have to set up a single END block to remove | |
858 | # all files. | |
859 | ||
860 | # in order to prevent child processes inadvertently deleting the parent | |
861 | # temp files we use a hash to store the temp files and directories | |
862 | # created by a particular process id. | |
863 | ||
864 | # %files_to_unlink contains values that are references to an array of | |
865 | # array references containing the filehandle and filename associated with | |
866 | # the temp file. | |
867 | my (%files_to_unlink, %dirs_to_unlink); | |
868 | ||
869 | # Set up an end block to use these arrays | |
870 | END { | |
871 | cleanup(); | |
872 | } | |
873 | ||
874 | # Cleanup function. Always triggered on END but can be invoked | |
875 | # manually. | |
876 | sub cleanup { | |
877 | if (!$KEEP_ALL) { | |
878 | # Files | |
879 | my @files = (exists $files_to_unlink{$$} ? | |
880 | @{ $files_to_unlink{$$} } : () ); | |
881 | foreach my $file (@files) { | |
882 | # close the filehandle without checking its state | |
883 | # in order to make real sure that this is closed | |
884 | # if its already closed then I dont care about the answer | |
885 | # probably a better way to do this | |
886 | close($file->[0]); # file handle is [0] | |
887 | ||
888 | if (-f $file->[1]) { # file name is [1] | |
889 | _force_writable( $file->[1] ); # for windows | |
890 | unlink $file->[1] or warn "Error removing ".$file->[1]; | |
891 | } | |
892 | } | |
893 | # Dirs | |
894 | my @dirs = (exists $dirs_to_unlink{$$} ? | |
895 | @{ $dirs_to_unlink{$$} } : () ); | |
896 | foreach my $dir (@dirs) { | |
897 | if (-d $dir) { | |
898 | rmtree($dir, $DEBUG, 0); | |
899 | } | |
900 | } | |
901 | ||
902 | # clear the arrays | |
903 | @{ $files_to_unlink{$$} } = () | |
904 | if exists $files_to_unlink{$$}; | |
905 | @{ $dirs_to_unlink{$$} } = () | |
906 | if exists $dirs_to_unlink{$$}; | |
907 | } | |
908 | } | |
909 | ||
910 | ||
911 | # This is the sub called to register a file for deferred unlinking | |
912 | # This could simply store the input parameters and defer everything | |
913 | # until the END block. For now we do a bit of checking at this | |
914 | # point in order to make sure that (1) we have a file/dir to delete | |
915 | # and (2) we have been called with the correct arguments. | |
916 | sub _deferred_unlink { | |
917 | ||
918 | croak 'Usage: _deferred_unlink($fh, $fname, $isdir)' | |
919 | unless scalar(@_) == 3; | |
920 | ||
921 | my ($fh, $fname, $isdir) = @_; | |
922 | ||
923 | warn "Setting up deferred removal of $fname\n" | |
924 | if $DEBUG; | |
925 | ||
926 | # If we have a directory, check that it is a directory | |
927 | if ($isdir) { | |
928 | ||
929 | if (-d $fname) { | |
930 | ||
931 | # Directory exists so store it | |
932 | # first on VMS turn []foo into [.foo] for rmtree | |
933 | $fname = VMS::Filespec::vmspath($fname) if $^O eq 'VMS'; | |
934 | $dirs_to_unlink{$$} = [] | |
935 | unless exists $dirs_to_unlink{$$}; | |
936 | push (@{ $dirs_to_unlink{$$} }, $fname); | |
937 | ||
938 | } else { | |
939 | carp "Request to remove directory $fname could not be completed since it does not exist!\n" if $^W; | |
940 | } | |
941 | ||
942 | } else { | |
943 | ||
944 | if (-f $fname) { | |
945 | ||
946 | # file exists so store handle and name for later removal | |
947 | $files_to_unlink{$$} = [] | |
948 | unless exists $files_to_unlink{$$}; | |
949 | push(@{ $files_to_unlink{$$} }, [$fh, $fname]); | |
950 | ||
951 | } else { | |
952 | carp "Request to remove file $fname could not be completed since it is not there!\n" if $^W; | |
953 | } | |
954 | ||
955 | } | |
956 | ||
957 | } | |
958 | ||
959 | ||
960 | } | |
961 | ||
962 | =head1 OBJECT-ORIENTED INTERFACE | |
963 | ||
964 | This is the primary interface for interacting with | |
965 | C<File::Temp>. Using the OO interface a temporary file can be created | |
966 | when the object is constructed and the file can be removed when the | |
967 | object is no longer required. | |
968 | ||
969 | Note that there is no method to obtain the filehandle from the | |
970 | C<File::Temp> object. The object itself acts as a filehandle. Also, | |
971 | the object is configured such that it stringifies to the name of the | |
972 | temporary file. | |
973 | ||
974 | =over 4 | |
975 | ||
976 | =item B<new> | |
977 | ||
978 | Create a temporary file object. | |
979 | ||
980 | my $tmp = new File::Temp(); | |
981 | ||
982 | by default the object is constructed as if C<tempfile> | |
983 | was called without options, but with the additional behaviour | |
984 | that the temporary file is removed by the object destructor | |
985 | if UNLINK is set to true (the default). | |
986 | ||
987 | Supported arguments are the same as for C<tempfile>: UNLINK | |
988 | (defaulting to true), DIR and SUFFIX. Additionally, the filename | |
989 | template is specified using the TEMPLATE option. The OPEN option | |
990 | is not supported (the file is always opened). | |
991 | ||
992 | $tmp = new File::Temp( TEMPLATE => 'tempXXXXX', | |
993 | DIR => 'mydir', | |
994 | SUFFIX => '.dat'); | |
995 | ||
996 | Arguments are case insensitive. | |
997 | ||
998 | =cut | |
999 | ||
1000 | sub new { | |
1001 | my $proto = shift; | |
1002 | my $class = ref($proto) || $proto; | |
1003 | ||
1004 | # read arguments and convert keys to upper case | |
1005 | my %args = @_; | |
1006 | %args = map { uc($_), $args{$_} } keys %args; | |
1007 | ||
1008 | # see if they are unlinking (defaulting to yes) | |
1009 | my $unlink = (exists $args{UNLINK} ? $args{UNLINK} : 1 ); | |
1010 | delete $args{UNLINK}; | |
1011 | ||
1012 | # template (store it in an error so that it will | |
1013 | # disappear from the arg list of tempfile | |
1014 | my @template = ( exists $args{TEMPLATE} ? $args{TEMPLATE} : () ); | |
1015 | delete $args{TEMPLATE}; | |
1016 | ||
1017 | # Protect OPEN | |
1018 | delete $args{OPEN}; | |
1019 | ||
1020 | # Open the file and retain file handle and file name | |
1021 | my ($fh, $path) = tempfile( @template, %args ); | |
1022 | ||
1023 | print "Tmp: $fh - $path\n" if $DEBUG; | |
1024 | ||
1025 | # Store the filename in the scalar slot | |
1026 | ${*$fh} = $path; | |
1027 | ||
1028 | # Store unlink information in hash slot (plus other constructor info) | |
1029 | %{*$fh} = %args; | |
1030 | ||
1031 | # create the object | |
1032 | bless $fh, $class; | |
1033 | ||
1034 | # final method-based configuration | |
1035 | $fh->unlink_on_destroy( $unlink ); | |
1036 | ||
1037 | return $fh; | |
1038 | } | |
1039 | ||
1040 | =item B<filename> | |
1041 | ||
1042 | Return the name of the temporary file associated with this object. | |
1043 | ||
1044 | $filename = $tmp->filename; | |
1045 | ||
1046 | This method is called automatically when the object is used as | |
1047 | a string. | |
1048 | ||
1049 | =cut | |
1050 | ||
1051 | sub filename { | |
1052 | my $self = shift; | |
1053 | return ${*$self}; | |
1054 | } | |
1055 | ||
1056 | sub STRINGIFY { | |
1057 | my $self = shift; | |
1058 | return $self->filename; | |
1059 | } | |
1060 | ||
1061 | =item B<unlink_on_destroy> | |
1062 | ||
1063 | Control whether the file is unlinked when the object goes out of scope. | |
1064 | The file is removed if this value is true and $KEEP_ALL is not. | |
1065 | ||
1066 | $fh->unlink_on_destroy( 1 ); | |
1067 | ||
1068 | Default is for the file to be removed. | |
1069 | ||
1070 | =cut | |
1071 | ||
1072 | sub unlink_on_destroy { | |
1073 | my $self = shift; | |
1074 | if (@_) { | |
1075 | ${*$self}{UNLINK} = shift; | |
1076 | } | |
1077 | return ${*$self}{UNLINK}; | |
1078 | } | |
1079 | ||
1080 | =item B<DESTROY> | |
1081 | ||
1082 | When the object goes out of scope, the destructor is called. This | |
1083 | destructor will attempt to unlink the file (using C<unlink1>) | |
1084 | if the constructor was called with UNLINK set to 1 (the default state | |
1085 | if UNLINK is not specified). | |
1086 | ||
1087 | No error is given if the unlink fails. | |
1088 | ||
1089 | If the global variable $KEEP_ALL is true, the file will not be removed. | |
1090 | ||
1091 | =cut | |
1092 | ||
1093 | sub DESTROY { | |
1094 | my $self = shift; | |
1095 | if (${*$self}{UNLINK} && !$KEEP_ALL) { | |
1096 | print "# ---------> Unlinking $self\n" if $DEBUG; | |
1097 | ||
1098 | # The unlink1 may fail if the file has been closed | |
1099 | # by the caller. This leaves us with the decision | |
1100 | # of whether to refuse to remove the file or simply | |
1101 | # do an unlink without test. Seems to be silly | |
1102 | # to do this when we are trying to be careful | |
1103 | # about security | |
1104 | _force_writable( $self->filename ); # for windows | |
1105 | unlink1( $self, $self->filename ) | |
1106 | or unlink($self->filename); | |
1107 | } | |
1108 | } | |
1109 | ||
1110 | =back | |
1111 | ||
1112 | =head1 FUNCTIONS | |
1113 | ||
1114 | This section describes the recommended interface for generating | |
1115 | temporary files and directories. | |
1116 | ||
1117 | =over 4 | |
1118 | ||
1119 | =item B<tempfile> | |
1120 | ||
1121 | This is the basic function to generate temporary files. | |
1122 | The behaviour of the file can be changed using various options: | |
1123 | ||
1124 | $fh = tempfile(); | |
1125 | ($fh, $filename) = tempfile(); | |
1126 | ||
1127 | Create a temporary file in the directory specified for temporary | |
1128 | files, as specified by the tmpdir() function in L<File::Spec>. | |
1129 | ||
1130 | ($fh, $filename) = tempfile($template); | |
1131 | ||
1132 | Create a temporary file in the current directory using the supplied | |
1133 | template. Trailing `X' characters are replaced with random letters to | |
1134 | generate the filename. At least four `X' characters must be present | |
1135 | at the end of the template. | |
1136 | ||
1137 | ($fh, $filename) = tempfile($template, SUFFIX => $suffix) | |
1138 | ||
1139 | Same as previously, except that a suffix is added to the template | |
1140 | after the `X' translation. Useful for ensuring that a temporary | |
1141 | filename has a particular extension when needed by other applications. | |
1142 | But see the WARNING at the end. | |
1143 | ||
1144 | ($fh, $filename) = tempfile($template, DIR => $dir); | |
1145 | ||
1146 | Translates the template as before except that a directory name | |
1147 | is specified. | |
1148 | ||
1149 | ($fh, $filename) = tempfile($template, UNLINK => 1); | |
1150 | ||
1151 | Return the filename and filehandle as before except that the file is | |
1152 | automatically removed when the program exits (dependent on | |
1153 | $KEEP_ALL). Default is for the file to be removed if a file handle is | |
1154 | requested and to be kept if the filename is requested. In a scalar | |
1155 | context (where no filename is returned) the file is always deleted | |
1156 | either (depending on the operating system) on exit or when it is | |
1157 | closed (unless $KEEP_ALL is true when the temp file is created). | |
1158 | ||
1159 | Use the object-oriented interface if fine-grained control of when | |
1160 | a file is removed is required. | |
1161 | ||
1162 | If the template is not specified, a template is always | |
1163 | automatically generated. This temporary file is placed in tmpdir() | |
1164 | (L<File::Spec>) unless a directory is specified explicitly with the | |
1165 | DIR option. | |
1166 | ||
1167 | $fh = tempfile( $template, DIR => $dir ); | |
1168 | ||
1169 | If called in scalar context, only the filehandle is returned and the | |
1170 | file will automatically be deleted when closed on operating systems | |
1171 | that support this (see the description of tmpfile() elsewhere in this | |
1172 | document). This is the preferred mode of operation, as if you only | |
1173 | have a filehandle, you can never create a race condition by fumbling | |
1174 | with the filename. On systems that can not unlink an open file or can | |
1175 | not mark a file as temporary when it is opened (for example, Windows | |
1176 | NT uses the C<O_TEMPORARY> flag) the file is marked for deletion when | |
1177 | the program ends (equivalent to setting UNLINK to 1). The C<UNLINK> | |
1178 | flag is ignored if present. | |
1179 | ||
1180 | (undef, $filename) = tempfile($template, OPEN => 0); | |
1181 | ||
1182 | This will return the filename based on the template but | |
1183 | will not open this file. Cannot be used in conjunction with | |
1184 | UNLINK set to true. Default is to always open the file | |
1185 | to protect from possible race conditions. A warning is issued | |
1186 | if warnings are turned on. Consider using the tmpnam() | |
1187 | and mktemp() functions described elsewhere in this document | |
1188 | if opening the file is not required. | |
1189 | ||
1190 | Options can be combined as required. | |
1191 | ||
1192 | =cut | |
1193 | ||
1194 | sub tempfile { | |
1195 | ||
1196 | # Can not check for argument count since we can have any | |
1197 | # number of args | |
1198 | ||
1199 | # Default options | |
1200 | my %options = ( | |
1201 | "DIR" => undef, # Directory prefix | |
1202 | "SUFFIX" => '', # Template suffix | |
1203 | "UNLINK" => 0, # Do not unlink file on exit | |
1204 | "OPEN" => 1, # Open file | |
1205 | ); | |
1206 | ||
1207 | # Check to see whether we have an odd or even number of arguments | |
1208 | my $template = (scalar(@_) % 2 == 1 ? shift(@_) : undef); | |
1209 | ||
1210 | # Read the options and merge with defaults | |
1211 | %options = (%options, @_) if @_; | |
1212 | ||
1213 | # First decision is whether or not to open the file | |
1214 | if (! $options{"OPEN"}) { | |
1215 | ||
1216 | warn "tempfile(): temporary filename requested but not opened.\nPossibly unsafe, consider using tempfile() with OPEN set to true\n" | |
1217 | if $^W; | |
1218 | ||
1219 | } | |
1220 | ||
1221 | if ($options{"DIR"} and $^O eq 'VMS') { | |
1222 | ||
1223 | # on VMS turn []foo into [.foo] for concatenation | |
1224 | $options{"DIR"} = VMS::Filespec::vmspath($options{"DIR"}); | |
1225 | } | |
1226 | ||
1227 | # Construct the template | |
1228 | ||
1229 | # Have a choice of trying to work around the mkstemp/mktemp/tmpnam etc | |
1230 | # functions or simply constructing a template and using _gettemp() | |
1231 | # explicitly. Go for the latter | |
1232 | ||
1233 | # First generate a template if not defined and prefix the directory | |
1234 | # If no template must prefix the temp directory | |
1235 | if (defined $template) { | |
1236 | if ($options{"DIR"}) { | |
1237 | ||
1238 | $template = File::Spec->catfile($options{"DIR"}, $template); | |
1239 | ||
1240 | } | |
1241 | ||
1242 | } else { | |
1243 | ||
1244 | if ($options{"DIR"}) { | |
1245 | ||
1246 | $template = File::Spec->catfile($options{"DIR"}, TEMPXXX); | |
1247 | ||
1248 | } else { | |
1249 | ||
1250 | $template = File::Spec->catfile(File::Spec->tmpdir, TEMPXXX); | |
1251 | ||
1252 | } | |
1253 | ||
1254 | } | |
1255 | ||
1256 | # Now add a suffix | |
1257 | $template .= $options{"SUFFIX"}; | |
1258 | ||
1259 | # Determine whether we should tell _gettemp to unlink the file | |
1260 | # On unix this is irrelevant and can be worked out after the file is | |
1261 | # opened (simply by unlinking the open filehandle). On Windows or VMS | |
1262 | # we have to indicate temporary-ness when we open the file. In general | |
1263 | # we only want a true temporary file if we are returning just the | |
1264 | # filehandle - if the user wants the filename they probably do not | |
1265 | # want the file to disappear as soon as they close it (which may be | |
1266 | # important if they want a child process to use the file) | |
1267 | # For this reason, tie unlink_on_close to the return context regardless | |
1268 | # of OS. | |
1269 | my $unlink_on_close = ( wantarray ? 0 : 1); | |
1270 | ||
1271 | # Create the file | |
1272 | my ($fh, $path, $errstr); | |
1273 | croak "Error in tempfile() using $template: $errstr" | |
1274 | unless (($fh, $path) = _gettemp($template, | |
1275 | "open" => $options{'OPEN'}, | |
1276 | "mkdir"=> 0 , | |
1277 | "unlink_on_close" => $unlink_on_close, | |
1278 | "suffixlen" => length($options{'SUFFIX'}), | |
1279 | "ErrStr" => \$errstr, | |
1280 | ) ); | |
1281 | ||
1282 | # Set up an exit handler that can do whatever is right for the | |
1283 | # system. This removes files at exit when requested explicitly or when | |
1284 | # system is asked to unlink_on_close but is unable to do so because | |
1285 | # of OS limitations. | |
1286 | # The latter should be achieved by using a tied filehandle. | |
1287 | # Do not check return status since this is all done with END blocks. | |
1288 | _deferred_unlink($fh, $path, 0) if $options{"UNLINK"}; | |
1289 | ||
1290 | # Return | |
1291 | if (wantarray()) { | |
1292 | ||
1293 | if ($options{'OPEN'}) { | |
1294 | return ($fh, $path); | |
1295 | } else { | |
1296 | return (undef, $path); | |
1297 | } | |
1298 | ||
1299 | } else { | |
1300 | ||
1301 | # Unlink the file. It is up to unlink0 to decide what to do with | |
1302 | # this (whether to unlink now or to defer until later) | |
1303 | unlink0($fh, $path) or croak "Error unlinking file $path using unlink0"; | |
1304 | ||
1305 | # Return just the filehandle. | |
1306 | return $fh; | |
1307 | } | |
1308 | ||
1309 | ||
1310 | } | |
1311 | ||
1312 | =item B<tempdir> | |
1313 | ||
1314 | This is the recommended interface for creation of temporary directories. | |
1315 | The behaviour of the function depends on the arguments: | |
1316 | ||
1317 | $tempdir = tempdir(); | |
1318 | ||
1319 | Create a directory in tmpdir() (see L<File::Spec|File::Spec>). | |
1320 | ||
1321 | $tempdir = tempdir( $template ); | |
1322 | ||
1323 | Create a directory from the supplied template. This template is | |
1324 | similar to that described for tempfile(). `X' characters at the end | |
1325 | of the template are replaced with random letters to construct the | |
1326 | directory name. At least four `X' characters must be in the template. | |
1327 | ||
1328 | $tempdir = tempdir ( DIR => $dir ); | |
1329 | ||
1330 | Specifies the directory to use for the temporary directory. | |
1331 | The temporary directory name is derived from an internal template. | |
1332 | ||
1333 | $tempdir = tempdir ( $template, DIR => $dir ); | |
1334 | ||
1335 | Prepend the supplied directory name to the template. The template | |
1336 | should not include parent directory specifications itself. Any parent | |
1337 | directory specifications are removed from the template before | |
1338 | prepending the supplied directory. | |
1339 | ||
1340 | $tempdir = tempdir ( $template, TMPDIR => 1 ); | |
1341 | ||
1342 | Using the supplied template, create the temporary directory in | |
1343 | a standard location for temporary files. Equivalent to doing | |
1344 | ||
1345 | $tempdir = tempdir ( $template, DIR => File::Spec->tmpdir); | |
1346 | ||
1347 | but shorter. Parent directory specifications are stripped from the | |
1348 | template itself. The C<TMPDIR> option is ignored if C<DIR> is set | |
1349 | explicitly. Additionally, C<TMPDIR> is implied if neither a template | |
1350 | nor a directory are supplied. | |
1351 | ||
1352 | $tempdir = tempdir( $template, CLEANUP => 1); | |
1353 | ||
1354 | Create a temporary directory using the supplied template, but | |
1355 | attempt to remove it (and all files inside it) when the program | |
1356 | exits. Note that an attempt will be made to remove all files from | |
1357 | the directory even if they were not created by this module (otherwise | |
1358 | why ask to clean it up?). The directory removal is made with | |
1359 | the rmtree() function from the L<File::Path|File::Path> module. | |
1360 | Of course, if the template is not specified, the temporary directory | |
1361 | will be created in tmpdir() and will also be removed at program exit. | |
1362 | ||
1363 | =cut | |
1364 | ||
1365 | # ' | |
1366 | ||
1367 | sub tempdir { | |
1368 | ||
1369 | # Can not check for argument count since we can have any | |
1370 | # number of args | |
1371 | ||
1372 | # Default options | |
1373 | my %options = ( | |
1374 | "CLEANUP" => 0, # Remove directory on exit | |
1375 | "DIR" => '', # Root directory | |
1376 | "TMPDIR" => 0, # Use tempdir with template | |
1377 | ); | |
1378 | ||
1379 | # Check to see whether we have an odd or even number of arguments | |
1380 | my $template = (scalar(@_) % 2 == 1 ? shift(@_) : undef ); | |
1381 | ||
1382 | # Read the options and merge with defaults | |
1383 | %options = (%options, @_) if @_; | |
1384 | ||
1385 | # Modify or generate the template | |
1386 | ||
1387 | # Deal with the DIR and TMPDIR options | |
1388 | if (defined $template) { | |
1389 | ||
1390 | # Need to strip directory path if using DIR or TMPDIR | |
1391 | if ($options{'TMPDIR'} || $options{'DIR'}) { | |
1392 | ||
1393 | # Strip parent directory from the filename | |
1394 | # | |
1395 | # There is no filename at the end | |
1396 | $template = VMS::Filespec::vmspath($template) if $^O eq 'VMS'; | |
1397 | my ($volume, $directories, undef) = File::Spec->splitpath( $template, 1); | |
1398 | ||
1399 | # Last directory is then our template | |
1400 | $template = (File::Spec->splitdir($directories))[-1]; | |
1401 | ||
1402 | # Prepend the supplied directory or temp dir | |
1403 | if ($options{"DIR"}) { | |
1404 | ||
1405 | $template = File::Spec->catdir($options{"DIR"}, $template); | |
1406 | ||
1407 | } elsif ($options{TMPDIR}) { | |
1408 | ||
1409 | # Prepend tmpdir | |
1410 | $template = File::Spec->catdir(File::Spec->tmpdir, $template); | |
1411 | ||
1412 | } | |
1413 | ||
1414 | } | |
1415 | ||
1416 | } else { | |
1417 | ||
1418 | if ($options{"DIR"}) { | |
1419 | ||
1420 | $template = File::Spec->catdir($options{"DIR"}, TEMPXXX); | |
1421 | ||
1422 | } else { | |
1423 | ||
1424 | $template = File::Spec->catdir(File::Spec->tmpdir, TEMPXXX); | |
1425 | ||
1426 | } | |
1427 | ||
1428 | } | |
1429 | ||
1430 | # Create the directory | |
1431 | my $tempdir; | |
1432 | my $suffixlen = 0; | |
1433 | if ($^O eq 'VMS') { # dir names can end in delimiters | |
1434 | $template =~ m/([\.\]:>]+)$/; | |
1435 | $suffixlen = length($1); | |
1436 | } | |
1437 | if ( ($^O eq 'MacOS') && (substr($template, -1) eq ':') ) { | |
1438 | # dir name has a trailing ':' | |
1439 | ++$suffixlen; | |
1440 | } | |
1441 | ||
1442 | my $errstr; | |
1443 | croak "Error in tempdir() using $template: $errstr" | |
1444 | unless ((undef, $tempdir) = _gettemp($template, | |
1445 | "open" => 0, | |
1446 | "mkdir"=> 1 , | |
1447 | "suffixlen" => $suffixlen, | |
1448 | "ErrStr" => \$errstr, | |
1449 | ) ); | |
1450 | ||
1451 | # Install exit handler; must be dynamic to get lexical | |
1452 | if ( $options{'CLEANUP'} && -d $tempdir) { | |
1453 | _deferred_unlink(undef, $tempdir, 1); | |
1454 | } | |
1455 | ||
1456 | # Return the dir name | |
1457 | return $tempdir; | |
1458 | ||
1459 | } | |
1460 | ||
1461 | =back | |
1462 | ||
1463 | =head1 MKTEMP FUNCTIONS | |
1464 | ||
1465 | The following functions are Perl implementations of the | |
1466 | mktemp() family of temp file generation system calls. | |
1467 | ||
1468 | =over 4 | |
1469 | ||
1470 | =item B<mkstemp> | |
1471 | ||
1472 | Given a template, returns a filehandle to the temporary file and the name | |
1473 | of the file. | |
1474 | ||
1475 | ($fh, $name) = mkstemp( $template ); | |
1476 | ||
1477 | In scalar context, just the filehandle is returned. | |
1478 | ||
1479 | The template may be any filename with some number of X's appended | |
1480 | to it, for example F</tmp/temp.XXXX>. The trailing X's are replaced | |
1481 | with unique alphanumeric combinations. | |
1482 | ||
1483 | =cut | |
1484 | ||
1485 | ||
1486 | ||
1487 | sub mkstemp { | |
1488 | ||
1489 | croak "Usage: mkstemp(template)" | |
1490 | if scalar(@_) != 1; | |
1491 | ||
1492 | my $template = shift; | |
1493 | ||
1494 | my ($fh, $path, $errstr); | |
1495 | croak "Error in mkstemp using $template: $errstr" | |
1496 | unless (($fh, $path) = _gettemp($template, | |
1497 | "open" => 1, | |
1498 | "mkdir"=> 0 , | |
1499 | "suffixlen" => 0, | |
1500 | "ErrStr" => \$errstr, | |
1501 | ) ); | |
1502 | ||
1503 | if (wantarray()) { | |
1504 | return ($fh, $path); | |
1505 | } else { | |
1506 | return $fh; | |
1507 | } | |
1508 | ||
1509 | } | |
1510 | ||
1511 | ||
1512 | =item B<mkstemps> | |
1513 | ||
1514 | Similar to mkstemp(), except that an extra argument can be supplied | |
1515 | with a suffix to be appended to the template. | |
1516 | ||
1517 | ($fh, $name) = mkstemps( $template, $suffix ); | |
1518 | ||
1519 | For example a template of C<testXXXXXX> and suffix of C<.dat> | |
1520 | would generate a file similar to F<testhGji_w.dat>. | |
1521 | ||
1522 | Returns just the filehandle alone when called in scalar context. | |
1523 | ||
1524 | =cut | |
1525 | ||
1526 | sub mkstemps { | |
1527 | ||
1528 | croak "Usage: mkstemps(template, suffix)" | |
1529 | if scalar(@_) != 2; | |
1530 | ||
1531 | ||
1532 | my $template = shift; | |
1533 | my $suffix = shift; | |
1534 | ||
1535 | $template .= $suffix; | |
1536 | ||
1537 | my ($fh, $path, $errstr); | |
1538 | croak "Error in mkstemps using $template: $errstr" | |
1539 | unless (($fh, $path) = _gettemp($template, | |
1540 | "open" => 1, | |
1541 | "mkdir"=> 0 , | |
1542 | "suffixlen" => length($suffix), | |
1543 | "ErrStr" => \$errstr, | |
1544 | ) ); | |
1545 | ||
1546 | if (wantarray()) { | |
1547 | return ($fh, $path); | |
1548 | } else { | |
1549 | return $fh; | |
1550 | } | |
1551 | ||
1552 | } | |
1553 | ||
1554 | =item B<mkdtemp> | |
1555 | ||
1556 | Create a directory from a template. The template must end in | |
1557 | X's that are replaced by the routine. | |
1558 | ||
1559 | $tmpdir_name = mkdtemp($template); | |
1560 | ||
1561 | Returns the name of the temporary directory created. | |
1562 | Returns undef on failure. | |
1563 | ||
1564 | Directory must be removed by the caller. | |
1565 | ||
1566 | =cut | |
1567 | ||
1568 | #' # for emacs | |
1569 | ||
1570 | sub mkdtemp { | |
1571 | ||
1572 | croak "Usage: mkdtemp(template)" | |
1573 | if scalar(@_) != 1; | |
1574 | ||
1575 | my $template = shift; | |
1576 | my $suffixlen = 0; | |
1577 | if ($^O eq 'VMS') { # dir names can end in delimiters | |
1578 | $template =~ m/([\.\]:>]+)$/; | |
1579 | $suffixlen = length($1); | |
1580 | } | |
1581 | if ( ($^O eq 'MacOS') && (substr($template, -1) eq ':') ) { | |
1582 | # dir name has a trailing ':' | |
1583 | ++$suffixlen; | |
1584 | } | |
1585 | my ($junk, $tmpdir, $errstr); | |
1586 | croak "Error creating temp directory from template $template\: $errstr" | |
1587 | unless (($junk, $tmpdir) = _gettemp($template, | |
1588 | "open" => 0, | |
1589 | "mkdir"=> 1 , | |
1590 | "suffixlen" => $suffixlen, | |
1591 | "ErrStr" => \$errstr, | |
1592 | ) ); | |
1593 | ||
1594 | return $tmpdir; | |
1595 | ||
1596 | } | |
1597 | ||
1598 | =item B<mktemp> | |
1599 | ||
1600 | Returns a valid temporary filename but does not guarantee | |
1601 | that the file will not be opened by someone else. | |
1602 | ||
1603 | $unopened_file = mktemp($template); | |
1604 | ||
1605 | Template is the same as that required by mkstemp(). | |
1606 | ||
1607 | =cut | |
1608 | ||
1609 | sub mktemp { | |
1610 | ||
1611 | croak "Usage: mktemp(template)" | |
1612 | if scalar(@_) != 1; | |
1613 | ||
1614 | my $template = shift; | |
1615 | ||
1616 | my ($tmpname, $junk, $errstr); | |
1617 | croak "Error getting name to temp file from template $template: $errstr" | |
1618 | unless (($junk, $tmpname) = _gettemp($template, | |
1619 | "open" => 0, | |
1620 | "mkdir"=> 0 , | |
1621 | "suffixlen" => 0, | |
1622 | "ErrStr" => \$errstr, | |
1623 | ) ); | |
1624 | ||
1625 | return $tmpname; | |
1626 | } | |
1627 | ||
1628 | =back | |
1629 | ||
1630 | =head1 POSIX FUNCTIONS | |
1631 | ||
1632 | This section describes the re-implementation of the tmpnam() | |
1633 | and tmpfile() functions described in L<POSIX> | |
1634 | using the mkstemp() from this module. | |
1635 | ||
1636 | Unlike the L<POSIX|POSIX> implementations, the directory used | |
1637 | for the temporary file is not specified in a system include | |
1638 | file (C<P_tmpdir>) but simply depends on the choice of tmpdir() | |
1639 | returned by L<File::Spec|File::Spec>. On some implementations this | |
1640 | location can be set using the C<TMPDIR> environment variable, which | |
1641 | may not be secure. | |
1642 | If this is a problem, simply use mkstemp() and specify a template. | |
1643 | ||
1644 | =over 4 | |
1645 | ||
1646 | =item B<tmpnam> | |
1647 | ||
1648 | When called in scalar context, returns the full name (including path) | |
1649 | of a temporary file (uses mktemp()). The only check is that the file does | |
1650 | not already exist, but there is no guarantee that that condition will | |
1651 | continue to apply. | |
1652 | ||
1653 | $file = tmpnam(); | |
1654 | ||
1655 | When called in list context, a filehandle to the open file and | |
1656 | a filename are returned. This is achieved by calling mkstemp() | |
1657 | after constructing a suitable template. | |
1658 | ||
1659 | ($fh, $file) = tmpnam(); | |
1660 | ||
1661 | If possible, this form should be used to prevent possible | |
1662 | race conditions. | |
1663 | ||
1664 | See L<File::Spec/tmpdir> for information on the choice of temporary | |
1665 | directory for a particular operating system. | |
1666 | ||
1667 | =cut | |
1668 | ||
1669 | sub tmpnam { | |
1670 | ||
1671 | # Retrieve the temporary directory name | |
1672 | my $tmpdir = File::Spec->tmpdir; | |
1673 | ||
1674 | croak "Error temporary directory is not writable" | |
1675 | if $tmpdir eq ''; | |
1676 | ||
1677 | # Use a ten character template and append to tmpdir | |
1678 | my $template = File::Spec->catfile($tmpdir, TEMPXXX); | |
1679 | ||
1680 | if (wantarray() ) { | |
1681 | return mkstemp($template); | |
1682 | } else { | |
1683 | return mktemp($template); | |
1684 | } | |
1685 | ||
1686 | } | |
1687 | ||
1688 | =item B<tmpfile> | |
1689 | ||
1690 | Returns the filehandle of a temporary file. | |
1691 | ||
1692 | $fh = tmpfile(); | |
1693 | ||
1694 | The file is removed when the filehandle is closed or when the program | |
1695 | exits. No access to the filename is provided. | |
1696 | ||
1697 | If the temporary file can not be created undef is returned. | |
1698 | Currently this command will probably not work when the temporary | |
1699 | directory is on an NFS file system. | |
1700 | ||
1701 | =cut | |
1702 | ||
1703 | sub tmpfile { | |
1704 | ||
1705 | # Simply call tmpnam() in a list context | |
1706 | my ($fh, $file) = tmpnam(); | |
1707 | ||
1708 | # Make sure file is removed when filehandle is closed | |
1709 | # This will fail on NFS | |
1710 | unlink0($fh, $file) | |
1711 | or return undef; | |
1712 | ||
1713 | return $fh; | |
1714 | ||
1715 | } | |
1716 | ||
1717 | =back | |
1718 | ||
1719 | =head1 ADDITIONAL FUNCTIONS | |
1720 | ||
1721 | These functions are provided for backwards compatibility | |
1722 | with common tempfile generation C library functions. | |
1723 | ||
1724 | They are not exported and must be addressed using the full package | |
1725 | name. | |
1726 | ||
1727 | =over 4 | |
1728 | ||
1729 | =item B<tempnam> | |
1730 | ||
1731 | Return the name of a temporary file in the specified directory | |
1732 | using a prefix. The file is guaranteed not to exist at the time | |
1733 | the function was called, but such guarantees are good for one | |
1734 | clock tick only. Always use the proper form of C<sysopen> | |
1735 | with C<O_CREAT | O_EXCL> if you must open such a filename. | |
1736 | ||
1737 | $filename = File::Temp::tempnam( $dir, $prefix ); | |
1738 | ||
1739 | Equivalent to running mktemp() with $dir/$prefixXXXXXXXX | |
1740 | (using unix file convention as an example) | |
1741 | ||
1742 | Because this function uses mktemp(), it can suffer from race conditions. | |
1743 | ||
1744 | =cut | |
1745 | ||
1746 | sub tempnam { | |
1747 | ||
1748 | croak 'Usage tempnam($dir, $prefix)' unless scalar(@_) == 2; | |
1749 | ||
1750 | my ($dir, $prefix) = @_; | |
1751 | ||
1752 | # Add a string to the prefix | |
1753 | $prefix .= 'XXXXXXXX'; | |
1754 | ||
1755 | # Concatenate the directory to the file | |
1756 | my $template = File::Spec->catfile($dir, $prefix); | |
1757 | ||
1758 | return mktemp($template); | |
1759 | ||
1760 | } | |
1761 | ||
1762 | =back | |
1763 | ||
1764 | =head1 UTILITY FUNCTIONS | |
1765 | ||
1766 | Useful functions for dealing with the filehandle and filename. | |
1767 | ||
1768 | =over 4 | |
1769 | ||
1770 | =item B<unlink0> | |
1771 | ||
1772 | Given an open filehandle and the associated filename, make a safe | |
1773 | unlink. This is achieved by first checking that the filename and | |
1774 | filehandle initially point to the same file and that the number of | |
1775 | links to the file is 1 (all fields returned by stat() are compared). | |
1776 | Then the filename is unlinked and the filehandle checked once again to | |
1777 | verify that the number of links on that file is now 0. This is the | |
1778 | closest you can come to making sure that the filename unlinked was the | |
1779 | same as the file whose descriptor you hold. | |
1780 | ||
1781 | unlink0($fh, $path) | |
1782 | or die "Error unlinking file $path safely"; | |
1783 | ||
1784 | Returns false on error. The filehandle is not closed since on some | |
1785 | occasions this is not required. | |
1786 | ||
1787 | On some platforms, for example Windows NT, it is not possible to | |
1788 | unlink an open file (the file must be closed first). On those | |
1789 | platforms, the actual unlinking is deferred until the program ends and | |
1790 | good status is returned. A check is still performed to make sure that | |
1791 | the filehandle and filename are pointing to the same thing (but not at | |
1792 | the time the end block is executed since the deferred removal may not | |
1793 | have access to the filehandle). | |
1794 | ||
1795 | Additionally, on Windows NT not all the fields returned by stat() can | |
1796 | be compared. For example, the C<dev> and C<rdev> fields seem to be | |
1797 | different. Also, it seems that the size of the file returned by stat() | |
1798 | does not always agree, with C<stat(FH)> being more accurate than | |
1799 | C<stat(filename)>, presumably because of caching issues even when | |
1800 | using autoflush (this is usually overcome by waiting a while after | |
1801 | writing to the tempfile before attempting to C<unlink0> it). | |
1802 | ||
1803 | Finally, on NFS file systems the link count of the file handle does | |
1804 | not always go to zero immediately after unlinking. Currently, this | |
1805 | command is expected to fail on NFS disks. | |
1806 | ||
1807 | This function is disabled if the global variable $KEEP_ALL is true | |
1808 | and an unlink on open file is supported. If the unlink is to be deferred | |
1809 | to the END block, the file is still registered for removal. | |
1810 | ||
1811 | =cut | |
1812 | ||
1813 | sub unlink0 { | |
1814 | ||
1815 | croak 'Usage: unlink0(filehandle, filename)' | |
1816 | unless scalar(@_) == 2; | |
1817 | ||
1818 | # Read args | |
1819 | my ($fh, $path) = @_; | |
1820 | ||
1821 | cmpstat($fh, $path) or return 0; | |
1822 | ||
1823 | # attempt remove the file (does not work on some platforms) | |
1824 | if (_can_unlink_opened_file()) { | |
1825 | ||
1826 | # return early (Without unlink) if we have been instructed to retain files. | |
1827 | return 1 if $KEEP_ALL; | |
1828 | ||
1829 | # XXX: do *not* call this on a directory; possible race | |
1830 | # resulting in recursive removal | |
1831 | croak "unlink0: $path has become a directory!" if -d $path; | |
1832 | unlink($path) or return 0; | |
1833 | ||
1834 | # Stat the filehandle | |
1835 | my @fh = stat $fh; | |
1836 | ||
1837 | print "Link count = $fh[3] \n" if $DEBUG; | |
1838 | ||
1839 | # Make sure that the link count is zero | |
1840 | # - Cygwin provides deferred unlinking, however, | |
1841 | # on Win9x the link count remains 1 | |
1842 | # On NFS the link count may still be 1 but we cant know that | |
1843 | # we are on NFS | |
1844 | return ( $fh[3] == 0 or $^O eq 'cygwin' ? 1 : 0); | |
1845 | ||
1846 | } else { | |
1847 | _deferred_unlink($fh, $path, 0); | |
1848 | return 1; | |
1849 | } | |
1850 | ||
1851 | } | |
1852 | ||
1853 | =item B<cmpstat> | |
1854 | ||
1855 | Compare C<stat> of filehandle with C<stat> of provided filename. This | |
1856 | can be used to check that the filename and filehandle initially point | |
1857 | to the same file and that the number of links to the file is 1 (all | |
1858 | fields returned by stat() are compared). | |
1859 | ||
1860 | cmpstat($fh, $path) | |
1861 | or die "Error comparing handle with file"; | |
1862 | ||
1863 | Returns false if the stat information differs or if the link count is | |
1864 | greater than 1. | |
1865 | ||
1866 | On certain platofms, eg Windows, not all the fields returned by stat() | |
1867 | can be compared. For example, the C<dev> and C<rdev> fields seem to be | |
1868 | different in Windows. Also, it seems that the size of the file | |
1869 | returned by stat() does not always agree, with C<stat(FH)> being more | |
1870 | accurate than C<stat(filename)>, presumably because of caching issues | |
1871 | even when using autoflush (this is usually overcome by waiting a while | |
1872 | after writing to the tempfile before attempting to C<unlink0> it). | |
1873 | ||
1874 | Not exported by default. | |
1875 | ||
1876 | =cut | |
1877 | ||
1878 | sub cmpstat { | |
1879 | ||
1880 | croak 'Usage: cmpstat(filehandle, filename)' | |
1881 | unless scalar(@_) == 2; | |
1882 | ||
1883 | # Read args | |
1884 | my ($fh, $path) = @_; | |
1885 | ||
1886 | warn "Comparing stat\n" | |
1887 | if $DEBUG; | |
1888 | ||
1889 | # Stat the filehandle - which may be closed if someone has manually | |
1890 | # closed the file. Can not turn off warnings without using $^W | |
1891 | # unless we upgrade to 5.006 minimum requirement | |
1892 | my @fh; | |
1893 | { | |
1894 | local ($^W) = 0; | |
1895 | @fh = stat $fh; | |
1896 | } | |
1897 | return unless @fh; | |
1898 | ||
1899 | if ($fh[3] > 1 && $^W) { | |
1900 | carp "unlink0: fstat found too many links; SB=@fh" if $^W; | |
1901 | } | |
1902 | ||
1903 | # Stat the path | |
1904 | my @path = stat $path; | |
1905 | ||
1906 | unless (@path) { | |
1907 | carp "unlink0: $path is gone already" if $^W; | |
1908 | return; | |
1909 | } | |
1910 | ||
1911 | # this is no longer a file, but may be a directory, or worse | |
1912 | unless (-f $path) { | |
1913 | confess "panic: $path is no longer a file: SB=@fh"; | |
1914 | } | |
1915 | ||
1916 | # Do comparison of each member of the array | |
1917 | # On WinNT dev and rdev seem to be different | |
1918 | # depending on whether it is a file or a handle. | |
1919 | # Cannot simply compare all members of the stat return | |
1920 | # Select the ones we can use | |
1921 | my @okstat = (0..$#fh); # Use all by default | |
1922 | if ($^O eq 'MSWin32') { | |
1923 | @okstat = (1,2,3,4,5,7,8,9,10); | |
1924 | } elsif ($^O eq 'os2') { | |
1925 | @okstat = (0, 2..$#fh); | |
1926 | } elsif ($^O eq 'VMS') { # device and file ID are sufficient | |
1927 | @okstat = (0, 1); | |
1928 | } elsif ($^O eq 'dos') { | |
1929 | @okstat = (0,2..7,11..$#fh); | |
1930 | } elsif ($^O eq 'mpeix') { | |
1931 | @okstat = (0..4,8..10); | |
1932 | } | |
1933 | ||
1934 | # Now compare each entry explicitly by number | |
1935 | for (@okstat) { | |
1936 | print "Comparing: $_ : $fh[$_] and $path[$_]\n" if $DEBUG; | |
1937 | # Use eq rather than == since rdev, blksize, and blocks (6, 11, | |
1938 | # and 12) will be '' on platforms that do not support them. This | |
1939 | # is fine since we are only comparing integers. | |
1940 | unless ($fh[$_] eq $path[$_]) { | |
1941 | warn "Did not match $_ element of stat\n" if $DEBUG; | |
1942 | return 0; | |
1943 | } | |
1944 | } | |
1945 | ||
1946 | return 1; | |
1947 | } | |
1948 | ||
1949 | =item B<unlink1> | |
1950 | ||
1951 | Similar to C<unlink0> except after file comparison using cmpstat, the | |
1952 | filehandle is closed prior to attempting to unlink the file. This | |
1953 | allows the file to be removed without using an END block, but does | |
1954 | mean that the post-unlink comparison of the filehandle state provided | |
1955 | by C<unlink0> is not available. | |
1956 | ||
1957 | unlink1($fh, $path) | |
1958 | or die "Error closing and unlinking file"; | |
1959 | ||
1960 | Usually called from the object destructor when using the OO interface. | |
1961 | ||
1962 | Not exported by default. | |
1963 | ||
1964 | This function is disabled if the global variable $KEEP_ALL is true. | |
1965 | ||
1966 | =cut | |
1967 | ||
1968 | sub unlink1 { | |
1969 | croak 'Usage: unlink1(filehandle, filename)' | |
1970 | unless scalar(@_) == 2; | |
1971 | ||
1972 | # Read args | |
1973 | my ($fh, $path) = @_; | |
1974 | ||
1975 | cmpstat($fh, $path) or return 0; | |
1976 | ||
1977 | # Close the file | |
1978 | close( $fh ) or return 0; | |
1979 | ||
1980 | # Make sure the file is writable (for windows) | |
1981 | _force_writable( $path ); | |
1982 | ||
1983 | # return early (without unlink) if we have been instructed to retain files. | |
1984 | return 1 if $KEEP_ALL; | |
1985 | ||
1986 | # remove the file | |
1987 | return unlink($path); | |
1988 | } | |
1989 | ||
1990 | =item B<cleanup> | |
1991 | ||
1992 | Calling this function will cause any temp files or temp directories | |
1993 | that are registered for removal to be removed. This happens automatically | |
1994 | when the process exits but can be triggered manually if the caller is sure | |
1995 | that none of the temp files are required. This method can be registered as | |
1996 | an Apache callback. | |
1997 | ||
1998 | On OSes where temp files are automatically removed when the temp file | |
1999 | is closed, calling this function will have no effect other than to remove | |
2000 | temporary directories (which may include temporary files). | |
2001 | ||
2002 | File::Temp::cleanup(); | |
2003 | ||
2004 | Not exported by default. | |
2005 | ||
2006 | =back | |
2007 | ||
2008 | =head1 PACKAGE VARIABLES | |
2009 | ||
2010 | These functions control the global state of the package. | |
2011 | ||
2012 | =over 4 | |
2013 | ||
2014 | =item B<safe_level> | |
2015 | ||
2016 | Controls the lengths to which the module will go to check the safety of the | |
2017 | temporary file or directory before proceeding. | |
2018 | Options are: | |
2019 | ||
2020 | =over 8 | |
2021 | ||
2022 | =item STANDARD | |
2023 | ||
2024 | Do the basic security measures to ensure the directory exists and | |
2025 | is writable, that the umask() is fixed before opening of the file, | |
2026 | that temporary files are opened only if they do not already exist, and | |
2027 | that possible race conditions are avoided. Finally the L<unlink0|"unlink0"> | |
2028 | function is used to remove files safely. | |
2029 | ||
2030 | =item MEDIUM | |
2031 | ||
2032 | In addition to the STANDARD security, the output directory is checked | |
2033 | to make sure that it is owned either by root or the user running the | |
2034 | program. If the directory is writable by group or by other, it is then | |
2035 | checked to make sure that the sticky bit is set. | |
2036 | ||
2037 | Will not work on platforms that do not support the C<-k> test | |
2038 | for sticky bit. | |
2039 | ||
2040 | =item HIGH | |
2041 | ||
2042 | In addition to the MEDIUM security checks, also check for the | |
2043 | possibility of ``chown() giveaway'' using the L<POSIX|POSIX> | |
2044 | sysconf() function. If this is a possibility, each directory in the | |
2045 | path is checked in turn for safeness, recursively walking back to the | |
2046 | root directory. | |
2047 | ||
2048 | For platforms that do not support the L<POSIX|POSIX> | |
2049 | C<_PC_CHOWN_RESTRICTED> symbol (for example, Windows NT) it is | |
2050 | assumed that ``chown() giveaway'' is possible and the recursive test | |
2051 | is performed. | |
2052 | ||
2053 | =back | |
2054 | ||
2055 | The level can be changed as follows: | |
2056 | ||
2057 | File::Temp->safe_level( File::Temp::HIGH ); | |
2058 | ||
2059 | The level constants are not exported by the module. | |
2060 | ||
2061 | Currently, you must be running at least perl v5.6.0 in order to | |
2062 | run with MEDIUM or HIGH security. This is simply because the | |
2063 | safety tests use functions from L<Fcntl|Fcntl> that are not | |
2064 | available in older versions of perl. The problem is that the version | |
2065 | number for Fcntl is the same in perl 5.6.0 and in 5.005_03 even though | |
2066 | they are different versions. | |
2067 | ||
2068 | On systems that do not support the HIGH or MEDIUM safety levels | |
2069 | (for example Win NT or OS/2) any attempt to change the level will | |
2070 | be ignored. The decision to ignore rather than raise an exception | |
2071 | allows portable programs to be written with high security in mind | |
2072 | for the systems that can support this without those programs failing | |
2073 | on systems where the extra tests are irrelevant. | |
2074 | ||
2075 | If you really need to see whether the change has been accepted | |
2076 | simply examine the return value of C<safe_level>. | |
2077 | ||
2078 | $newlevel = File::Temp->safe_level( File::Temp::HIGH ); | |
2079 | die "Could not change to high security" | |
2080 | if $newlevel != File::Temp::HIGH; | |
2081 | ||
2082 | =cut | |
2083 | ||
2084 | { | |
2085 | # protect from using the variable itself | |
2086 | my $LEVEL = STANDARD; | |
2087 | sub safe_level { | |
2088 | my $self = shift; | |
2089 | if (@_) { | |
2090 | my $level = shift; | |
2091 | if (($level != STANDARD) && ($level != MEDIUM) && ($level != HIGH)) { | |
2092 | carp "safe_level: Specified level ($level) not STANDARD, MEDIUM or HIGH - ignoring\n" if $^W; | |
2093 | } else { | |
2094 | # Dont allow this on perl 5.005 or earlier | |
2095 | if ($] < 5.006 && $level != STANDARD) { | |
2096 | # Cant do MEDIUM or HIGH checks | |
2097 | croak "Currently requires perl 5.006 or newer to do the safe checks"; | |
2098 | } | |
2099 | # Check that we are allowed to change level | |
2100 | # Silently ignore if we can not. | |
2101 | $LEVEL = $level if _can_do_level($level); | |
2102 | } | |
2103 | } | |
2104 | return $LEVEL; | |
2105 | } | |
2106 | } | |
2107 | ||
2108 | =item TopSystemUID | |
2109 | ||
2110 | This is the highest UID on the current system that refers to a root | |
2111 | UID. This is used to make sure that the temporary directory is | |
2112 | owned by a system UID (C<root>, C<bin>, C<sys> etc) rather than | |
2113 | simply by root. | |
2114 | ||
2115 | This is required since on many unix systems C</tmp> is not owned | |
2116 | by root. | |
2117 | ||
2118 | Default is to assume that any UID less than or equal to 10 is a root | |
2119 | UID. | |
2120 | ||
2121 | File::Temp->top_system_uid(10); | |
2122 | my $topid = File::Temp->top_system_uid; | |
2123 | ||
2124 | This value can be adjusted to reduce security checking if required. | |
2125 | The value is only relevant when C<safe_level> is set to MEDIUM or higher. | |
2126 | ||
2127 | =cut | |
2128 | ||
2129 | { | |
2130 | my $TopSystemUID = 10; | |
2131 | sub top_system_uid { | |
2132 | my $self = shift; | |
2133 | if (@_) { | |
2134 | my $newuid = shift; | |
2135 | croak "top_system_uid: UIDs should be numeric" | |
2136 | unless $newuid =~ /^\d+$/s; | |
2137 | $TopSystemUID = $newuid; | |
2138 | } | |
2139 | return $TopSystemUID; | |
2140 | } | |
2141 | } | |
2142 | ||
2143 | =item B<$KEEP_ALL> | |
2144 | ||
2145 | Controls whether temporary files and directories should be retained | |
2146 | regardless of any instructions in the program to remove them | |
2147 | automatically. This is useful for debugging but should not be used in | |
2148 | production code. | |
2149 | ||
2150 | $File::Temp::KEEP_ALL = 1; | |
2151 | ||
2152 | Default is for files to be removed as requested by the caller. | |
2153 | ||
2154 | In some cases, files will only be retained if this variable is true | |
2155 | when the file is created. This means that you can not create a temporary | |
2156 | file, set this variable and expect the temp file to still be around | |
2157 | when the program exits. | |
2158 | ||
2159 | =item B<$DEBUG> | |
2160 | ||
2161 | Controls whether debugging messages should be enabled. | |
2162 | ||
2163 | $File::Temp::DEBUG = 1; | |
2164 | ||
2165 | Default is for debugging mode to be disabled. | |
2166 | ||
2167 | =back | |
2168 | ||
2169 | =head1 WARNING | |
2170 | ||
2171 | For maximum security, endeavour always to avoid ever looking at, | |
2172 | touching, or even imputing the existence of the filename. You do not | |
2173 | know that that filename is connected to the same file as the handle | |
2174 | you have, and attempts to check this can only trigger more race | |
2175 | conditions. It's far more secure to use the filehandle alone and | |
2176 | dispense with the filename altogether. | |
2177 | ||
2178 | If you need to pass the handle to something that expects a filename | |
2179 | then, on a unix system, use C<"/dev/fd/" . fileno($fh)> for arbitrary | |
2180 | programs, or more generally C<< "+<=&" . fileno($fh) >> for Perl | |
2181 | programs. You will have to clear the close-on-exec bit on that file | |
2182 | descriptor before passing it to another process. | |
2183 | ||
2184 | use Fcntl qw/F_SETFD F_GETFD/; | |
2185 | fcntl($tmpfh, F_SETFD, 0) | |
2186 | or die "Can't clear close-on-exec flag on temp fh: $!\n"; | |
2187 | ||
2188 | =head2 Temporary files and NFS | |
2189 | ||
2190 | Some problems are associated with using temporary files that reside | |
2191 | on NFS file systems and it is recommended that a local filesystem | |
2192 | is used whenever possible. Some of the security tests will most probably | |
2193 | fail when the temp file is not local. Additionally, be aware that | |
2194 | the performance of I/O operations over NFS will not be as good as for | |
2195 | a local disk. | |
2196 | ||
2197 | =head2 Forking | |
2198 | ||
2199 | In some cases files created by File::Temp are removed from within an | |
2200 | END block. Since END blocks are triggered when a child process exits | |
2201 | (unless C<POSIX::_exit()> is used by the child) File::Temp takes care | |
2202 | to only remove those temp files created by a particular process ID. This | |
2203 | means that a child will not attempt to remove temp files created by the | |
2204 | parent process. | |
2205 | ||
2206 | =head2 BINMODE | |
2207 | ||
2208 | The file returned by File::Temp will have been opened in binary mode | |
2209 | if such a mode is available. If that is not correct, use the binmode() | |
2210 | function to change the mode of the filehandle. | |
2211 | ||
2212 | =head1 HISTORY | |
2213 | ||
2214 | Originally began life in May 1999 as an XS interface to the system | |
2215 | mkstemp() function. In March 2000, the OpenBSD mkstemp() code was | |
2216 | translated to Perl for total control of the code's | |
2217 | security checking, to ensure the presence of the function regardless of | |
2218 | operating system and to help with portability. The module was shipped | |
2219 | as a standard part of perl from v5.6.1. | |
2220 | ||
2221 | =head1 SEE ALSO | |
2222 | ||
2223 | L<POSIX/tmpnam>, L<POSIX/tmpfile>, L<File::Spec>, L<File::Path> | |
2224 | ||
2225 | See L<IO::File> and L<File::MkTemp>, L<Apachae::TempFile> for | |
2226 | different implementations of temporary file handling. | |
2227 | ||
2228 | =head1 AUTHOR | |
2229 | ||
2230 | Tim Jenness E<lt>tjenness@cpan.orgE<gt> | |
2231 | ||
2232 | Copyright (C) 1999-2005 Tim Jenness and the UK Particle Physics and | |
2233 | Astronomy Research Council. All Rights Reserved. This program is free | |
2234 | software; you can redistribute it and/or modify it under the same | |
2235 | terms as Perl itself. | |
2236 | ||
2237 | Original Perl implementation loosely based on the OpenBSD C code for | |
2238 | mkstemp(). Thanks to Tom Christiansen for suggesting that this module | |
2239 | should be written and providing ideas for code improvements and | |
2240 | security enhancements. | |
2241 | ||
2242 | =cut | |
2243 | ||
2244 | 1; |