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262eb13a |
1 | package File::Temp; |
2 | |
3 | =head1 NAME |
4 | |
5 | File::Temp - return name and handle of a temporary file safely |
6 | |
e77f578c |
7 | =begin __INTERNALS |
8 | |
9 | =head1 PORTABILITY |
10 | |
11 | This module is designed to be portable across operating systems |
12 | and it currently supports Unix, VMS, DOS, OS/2 and Windows. When |
13 | porting to a new OS there are generally three main issues |
14 | that have to be solved: |
15 | |
16 | =over 4 |
17 | |
18 | =item * |
19 | |
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20 | Can the OS unlink an open file? If it can not then the |
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21 | C<_can_unlink_opened_file> method should be modified. |
22 | |
23 | =item * |
24 | |
25 | Are the return values from C<stat> reliable? By default all the |
26 | return values from C<stat> are compared when unlinking a temporary |
27 | file using the filename and the handle. Operating systems other than |
28 | unix do not always have valid entries in all fields. If C<unlink0> fails |
29 | then the C<stat> comparison should be modified accordingly. |
30 | |
31 | =item * |
32 | |
33 | Security. Systems that can not support a test for the sticky bit |
34 | on a directory can not use the MEDIUM and HIGH security tests. |
35 | The C<_can_do_level> method should be modified accordingly. |
36 | |
37 | =back |
38 | |
39 | =end __INTERNALS |
40 | |
262eb13a |
41 | =head1 SYNOPSIS |
42 | |
43 | use File::Temp qw/ tempfile tempdir /; |
44 | |
45 | $dir = tempdir( CLEANUP => 1 ); |
46 | ($fh, $filename) = tempfile( DIR => $dir ); |
47 | |
48 | ($fh, $filename) = tempfile( $template, DIR => $dir); |
49 | ($fh, $filename) = tempfile( $template, SUFFIX => '.dat'); |
50 | |
51 | $fh = tempfile(); |
52 | |
53 | MkTemp family: |
54 | |
55 | use File::Temp qw/ :mktemp /; |
56 | |
57 | ($fh, $file) = mkstemp( "tmpfileXXXXX" ); |
58 | ($fh, $file) = mkstemps( "tmpfileXXXXXX", $suffix); |
59 | |
60 | $tmpdir = mkdtemp( $template ); |
61 | |
62 | $unopened_file = mktemp( $template ); |
63 | |
64 | POSIX functions: |
65 | |
66 | use File::Temp qw/ :POSIX /; |
67 | |
68 | $file = tmpnam(); |
69 | $fh = tmpfile(); |
70 | |
71 | ($fh, $file) = tmpnam(); |
72 | ($fh, $file) = tmpfile(); |
73 | |
74 | |
75 | Compatibility functions: |
76 | |
77 | $unopened_file = File::Temp::tempnam( $dir, $pfx ); |
78 | |
79 | =begin later |
80 | |
81 | Objects (NOT YET IMPLEMENTED): |
82 | |
83 | require File::Temp; |
84 | |
85 | $fh = new File::Temp($template); |
86 | $fname = $fh->filename; |
87 | |
88 | =end later |
89 | |
90 | =head1 DESCRIPTION |
91 | |
92 | C<File::Temp> can be used to create and open temporary files in a safe way. |
93 | The tempfile() function can be used to return the name and the open |
94 | filehandle of a temporary file. The tempdir() function can |
95 | be used to create a temporary directory. |
96 | |
97 | The security aspect of temporary file creation is emphasized such that |
781948c1 |
98 | a filehandle and filename are returned together. This helps guarantee |
99 | that a race condition can not occur where the temporary file is |
100 | created by another process between checking for the existence of the |
101 | file and its opening. Additional security levels are provided to |
102 | check, for example, that the sticky bit is set on world writable |
103 | directories. See L<"safe_level"> for more information. |
262eb13a |
104 | |
105 | For compatibility with popular C library functions, Perl implementations of |
106 | the mkstemp() family of functions are provided. These are, mkstemp(), |
107 | mkstemps(), mkdtemp() and mktemp(). |
108 | |
109 | Additionally, implementations of the standard L<POSIX|POSIX> |
110 | tmpnam() and tmpfile() functions are provided if required. |
111 | |
112 | Implementations of mktemp(), tmpnam(), and tempnam() are provided, |
113 | but should be used with caution since they return only a filename |
114 | that was valid when function was called, so cannot guarantee |
115 | that the file will not exist by the time the caller opens the filename. |
116 | |
117 | =cut |
118 | |
119 | # 5.6.0 gives us S_IWOTH, S_IWGRP, our and auto-vivifying filehandls |
120 | # People would like a version on 5.005 so give them what they want :-) |
121 | use 5.005; |
122 | use strict; |
123 | use Carp; |
124 | use File::Spec 0.8; |
125 | use File::Path qw/ rmtree /; |
126 | use Fcntl 1.03; |
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127 | use Errno; |
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128 | require VMS::Stdio if $^O eq 'VMS'; |
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129 | |
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130 | # Need the Symbol package if we are running older perl |
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131 | require Symbol if $] < 5.006; |
132 | |
133 | |
262eb13a |
134 | # use 'our' on v5.6.0 |
135 | use vars qw($VERSION @EXPORT_OK %EXPORT_TAGS $DEBUG); |
136 | |
137 | $DEBUG = 0; |
138 | |
139 | # We are exporting functions |
140 | |
262eb13a |
141 | use base qw/Exporter/; |
142 | |
143 | # Export list - to allow fine tuning of export table |
144 | |
145 | @EXPORT_OK = qw{ |
146 | tempfile |
147 | tempdir |
148 | tmpnam |
149 | tmpfile |
150 | mktemp |
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151 | mkstemp |
262eb13a |
152 | mkstemps |
153 | mkdtemp |
154 | unlink0 |
155 | }; |
156 | |
157 | # Groups of functions for export |
158 | |
159 | %EXPORT_TAGS = ( |
160 | 'POSIX' => [qw/ tmpnam tmpfile /], |
161 | 'mktemp' => [qw/ mktemp mkstemp mkstemps mkdtemp/], |
162 | ); |
163 | |
164 | # add contents of these tags to @EXPORT |
165 | Exporter::export_tags('POSIX','mktemp'); |
166 | |
167 | # Version number |
168 | |
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169 | $VERSION = '0.12'; |
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170 | |
171 | # This is a list of characters that can be used in random filenames |
172 | |
173 | 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 |
174 | 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 |
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175 | 0 1 2 3 4 5 6 7 8 9 _ |
262eb13a |
176 | /); |
177 | |
178 | # Maximum number of tries to make a temp file before failing |
179 | |
180 | use constant MAX_TRIES => 10; |
181 | |
182 | # Minimum number of X characters that should be in a template |
183 | use constant MINX => 4; |
184 | |
185 | # Default template when no template supplied |
186 | |
187 | use constant TEMPXXX => 'X' x 10; |
188 | |
189 | # Constants for the security level |
190 | |
191 | use constant STANDARD => 0; |
192 | use constant MEDIUM => 1; |
193 | use constant HIGH => 2; |
194 | |
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195 | # OPENFLAGS. If we defined the flag to use with Sysopen here this gives |
196 | # us an optimisation when many temporary files are requested |
197 | |
198 | my $OPENFLAGS = O_CREAT | O_EXCL | O_RDWR; |
199 | |
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200 | for my $oflag (qw/ FOLLOW BINARY LARGEFILE EXLOCK NOINHERIT /) { |
1c19c868 |
201 | my ($bit, $func) = (0, "Fcntl::O_" . $oflag); |
202 | no strict 'refs'; |
28d6a1e0 |
203 | $OPENFLAGS |= $bit if eval { |
204 | # Make sure that redefined die handlers do not cause problems |
205 | # eg CGI::Carp |
206 | local $SIG{__DIE__} = sub {}; |
207 | local $SIG{__WARN__} = sub {}; |
208 | $bit = &$func(); |
209 | 1; |
210 | }; |
1c19c868 |
211 | } |
212 | |
51fc852f |
213 | # On some systems the O_TEMPORARY flag can be used to tell the OS |
214 | # to automatically remove the file when it is closed. This is fine |
215 | # in most cases but not if tempfile is called with UNLINK=>0 and |
216 | # the filename is requested -- in the case where the filename is to |
217 | # be passed to another routine. This happens on windows. We overcome |
218 | # this by using a second open flags variable |
219 | |
220 | my $OPENTEMPFLAGS = $OPENFLAGS; |
221 | for my $oflag (qw/ TEMPORARY /) { |
222 | my ($bit, $func) = (0, "Fcntl::O_" . $oflag); |
223 | no strict 'refs'; |
28d6a1e0 |
224 | $OPENTEMPFLAGS |= $bit if eval { |
225 | # Make sure that redefined die handlers do not cause problems |
226 | # eg CGI::Carp |
227 | local $SIG{__DIE__} = sub {}; |
228 | local $SIG{__WARN__} = sub {}; |
229 | $bit = &$func(); |
230 | 1; |
231 | }; |
51fc852f |
232 | } |
1c19c868 |
233 | |
262eb13a |
234 | # INTERNAL ROUTINES - not to be used outside of package |
235 | |
236 | # Generic routine for getting a temporary filename |
237 | # modelled on OpenBSD _gettemp() in mktemp.c |
238 | |
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239 | # The template must contain X's that are to be replaced |
262eb13a |
240 | # with the random values |
241 | |
242 | # Arguments: |
243 | |
244 | # TEMPLATE - string containing the XXXXX's that is converted |
245 | # to a random filename and opened if required |
246 | |
247 | # Optionally, a hash can also be supplied containing specific options |
248 | # "open" => if true open the temp file, else just return the name |
249 | # default is 0 |
250 | # "mkdir"=> if true, we are creating a temp directory rather than tempfile |
251 | # default is 0 |
252 | # "suffixlen" => number of characters at end of PATH to be ignored. |
253 | # default is 0. |
51fc852f |
254 | # "unlink_on_close" => indicates that, if possible, the OS should remove |
255 | # the file as soon as it is closed. Usually indicates |
256 | # use of the O_TEMPORARY flag to sysopen. |
257 | # Usually irrelevant on unix |
258 | |
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259 | # Optionally a reference to a scalar can be passed into the function |
260 | # On error this will be used to store the reason for the error |
261 | # "ErrStr" => \$errstr |
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262 | |
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263 | # "open" and "mkdir" can not both be true |
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264 | # "unlink_on_close" is not used when "mkdir" is true. |
262eb13a |
265 | |
266 | # The default options are equivalent to mktemp(). |
267 | |
268 | # Returns: |
269 | # filehandle - open file handle (if called with doopen=1, else undef) |
270 | # temp name - name of the temp file or directory |
271 | |
272 | # For example: |
273 | # ($fh, $name) = _gettemp($template, "open" => 1); |
274 | |
275 | # for the current version, failures are associated with |
28d6a1e0 |
276 | # stored in an error string and returned to give the reason whilst debugging |
277 | # This routine is not called by any external function |
262eb13a |
278 | sub _gettemp { |
279 | |
280 | croak 'Usage: ($fh, $name) = _gettemp($template, OPTIONS);' |
281 | unless scalar(@_) >= 1; |
282 | |
28d6a1e0 |
283 | # the internal error string - expect it to be overridden |
284 | # Need this in case the caller decides not to supply us a value |
285 | # need an anonymous scalar |
286 | my $tempErrStr; |
0e939f40 |
287 | |
262eb13a |
288 | # Default options |
289 | my %options = ( |
290 | "open" => 0, |
291 | "mkdir" => 0, |
292 | "suffixlen" => 0, |
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293 | "unlink_on_close" => 0, |
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294 | "ErrStr" => \$tempErrStr, |
262eb13a |
295 | ); |
296 | |
297 | # Read the template |
298 | my $template = shift; |
299 | if (ref($template)) { |
28d6a1e0 |
300 | # Use a warning here since we have not yet merged ErrStr |
262eb13a |
301 | carp "File::Temp::_gettemp: template must not be a reference"; |
302 | return (); |
303 | } |
304 | |
305 | # Check that the number of entries on stack are even |
306 | if (scalar(@_) % 2 != 0) { |
28d6a1e0 |
307 | # Use a warning here since we have not yet merged ErrStr |
262eb13a |
308 | carp "File::Temp::_gettemp: Must have even number of options"; |
309 | return (); |
310 | } |
311 | |
312 | # Read the options and merge with defaults |
313 | %options = (%options, @_) if @_; |
669b450a |
314 | |
28d6a1e0 |
315 | # Make sure the error string is set to undef |
316 | ${$options{ErrStr}} = undef; |
0e939f40 |
317 | |
262eb13a |
318 | # Can not open the file and make a directory in a single call |
319 | if ($options{"open"} && $options{"mkdir"}) { |
28d6a1e0 |
320 | ${$options{ErrStr}} = "doopen and domkdir can not both be true\n"; |
262eb13a |
321 | return (); |
322 | } |
323 | |
324 | # Find the start of the end of the Xs (position of last X) |
325 | # Substr starts from 0 |
326 | my $start = length($template) - 1 - $options{"suffixlen"}; |
327 | |
328 | # Check that we have at least MINX x X (eg 'XXXX") at the end of the string |
329 | # (taking suffixlen into account). Any fewer is insecure. |
330 | |
331 | # Do it using substr - no reason to use a pattern match since |
332 | # we know where we are looking and what we are looking for |
333 | |
334 | if (substr($template, $start - MINX + 1, MINX) ne 'X' x MINX) { |
28d6a1e0 |
335 | ${$options{ErrStr}} = "The template must contain at least ". |
336 | MINX . " 'X' characters\n"; |
262eb13a |
337 | return (); |
338 | } |
339 | |
340 | # Replace all the X at the end of the substring with a |
341 | # random character or just all the XX at the end of a full string. |
342 | # Do it as an if, since the suffix adjusts which section to replace |
343 | # and suffixlen=0 returns nothing if used in the substr directly |
344 | # and generate a full path from the template |
345 | |
346 | my $path = _replace_XX($template, $options{"suffixlen"}); |
347 | |
348 | |
349 | # Split the path into constituent parts - eventually we need to check |
350 | # whether the directory exists |
351 | # We need to know whether we are making a temp directory |
352 | # or a tempfile |
353 | |
354 | my ($volume, $directories, $file); |
355 | my $parent; # parent directory |
356 | if ($options{"mkdir"}) { |
357 | # There is no filename at the end |
358 | ($volume, $directories, $file) = File::Spec->splitpath( $path, 1); |
359 | |
360 | # The parent is then $directories without the last directory |
361 | # Split the directory and put it back together again |
362 | my @dirs = File::Spec->splitdir($directories); |
363 | |
364 | # If @dirs only has one entry that means we are in the current |
365 | # directory |
366 | if ($#dirs == 0) { |
367 | $parent = File::Spec->curdir; |
368 | } else { |
369 | |
669b450a |
370 | if ($^O eq 'VMS') { # need volume to avoid relative dir spec |
371 | $parent = File::Spec->catdir($volume, @dirs[0..$#dirs-1]); |
e4dfc136 |
372 | $parent = 'sys$disk:[]' if $parent eq ''; |
669b450a |
373 | } else { |
374 | |
375 | # Put it back together without the last one |
376 | $parent = File::Spec->catdir(@dirs[0..$#dirs-1]); |
262eb13a |
377 | |
669b450a |
378 | # ...and attach the volume (no filename) |
379 | $parent = File::Spec->catpath($volume, $parent, ''); |
380 | } |
262eb13a |
381 | |
382 | } |
383 | |
384 | } else { |
385 | |
386 | # Get rid of the last filename (use File::Basename for this?) |
387 | ($volume, $directories, $file) = File::Spec->splitpath( $path ); |
388 | |
389 | # Join up without the file part |
390 | $parent = File::Spec->catpath($volume,$directories,''); |
391 | |
392 | # If $parent is empty replace with curdir |
393 | $parent = File::Spec->curdir |
394 | unless $directories ne ''; |
395 | |
396 | } |
397 | |
398 | # Check that the parent directories exist |
399 | # Do this even for the case where we are simply returning a name |
400 | # not a file -- no point returning a name that includes a directory |
401 | # that does not exist or is not writable |
402 | |
28d6a1e0 |
403 | unless (-d $parent) { |
404 | ${$options{ErrStr}} = "Parent directory ($parent) is not a directory"; |
405 | return (); |
406 | } |
407 | unless (-w _) { |
408 | ${$options{ErrStr}} = "Parent directory ($parent) is not writable\n"; |
262eb13a |
409 | return (); |
410 | } |
411 | |
0e939f40 |
412 | |
262eb13a |
413 | # Check the stickiness of the directory and chown giveaway if required |
414 | # If the directory is world writable the sticky bit |
415 | # must be set |
416 | |
417 | if (File::Temp->safe_level == MEDIUM) { |
28d6a1e0 |
418 | my $safeerr; |
419 | unless (_is_safe($parent,\$safeerr)) { |
420 | ${$options{ErrStr}} = "Parent directory ($parent) is not safe ($safeerr)"; |
262eb13a |
421 | return (); |
422 | } |
423 | } elsif (File::Temp->safe_level == HIGH) { |
28d6a1e0 |
424 | my $safeerr; |
425 | unless (_is_verysafe($parent, \$safeerr)) { |
426 | ${$options{ErrStr}} = "Parent directory ($parent) is not safe ($safeerr)"; |
262eb13a |
427 | return (); |
428 | } |
429 | } |
430 | |
431 | |
262eb13a |
432 | # Now try MAX_TRIES time to open the file |
433 | for (my $i = 0; $i < MAX_TRIES; $i++) { |
434 | |
435 | # Try to open the file if requested |
436 | if ($options{"open"}) { |
437 | my $fh; |
438 | |
439 | # If we are running before perl5.6.0 we can not auto-vivify |
440 | if ($] < 5.006) { |
262eb13a |
441 | $fh = &Symbol::gensym; |
442 | } |
443 | |
444 | # Try to make sure this will be marked close-on-exec |
445 | # XXX: Win32 doesn't respect this, nor the proper fcntl, |
446 | # but may have O_NOINHERIT. This may or may not be in Fcntl. |
28d6a1e0 |
447 | local $^F = 2; |
262eb13a |
448 | |
449 | # Store callers umask |
450 | my $umask = umask(); |
451 | |
452 | # Set a known umask |
453 | umask(066); |
454 | |
455 | # Attempt to open the file |
51fc852f |
456 | my $open_success = undef; |
f826e675 |
457 | if ( $^O eq 'VMS' and $options{"unlink_on_close"} ) { |
458 | # make it auto delete on close by setting FAB$V_DLT bit |
51fc852f |
459 | $fh = VMS::Stdio::vmssysopen($path, $OPENFLAGS, 0600, 'fop=dlt'); |
460 | $open_success = $fh; |
461 | } else { |
462 | my $flags = ( $options{"unlink_on_close"} ? |
463 | $OPENTEMPFLAGS : |
464 | $OPENFLAGS ); |
465 | $open_success = sysopen($fh, $path, $flags, 0600); |
466 | } |
467 | if ( $open_success ) { |
262eb13a |
468 | |
469 | # Reset umask |
470 | umask($umask); |
471 | |
472 | # Opened successfully - return file handle and name |
473 | return ($fh, $path); |
474 | |
475 | } else { |
476 | # Reset umask |
477 | umask($umask); |
478 | |
479 | # Error opening file - abort with error |
480 | # if the reason was anything but EEXIST |
11d7f64f |
481 | unless ($!{EEXIST}) { |
28d6a1e0 |
482 | ${$options{ErrStr}} = "Could not create temp file $path: $!"; |
262eb13a |
483 | return (); |
484 | } |
485 | |
486 | # Loop round for another try |
487 | |
488 | } |
489 | } elsif ($options{"mkdir"}) { |
490 | |
491 | # Store callers umask |
492 | my $umask = umask(); |
493 | |
494 | # Set a known umask |
495 | umask(066); |
496 | |
497 | # Open the temp directory |
498 | if (mkdir( $path, 0700)) { |
499 | # created okay |
500 | # Reset umask |
501 | umask($umask); |
502 | |
503 | return undef, $path; |
504 | } else { |
505 | |
506 | # Reset umask |
507 | umask($umask); |
508 | |
509 | # Abort with error if the reason for failure was anything |
510 | # except EEXIST |
11d7f64f |
511 | unless ($!{EEXIST}) { |
28d6a1e0 |
512 | ${$options{ErrStr}} = "Could not create directory $path: $!"; |
262eb13a |
513 | return (); |
514 | } |
515 | |
516 | # Loop round for another try |
517 | |
518 | } |
519 | |
520 | } else { |
521 | |
522 | # Return true if the file can not be found |
523 | # Directory has been checked previously |
524 | |
525 | return (undef, $path) unless -e $path; |
526 | |
669b450a |
527 | # Try again until MAX_TRIES |
262eb13a |
528 | |
529 | } |
669b450a |
530 | |
262eb13a |
531 | # Did not successfully open the tempfile/dir |
532 | # so try again with a different set of random letters |
533 | # No point in trying to increment unless we have only |
534 | # 1 X say and the randomness could come up with the same |
535 | # file MAX_TRIES in a row. |
536 | |
537 | # Store current attempt - in principal this implies that the |
538 | # 3rd time around the open attempt that the first temp file |
539 | # name could be generated again. Probably should store each |
540 | # attempt and make sure that none are repeated |
541 | |
542 | my $original = $path; |
543 | my $counter = 0; # Stop infinite loop |
544 | my $MAX_GUESS = 50; |
545 | |
546 | do { |
547 | |
548 | # Generate new name from original template |
549 | $path = _replace_XX($template, $options{"suffixlen"}); |
550 | |
551 | $counter++; |
552 | |
553 | } until ($path ne $original || $counter > $MAX_GUESS); |
554 | |
555 | # Check for out of control looping |
556 | if ($counter > $MAX_GUESS) { |
28d6a1e0 |
557 | ${$options{ErrStr}} = "Tried to get a new temp name different to the previous value $MAX_GUESS times.\nSomething wrong with template?? ($template)"; |
262eb13a |
558 | return (); |
559 | } |
560 | |
561 | } |
562 | |
563 | # If we get here, we have run out of tries |
28d6a1e0 |
564 | ${ $options{ErrStr} } = "Have exceeded the maximum number of attempts (" |
565 | . MAX_TRIES . ") to open temp file/dir"; |
262eb13a |
566 | |
567 | return (); |
568 | |
569 | } |
570 | |
571 | # Internal routine to return a random character from the |
572 | # character list. Does not do an srand() since rand() |
573 | # will do one automatically |
574 | |
575 | # No arguments. Return value is the random character |
576 | |
1c19c868 |
577 | # No longer called since _replace_XX runs a few percent faster if |
578 | # I inline the code. This is important if we are creating thousands of |
579 | # temporary files. |
580 | |
262eb13a |
581 | sub _randchar { |
582 | |
583 | $CHARS[ int( rand( $#CHARS ) ) ]; |
584 | |
585 | } |
586 | |
587 | # Internal routine to replace the XXXX... with random characters |
588 | # This has to be done by _gettemp() every time it fails to |
589 | # open a temp file/dir |
590 | |
591 | # Arguments: $template (the template with XXX), |
592 | # $ignore (number of characters at end to ignore) |
593 | |
594 | # Returns: modified template |
595 | |
596 | sub _replace_XX { |
597 | |
598 | croak 'Usage: _replace_XX($template, $ignore)' |
599 | unless scalar(@_) == 2; |
600 | |
601 | my ($path, $ignore) = @_; |
602 | |
603 | # Do it as an if, since the suffix adjusts which section to replace |
604 | # and suffixlen=0 returns nothing if used in the substr directly |
605 | # Alternatively, could simply set $ignore to length($path)-1 |
606 | # Don't want to always use substr when not required though. |
607 | |
608 | if ($ignore) { |
1c19c868 |
609 | substr($path, 0, - $ignore) =~ s/X(?=X*\z)/$CHARS[ int( rand( $#CHARS ) ) ]/ge; |
262eb13a |
610 | } else { |
1c19c868 |
611 | $path =~ s/X(?=X*\z)/$CHARS[ int( rand( $#CHARS ) ) ]/ge; |
262eb13a |
612 | } |
613 | |
614 | return $path; |
615 | } |
616 | |
617 | # internal routine to check to see if the directory is safe |
669b450a |
618 | # First checks to see if the directory is not owned by the |
262eb13a |
619 | # current user or root. Then checks to see if anyone else |
669b450a |
620 | # can write to the directory and if so, checks to see if |
262eb13a |
621 | # it has the sticky bit set |
622 | |
623 | # Will not work on systems that do not support sticky bit |
624 | |
625 | #Args: directory path to check |
28d6a1e0 |
626 | # Optionally: reference to scalar to contain error message |
262eb13a |
627 | # Returns true if the path is safe and false otherwise. |
628 | # Returns undef if can not even run stat() on the path |
629 | |
630 | # This routine based on version written by Tom Christiansen |
631 | |
632 | # Presumably, by the time we actually attempt to create the |
633 | # file or directory in this directory, it may not be safe |
634 | # anymore... Have to run _is_safe directly after the open. |
635 | |
636 | sub _is_safe { |
637 | |
638 | my $path = shift; |
28d6a1e0 |
639 | my $err_ref = shift; |
262eb13a |
640 | |
641 | # Stat path |
642 | my @info = stat($path); |
28d6a1e0 |
643 | unless (scalar(@info)) { |
644 | $$err_ref = "stat(path) returned no values"; |
645 | return 0; |
646 | }; |
669b450a |
647 | return 1 if $^O eq 'VMS'; # owner delete control at file level |
262eb13a |
648 | |
649 | # Check to see whether owner is neither superuser (or a system uid) nor me |
650 | # Use the real uid from the $< variable |
651 | # UID is in [4] |
73f754d1 |
652 | if ($info[4] > File::Temp->top_system_uid() && $info[4] != $<) { |
653 | |
654 | Carp::cluck(sprintf "uid=$info[4] topuid=%s \$<=$< path='$path'", |
655 | File::Temp->top_system_uid()); |
656 | |
28d6a1e0 |
657 | $$err_ref = "Directory owned neither by root nor the current user" |
658 | if ref($err_ref); |
262eb13a |
659 | return 0; |
660 | } |
661 | |
662 | # check whether group or other can write file |
663 | # use 066 to detect either reading or writing |
664 | # use 022 to check writability |
665 | # Do it with S_IWOTH and S_IWGRP for portability (maybe) |
666 | # mode is in info[2] |
667 | if (($info[2] & &Fcntl::S_IWGRP) || # Is group writable? |
668 | ($info[2] & &Fcntl::S_IWOTH) ) { # Is world writable? |
28d6a1e0 |
669 | # Must be a directory |
670 | unless (-d _) { |
671 | $$err_ref = "Path ($path) is not a directory" |
672 | if ref($err_ref); |
673 | return 0; |
674 | } |
675 | # Must have sticky bit set |
676 | unless (-k _) { |
677 | $$err_ref = "Sticky bit not set on $path when dir is group|world writable" |
678 | if ref($err_ref); |
679 | return 0; |
680 | } |
262eb13a |
681 | } |
682 | |
683 | return 1; |
684 | } |
685 | |
686 | # Internal routine to check whether a directory is safe |
687 | # for temp files. Safer than _is_safe since it checks for |
688 | # the possibility of chown giveaway and if that is a possibility |
689 | # checks each directory in the path to see if it is safe (with _is_safe) |
690 | |
691 | # If _PC_CHOWN_RESTRICTED is not set, does the full test of each |
692 | # directory anyway. |
693 | |
28d6a1e0 |
694 | # Takes optional second arg as scalar ref to error reason |
0e939f40 |
695 | |
262eb13a |
696 | sub _is_verysafe { |
697 | |
698 | # Need POSIX - but only want to bother if really necessary due to overhead |
699 | require POSIX; |
700 | |
701 | my $path = shift; |
28d6a1e0 |
702 | print "_is_verysafe testing $path\n" if $DEBUG; |
669b450a |
703 | return 1 if $^O eq 'VMS'; # owner delete control at file level |
262eb13a |
704 | |
28d6a1e0 |
705 | my $err_ref = shift; |
0e939f40 |
706 | |
262eb13a |
707 | # Should Get the value of _PC_CHOWN_RESTRICTED if it is defined |
708 | # and If it is not there do the extensive test |
709 | my $chown_restricted; |
710 | $chown_restricted = &POSIX::_PC_CHOWN_RESTRICTED() |
711 | if eval { &POSIX::_PC_CHOWN_RESTRICTED(); 1}; |
712 | |
713 | # If chown_resticted is set to some value we should test it |
714 | if (defined $chown_restricted) { |
715 | |
716 | # Return if the current directory is safe |
28d6a1e0 |
717 | return _is_safe($path,$err_ref) if POSIX::sysconf( $chown_restricted ); |
262eb13a |
718 | |
719 | } |
720 | |
721 | # To reach this point either, the _PC_CHOWN_RESTRICTED symbol |
722 | # was not avialable or the symbol was there but chown giveaway |
723 | # is allowed. Either way, we now have to test the entire tree for |
724 | # safety. |
725 | |
726 | # Convert path to an absolute directory if required |
727 | unless (File::Spec->file_name_is_absolute($path)) { |
728 | $path = File::Spec->rel2abs($path); |
729 | } |
730 | |
731 | # Split directory into components - assume no file |
732 | my ($volume, $directories, undef) = File::Spec->splitpath( $path, 1); |
733 | |
734 | # Slightly less efficient than having a a function in File::Spec |
735 | # to chop off the end of a directory or even a function that |
736 | # can handle ../ in a directory tree |
737 | # Sometimes splitdir() returns a blank at the end |
738 | # so we will probably check the bottom directory twice in some cases |
739 | my @dirs = File::Spec->splitdir($directories); |
740 | |
741 | # Concatenate one less directory each time around |
742 | foreach my $pos (0.. $#dirs) { |
743 | # Get a directory name |
744 | my $dir = File::Spec->catpath($volume, |
745 | File::Spec->catdir(@dirs[0.. $#dirs - $pos]), |
746 | '' |
747 | ); |
748 | |
749 | print "TESTING DIR $dir\n" if $DEBUG; |
750 | |
751 | # Check the directory |
28d6a1e0 |
752 | return 0 unless _is_safe($dir,$err_ref); |
262eb13a |
753 | |
754 | } |
755 | |
756 | return 1; |
757 | } |
758 | |
759 | |
760 | |
761 | # internal routine to determine whether unlink works on this |
762 | # platform for files that are currently open. |
763 | # Returns true if we can, false otherwise. |
764 | |
669b450a |
765 | # Currently WinNT, OS/2 and VMS can not unlink an opened file |
766 | # On VMS this is because the O_EXCL flag is used to open the |
767 | # temporary file. Currently I do not know enough about the issues |
768 | # on VMS to decide whether O_EXCL is a requirement. |
262eb13a |
769 | |
770 | sub _can_unlink_opened_file { |
771 | |
e77f578c |
772 | if ($^O eq 'MSWin32' || $^O eq 'os2' || $^O eq 'VMS' || $^O eq 'dos') { |
1c19c868 |
773 | return 0; |
774 | } else { |
775 | return 1; |
776 | } |
262eb13a |
777 | |
778 | } |
779 | |
1c19c868 |
780 | # internal routine to decide which security levels are allowed |
781 | # see safe_level() for more information on this |
782 | |
783 | # Controls whether the supplied security level is allowed |
784 | |
785 | # $cando = _can_do_level( $level ) |
786 | |
787 | sub _can_do_level { |
788 | |
789 | # Get security level |
790 | my $level = shift; |
791 | |
792 | # Always have to be able to do STANDARD |
793 | return 1 if $level == STANDARD; |
794 | |
795 | # Currently, the systems that can do HIGH or MEDIUM are identical |
6bbf1b34 |
796 | if ( $^O eq 'MSWin32' || $^O eq 'os2' || $^O eq 'cygwin' || $^O eq 'dos') { |
1c19c868 |
797 | return 0; |
798 | } else { |
799 | return 1; |
800 | } |
801 | |
802 | } |
262eb13a |
803 | |
804 | # This routine sets up a deferred unlinking of a specified |
805 | # filename and filehandle. It is used in the following cases: |
669b450a |
806 | # - Called by unlink0 if an opened file can not be unlinked |
262eb13a |
807 | # - Called by tempfile() if files are to be removed on shutdown |
808 | # - Called by tempdir() if directories are to be removed on shutdown |
809 | |
810 | # Arguments: |
811 | # _deferred_unlink( $fh, $fname, $isdir ); |
812 | # |
813 | # - filehandle (so that it can be expclicitly closed if open |
814 | # - filename (the thing we want to remove) |
815 | # - isdir (flag to indicate that we are being given a directory) |
816 | # [and hence no filehandle] |
817 | |
51fc852f |
818 | # Status is not referred to since all the magic is done with an END block |
262eb13a |
819 | |
1c19c868 |
820 | { |
821 | # Will set up two lexical variables to contain all the files to be |
822 | # removed. One array for files, another for directories |
823 | # They will only exist in this block |
824 | # This means we only have to set up a single END block to remove all files |
825 | # @files_to_unlink contains an array ref with the filehandle and filename |
826 | my (@files_to_unlink, @dirs_to_unlink); |
827 | |
828 | # Set up an end block to use these arrays |
829 | END { |
830 | # Files |
831 | foreach my $file (@files_to_unlink) { |
832 | # close the filehandle without checking its state |
833 | # in order to make real sure that this is closed |
834 | # if its already closed then I dont care about the answer |
835 | # probably a better way to do this |
836 | close($file->[0]); # file handle is [0] |
837 | |
838 | if (-f $file->[1]) { # file name is [1] |
839 | unlink $file->[1] or warn "Error removing ".$file->[1]; |
840 | } |
841 | } |
842 | # Dirs |
843 | foreach my $dir (@dirs_to_unlink) { |
844 | if (-d $dir) { |
845 | rmtree($dir, $DEBUG, 1); |
846 | } |
847 | } |
262eb13a |
848 | |
1c19c868 |
849 | } |
262eb13a |
850 | |
1c19c868 |
851 | # This is the sub called to register a file for deferred unlinking |
852 | # This could simply store the input parameters and defer everything |
853 | # until the END block. For now we do a bit of checking at this |
854 | # point in order to make sure that (1) we have a file/dir to delete |
855 | # and (2) we have been called with the correct arguments. |
856 | sub _deferred_unlink { |
857 | |
858 | croak 'Usage: _deferred_unlink($fh, $fname, $isdir)' |
859 | unless scalar(@_) == 3; |
669b450a |
860 | |
1c19c868 |
861 | my ($fh, $fname, $isdir) = @_; |
262eb13a |
862 | |
1c19c868 |
863 | warn "Setting up deferred removal of $fname\n" |
864 | if $DEBUG; |
669b450a |
865 | |
1c19c868 |
866 | # If we have a directory, check that it is a directory |
867 | if ($isdir) { |
262eb13a |
868 | |
1c19c868 |
869 | if (-d $fname) { |
262eb13a |
870 | |
1c19c868 |
871 | # Directory exists so store it |
51fc852f |
872 | # first on VMS turn []foo into [.foo] for rmtree |
873 | $fname = VMS::Filespec::vmspath($fname) if $^O eq 'VMS'; |
1c19c868 |
874 | push (@dirs_to_unlink, $fname); |
262eb13a |
875 | |
1c19c868 |
876 | } else { |
28d6a1e0 |
877 | carp "Request to remove directory $fname could not be completed since it does not exist!\n" if $^W; |
1c19c868 |
878 | } |
879 | |
262eb13a |
880 | } else { |
262eb13a |
881 | |
1c19c868 |
882 | if (-f $fname) { |
262eb13a |
883 | |
1c19c868 |
884 | # file exists so store handle and name for later removal |
885 | push(@files_to_unlink, [$fh, $fname]); |
262eb13a |
886 | |
1c19c868 |
887 | } else { |
28d6a1e0 |
888 | carp "Request to remove file $fname could not be completed since it is not there!\n" if $^W; |
1c19c868 |
889 | } |
262eb13a |
890 | |
262eb13a |
891 | } |
892 | |
262eb13a |
893 | } |
894 | |
262eb13a |
895 | |
1c19c868 |
896 | } |
262eb13a |
897 | |
898 | =head1 FUNCTIONS |
899 | |
900 | This section describes the recommended interface for generating |
901 | temporary files and directories. |
902 | |
903 | =over 4 |
904 | |
905 | =item B<tempfile> |
906 | |
907 | This is the basic function to generate temporary files. |
908 | The behaviour of the file can be changed using various options: |
909 | |
910 | ($fh, $filename) = tempfile(); |
911 | |
912 | Create a temporary file in the directory specified for temporary |
913 | files, as specified by the tmpdir() function in L<File::Spec>. |
914 | |
915 | ($fh, $filename) = tempfile($template); |
916 | |
917 | Create a temporary file in the current directory using the supplied |
918 | template. Trailing `X' characters are replaced with random letters to |
919 | generate the filename. At least four `X' characters must be present |
920 | in the template. |
921 | |
922 | ($fh, $filename) = tempfile($template, SUFFIX => $suffix) |
923 | |
924 | Same as previously, except that a suffix is added to the template |
925 | after the `X' translation. Useful for ensuring that a temporary |
926 | filename has a particular extension when needed by other applications. |
927 | But see the WARNING at the end. |
928 | |
929 | ($fh, $filename) = tempfile($template, DIR => $dir); |
930 | |
931 | Translates the template as before except that a directory name |
932 | is specified. |
933 | |
51fc852f |
934 | ($fh, $filename) = tempfile($template, UNLINK => 1); |
935 | |
936 | Return the filename and filehandle as before except that the file is |
937 | automatically removed when the program exits. Default is for the file |
938 | to be removed if a file handle is requested and to be kept if the |
09d7a2f9 |
939 | filename is requested. In a scalar context (where no filename is |
940 | returned) the file is always deleted either on exit or when it is closed. |
51fc852f |
941 | |
262eb13a |
942 | If the template is not specified, a template is always |
943 | automatically generated. This temporary file is placed in tmpdir() |
944 | (L<File::Spec>) unless a directory is specified explicitly with the |
945 | DIR option. |
946 | |
947 | $fh = tempfile( $template, DIR => $dir ); |
948 | |
949 | If called in scalar context, only the filehandle is returned |
950 | and the file will automatically be deleted when closed (see |
951 | the description of tmpfile() elsewhere in this document). |
952 | This is the preferred mode of operation, as if you only |
953 | have a filehandle, you can never create a race condition |
954 | by fumbling with the filename. On systems that can not unlink |
09d7a2f9 |
955 | an open file or can not mark a file as temporary when it is opened |
956 | (for example, Windows NT uses the C<O_TEMPORARY> flag)) |
957 | the file is marked for deletion when the program ends (equivalent |
958 | to setting UNLINK to 1). The C<UNLINK> flag is ignored if present. |
959 | |
262eb13a |
960 | (undef, $filename) = tempfile($template, OPEN => 0); |
961 | |
962 | This will return the filename based on the template but |
963 | will not open this file. Cannot be used in conjunction with |
964 | UNLINK set to true. Default is to always open the file |
965 | to protect from possible race conditions. A warning is issued |
966 | if warnings are turned on. Consider using the tmpnam() |
967 | and mktemp() functions described elsewhere in this document |
968 | if opening the file is not required. |
969 | |
51fc852f |
970 | Options can be combined as required. |
971 | |
262eb13a |
972 | =cut |
973 | |
974 | sub tempfile { |
975 | |
976 | # Can not check for argument count since we can have any |
977 | # number of args |
978 | |
979 | # Default options |
980 | my %options = ( |
981 | "DIR" => undef, # Directory prefix |
f826e675 |
982 | "SUFFIX" => '', # Template suffix |
983 | "UNLINK" => 0, # Do not unlink file on exit |
984 | "OPEN" => 1, # Open file |
262eb13a |
985 | ); |
986 | |
987 | # Check to see whether we have an odd or even number of arguments |
988 | my $template = (scalar(@_) % 2 == 1 ? shift(@_) : undef); |
989 | |
990 | # Read the options and merge with defaults |
991 | %options = (%options, @_) if @_; |
992 | |
993 | # First decision is whether or not to open the file |
994 | if (! $options{"OPEN"}) { |
995 | |
996 | warn "tempfile(): temporary filename requested but not opened.\nPossibly unsafe, consider using tempfile() with OPEN set to true\n" |
997 | if $^W; |
998 | |
999 | } |
1000 | |
f826e675 |
1001 | if ($options{"DIR"} and $^O eq 'VMS') { |
1002 | |
1003 | # on VMS turn []foo into [.foo] for concatenation |
1004 | $options{"DIR"} = VMS::Filespec::vmspath($options{"DIR"}); |
1005 | } |
1006 | |
669b450a |
1007 | # Construct the template |
262eb13a |
1008 | |
1009 | # Have a choice of trying to work around the mkstemp/mktemp/tmpnam etc |
1010 | # functions or simply constructing a template and using _gettemp() |
1011 | # explicitly. Go for the latter |
1012 | |
1013 | # First generate a template if not defined and prefix the directory |
1014 | # If no template must prefix the temp directory |
1015 | if (defined $template) { |
1016 | if ($options{"DIR"}) { |
1017 | |
1018 | $template = File::Spec->catfile($options{"DIR"}, $template); |
1019 | |
1020 | } |
1021 | |
1022 | } else { |
1023 | |
1024 | if ($options{"DIR"}) { |
1025 | |
1026 | $template = File::Spec->catfile($options{"DIR"}, TEMPXXX); |
1027 | |
1028 | } else { |
669b450a |
1029 | |
262eb13a |
1030 | $template = File::Spec->catfile(File::Spec->tmpdir, TEMPXXX); |
1031 | |
1032 | } |
669b450a |
1033 | |
262eb13a |
1034 | } |
1035 | |
1036 | # Now add a suffix |
1037 | $template .= $options{"SUFFIX"}; |
1038 | |
09d7a2f9 |
1039 | # Determine whether we should tell _gettemp to unlink the file |
1040 | # On unix this is irrelevant and can be worked out after the file is |
1041 | # opened (simply by unlinking the open filehandle). On Windows or VMS |
1042 | # we have to indicate temporary-ness when we open the file. In general |
1043 | # we only want a true temporary file if we are returning just the |
1044 | # filehandle - if the user wants the filename they probably do not |
1045 | # want the file to disappear as soon as they close it. |
1046 | # For this reason, tie unlink_on_close to the return context regardless |
1047 | # of OS. |
1048 | my $unlink_on_close = ( wantarray ? 0 : 1); |
1049 | |
262eb13a |
1050 | # Create the file |
28d6a1e0 |
1051 | my ($fh, $path, $errstr); |
1052 | croak "Error in tempfile() using $template: $errstr" |
262eb13a |
1053 | unless (($fh, $path) = _gettemp($template, |
51fc852f |
1054 | "open" => $options{'OPEN'}, |
262eb13a |
1055 | "mkdir"=> 0 , |
09d7a2f9 |
1056 | "unlink_on_close" => $unlink_on_close, |
262eb13a |
1057 | "suffixlen" => length($options{'SUFFIX'}), |
28d6a1e0 |
1058 | "ErrStr" => \$errstr, |
669b450a |
1059 | ) ); |
262eb13a |
1060 | |
1061 | # Set up an exit handler that can do whatever is right for the |
09d7a2f9 |
1062 | # system. This removes files at exit when requested explicitly or when |
1063 | # system is asked to unlink_on_close but is unable to do so because |
1064 | # of OS limitations. |
1065 | # The latter should be achieved by using a tied filehandle. |
1066 | # Do not check return status since this is all done with END blocks. |
262eb13a |
1067 | _deferred_unlink($fh, $path, 0) if $options{"UNLINK"}; |
669b450a |
1068 | |
262eb13a |
1069 | # Return |
1070 | if (wantarray()) { |
1071 | |
1072 | if ($options{'OPEN'}) { |
1073 | return ($fh, $path); |
1074 | } else { |
1075 | return (undef, $path); |
1076 | } |
1077 | |
1078 | } else { |
1079 | |
1080 | # Unlink the file. It is up to unlink0 to decide what to do with |
1081 | # this (whether to unlink now or to defer until later) |
1082 | unlink0($fh, $path) or croak "Error unlinking file $path using unlink0"; |
669b450a |
1083 | |
262eb13a |
1084 | # Return just the filehandle. |
1085 | return $fh; |
1086 | } |
1087 | |
1088 | |
1089 | } |
1090 | |
1091 | =item B<tempdir> |
1092 | |
1093 | This is the recommended interface for creation of temporary directories. |
1094 | The behaviour of the function depends on the arguments: |
1095 | |
1096 | $tempdir = tempdir(); |
1097 | |
1098 | Create a directory in tmpdir() (see L<File::Spec|File::Spec>). |
1099 | |
1100 | $tempdir = tempdir( $template ); |
1101 | |
1102 | Create a directory from the supplied template. This template is |
1103 | similar to that described for tempfile(). `X' characters at the end |
1104 | of the template are replaced with random letters to construct the |
1105 | directory name. At least four `X' characters must be in the template. |
1106 | |
1107 | $tempdir = tempdir ( DIR => $dir ); |
1108 | |
1109 | Specifies the directory to use for the temporary directory. |
1110 | The temporary directory name is derived from an internal template. |
1111 | |
1112 | $tempdir = tempdir ( $template, DIR => $dir ); |
1113 | |
1114 | Prepend the supplied directory name to the template. The template |
1115 | should not include parent directory specifications itself. Any parent |
1116 | directory specifications are removed from the template before |
1117 | prepending the supplied directory. |
1118 | |
1119 | $tempdir = tempdir ( $template, TMPDIR => 1 ); |
1120 | |
1121 | Using the supplied template, creat the temporary directory in |
1122 | a standard location for temporary files. Equivalent to doing |
1123 | |
1124 | $tempdir = tempdir ( $template, DIR => File::Spec->tmpdir); |
1125 | |
1126 | but shorter. Parent directory specifications are stripped from the |
1127 | template itself. The C<TMPDIR> option is ignored if C<DIR> is set |
1128 | explicitly. Additionally, C<TMPDIR> is implied if neither a template |
1129 | nor a directory are supplied. |
1130 | |
1131 | $tempdir = tempdir( $template, CLEANUP => 1); |
1132 | |
1133 | Create a temporary directory using the supplied template, but |
1134 | attempt to remove it (and all files inside it) when the program |
1135 | exits. Note that an attempt will be made to remove all files from |
1136 | the directory even if they were not created by this module (otherwise |
1137 | why ask to clean it up?). The directory removal is made with |
1138 | the rmtree() function from the L<File::Path|File::Path> module. |
1139 | Of course, if the template is not specified, the temporary directory |
1140 | will be created in tmpdir() and will also be removed at program exit. |
1141 | |
1142 | =cut |
1143 | |
1144 | # ' |
1145 | |
1146 | sub tempdir { |
1147 | |
1148 | # Can not check for argument count since we can have any |
1149 | # number of args |
1150 | |
1151 | # Default options |
1152 | my %options = ( |
1153 | "CLEANUP" => 0, # Remove directory on exit |
1154 | "DIR" => '', # Root directory |
1155 | "TMPDIR" => 0, # Use tempdir with template |
1156 | ); |
1157 | |
1158 | # Check to see whether we have an odd or even number of arguments |
1159 | my $template = (scalar(@_) % 2 == 1 ? shift(@_) : undef ); |
1160 | |
1161 | # Read the options and merge with defaults |
1162 | %options = (%options, @_) if @_; |
1163 | |
1164 | # Modify or generate the template |
1165 | |
1166 | # Deal with the DIR and TMPDIR options |
1167 | if (defined $template) { |
1168 | |
1169 | # Need to strip directory path if using DIR or TMPDIR |
1170 | if ($options{'TMPDIR'} || $options{'DIR'}) { |
1171 | |
1172 | # Strip parent directory from the filename |
51fc852f |
1173 | # |
262eb13a |
1174 | # There is no filename at the end |
51fc852f |
1175 | $template = VMS::Filespec::vmspath($template) if $^O eq 'VMS'; |
262eb13a |
1176 | my ($volume, $directories, undef) = File::Spec->splitpath( $template, 1); |
1177 | |
1178 | # Last directory is then our template |
1179 | $template = (File::Spec->splitdir($directories))[-1]; |
1180 | |
1181 | # Prepend the supplied directory or temp dir |
1182 | if ($options{"DIR"}) { |
1183 | |
e4dfc136 |
1184 | $template = File::Spec->catdir($options{"DIR"}, $template); |
262eb13a |
1185 | |
1186 | } elsif ($options{TMPDIR}) { |
1187 | |
1188 | # Prepend tmpdir |
1189 | $template = File::Spec->catdir(File::Spec->tmpdir, $template); |
1190 | |
1191 | } |
1192 | |
1193 | } |
1194 | |
1195 | } else { |
1196 | |
1197 | if ($options{"DIR"}) { |
1198 | |
1199 | $template = File::Spec->catdir($options{"DIR"}, TEMPXXX); |
1200 | |
1201 | } else { |
669b450a |
1202 | |
262eb13a |
1203 | $template = File::Spec->catdir(File::Spec->tmpdir, TEMPXXX); |
1204 | |
1205 | } |
669b450a |
1206 | |
262eb13a |
1207 | } |
1208 | |
1209 | # Create the directory |
1210 | my $tempdir; |
669b450a |
1211 | my $suffixlen = 0; |
1212 | if ($^O eq 'VMS') { # dir names can end in delimiters |
1213 | $template =~ m/([\.\]:>]+)$/; |
1214 | $suffixlen = length($1); |
1215 | } |
0e939f40 |
1216 | |
28d6a1e0 |
1217 | my $errstr; |
1218 | croak "Error in tempdir() using $template: $errstr" |
262eb13a |
1219 | unless ((undef, $tempdir) = _gettemp($template, |
669b450a |
1220 | "open" => 0, |
262eb13a |
1221 | "mkdir"=> 1 , |
669b450a |
1222 | "suffixlen" => $suffixlen, |
28d6a1e0 |
1223 | "ErrStr" => \$errstr, |
669b450a |
1224 | ) ); |
1225 | |
262eb13a |
1226 | # Install exit handler; must be dynamic to get lexical |
669b450a |
1227 | if ( $options{'CLEANUP'} && -d $tempdir) { |
262eb13a |
1228 | _deferred_unlink(undef, $tempdir, 1); |
669b450a |
1229 | } |
262eb13a |
1230 | |
1231 | # Return the dir name |
1232 | return $tempdir; |
1233 | |
1234 | } |
1235 | |
1236 | =back |
1237 | |
1238 | =head1 MKTEMP FUNCTIONS |
1239 | |
1240 | The following functions are Perl implementations of the |
1241 | mktemp() family of temp file generation system calls. |
1242 | |
1243 | =over 4 |
1244 | |
1245 | =item B<mkstemp> |
1246 | |
1247 | Given a template, returns a filehandle to the temporary file and the name |
1248 | of the file. |
1249 | |
1250 | ($fh, $name) = mkstemp( $template ); |
1251 | |
1252 | In scalar context, just the filehandle is returned. |
1253 | |
1254 | The template may be any filename with some number of X's appended |
1255 | to it, for example F</tmp/temp.XXXX>. The trailing X's are replaced |
1256 | with unique alphanumeric combinations. |
1257 | |
1258 | =cut |
1259 | |
1260 | |
1261 | |
1262 | sub mkstemp { |
1263 | |
1264 | croak "Usage: mkstemp(template)" |
1265 | if scalar(@_) != 1; |
1266 | |
1267 | my $template = shift; |
1268 | |
28d6a1e0 |
1269 | my ($fh, $path, $errstr); |
1270 | croak "Error in mkstemp using $template: $errstr" |
669b450a |
1271 | unless (($fh, $path) = _gettemp($template, |
1272 | "open" => 1, |
262eb13a |
1273 | "mkdir"=> 0 , |
1274 | "suffixlen" => 0, |
28d6a1e0 |
1275 | "ErrStr" => \$errstr, |
262eb13a |
1276 | ) ); |
1277 | |
1278 | if (wantarray()) { |
1279 | return ($fh, $path); |
1280 | } else { |
1281 | return $fh; |
1282 | } |
1283 | |
1284 | } |
1285 | |
1286 | |
1287 | =item B<mkstemps> |
1288 | |
1289 | Similar to mkstemp(), except that an extra argument can be supplied |
1290 | with a suffix to be appended to the template. |
1291 | |
1292 | ($fh, $name) = mkstemps( $template, $suffix ); |
1293 | |
1294 | For example a template of C<testXXXXXX> and suffix of C<.dat> |
1295 | would generate a file similar to F<testhGji_w.dat>. |
1296 | |
1297 | Returns just the filehandle alone when called in scalar context. |
1298 | |
1299 | =cut |
1300 | |
1301 | sub mkstemps { |
1302 | |
1303 | croak "Usage: mkstemps(template, suffix)" |
1304 | if scalar(@_) != 2; |
1305 | |
1306 | |
1307 | my $template = shift; |
1308 | my $suffix = shift; |
1309 | |
1310 | $template .= $suffix; |
669b450a |
1311 | |
28d6a1e0 |
1312 | my ($fh, $path, $errstr); |
1313 | croak "Error in mkstemps using $template: $errstr" |
262eb13a |
1314 | unless (($fh, $path) = _gettemp($template, |
28d6a1e0 |
1315 | "open" => 1, |
262eb13a |
1316 | "mkdir"=> 0 , |
1317 | "suffixlen" => length($suffix), |
28d6a1e0 |
1318 | "ErrStr" => \$errstr, |
262eb13a |
1319 | ) ); |
1320 | |
1321 | if (wantarray()) { |
1322 | return ($fh, $path); |
1323 | } else { |
1324 | return $fh; |
1325 | } |
1326 | |
1327 | } |
1328 | |
1329 | =item B<mkdtemp> |
1330 | |
1331 | Create a directory from a template. The template must end in |
1332 | X's that are replaced by the routine. |
1333 | |
1334 | $tmpdir_name = mkdtemp($template); |
1335 | |
1336 | Returns the name of the temporary directory created. |
1337 | Returns undef on failure. |
1338 | |
1339 | Directory must be removed by the caller. |
1340 | |
1341 | =cut |
1342 | |
1343 | #' # for emacs |
1344 | |
1345 | sub mkdtemp { |
1346 | |
1347 | croak "Usage: mkdtemp(template)" |
1348 | if scalar(@_) != 1; |
262eb13a |
1349 | |
669b450a |
1350 | my $template = shift; |
1351 | my $suffixlen = 0; |
1352 | if ($^O eq 'VMS') { # dir names can end in delimiters |
1353 | $template =~ m/([\.\]:>]+)$/; |
1354 | $suffixlen = length($1); |
1355 | } |
28d6a1e0 |
1356 | my ($junk, $tmpdir, $errstr); |
1357 | croak "Error creating temp directory from template $template\: $errstr" |
262eb13a |
1358 | unless (($junk, $tmpdir) = _gettemp($template, |
669b450a |
1359 | "open" => 0, |
262eb13a |
1360 | "mkdir"=> 1 , |
669b450a |
1361 | "suffixlen" => $suffixlen, |
28d6a1e0 |
1362 | "ErrStr" => \$errstr, |
262eb13a |
1363 | ) ); |
1364 | |
1365 | return $tmpdir; |
1366 | |
1367 | } |
1368 | |
1369 | =item B<mktemp> |
1370 | |
1371 | Returns a valid temporary filename but does not guarantee |
1372 | that the file will not be opened by someone else. |
1373 | |
1374 | $unopened_file = mktemp($template); |
1375 | |
1376 | Template is the same as that required by mkstemp(). |
1377 | |
1378 | =cut |
1379 | |
1380 | sub mktemp { |
1381 | |
1382 | croak "Usage: mktemp(template)" |
1383 | if scalar(@_) != 1; |
1384 | |
1385 | my $template = shift; |
1386 | |
28d6a1e0 |
1387 | my ($tmpname, $junk, $errstr); |
1388 | croak "Error getting name to temp file from template $template: $errstr" |
262eb13a |
1389 | unless (($junk, $tmpname) = _gettemp($template, |
669b450a |
1390 | "open" => 0, |
262eb13a |
1391 | "mkdir"=> 0 , |
1392 | "suffixlen" => 0, |
28d6a1e0 |
1393 | "ErrStr" => \$errstr, |
262eb13a |
1394 | ) ); |
1395 | |
1396 | return $tmpname; |
1397 | } |
1398 | |
1399 | =back |
1400 | |
1401 | =head1 POSIX FUNCTIONS |
1402 | |
1403 | This section describes the re-implementation of the tmpnam() |
1404 | and tmpfile() functions described in L<POSIX> |
1405 | using the mkstemp() from this module. |
1406 | |
1407 | Unlike the L<POSIX|POSIX> implementations, the directory used |
1408 | for the temporary file is not specified in a system include |
1409 | file (C<P_tmpdir>) but simply depends on the choice of tmpdir() |
1410 | returned by L<File::Spec|File::Spec>. On some implementations this |
1411 | location can be set using the C<TMPDIR> environment variable, which |
1412 | may not be secure. |
1413 | If this is a problem, simply use mkstemp() and specify a template. |
1414 | |
1415 | =over 4 |
1416 | |
1417 | =item B<tmpnam> |
1418 | |
1419 | When called in scalar context, returns the full name (including path) |
1420 | of a temporary file (uses mktemp()). The only check is that the file does |
1421 | not already exist, but there is no guarantee that that condition will |
1422 | continue to apply. |
1423 | |
1424 | $file = tmpnam(); |
1425 | |
1426 | When called in list context, a filehandle to the open file and |
1427 | a filename are returned. This is achieved by calling mkstemp() |
1428 | after constructing a suitable template. |
1429 | |
1430 | ($fh, $file) = tmpnam(); |
1431 | |
1432 | If possible, this form should be used to prevent possible |
1433 | race conditions. |
1434 | |
1435 | See L<File::Spec/tmpdir> for information on the choice of temporary |
1436 | directory for a particular operating system. |
1437 | |
1438 | =cut |
1439 | |
1440 | sub tmpnam { |
1441 | |
1442 | # Retrieve the temporary directory name |
1443 | my $tmpdir = File::Spec->tmpdir; |
1444 | |
1445 | croak "Error temporary directory is not writable" |
1446 | if $tmpdir eq ''; |
1447 | |
1448 | # Use a ten character template and append to tmpdir |
1449 | my $template = File::Spec->catfile($tmpdir, TEMPXXX); |
669b450a |
1450 | |
262eb13a |
1451 | if (wantarray() ) { |
1452 | return mkstemp($template); |
1453 | } else { |
1454 | return mktemp($template); |
1455 | } |
1456 | |
1457 | } |
1458 | |
1459 | =item B<tmpfile> |
1460 | |
1461 | In scalar context, returns the filehandle of a temporary file. |
1462 | |
1463 | $fh = tmpfile(); |
1464 | |
1465 | The file is removed when the filehandle is closed or when the program |
1466 | exits. No access to the filename is provided. |
1467 | |
0e939f40 |
1468 | If the temporary file can not be created undef is returned. |
1469 | Currently this command will probably not work when the temporary |
1470 | directory is on an NFS file system. |
1471 | |
262eb13a |
1472 | =cut |
1473 | |
1474 | sub tmpfile { |
1475 | |
91e74348 |
1476 | # Simply call tmpnam() in a list context |
262eb13a |
1477 | my ($fh, $file) = tmpnam(); |
1478 | |
1479 | # Make sure file is removed when filehandle is closed |
0e939f40 |
1480 | # This will fail on NFS |
1481 | unlink0($fh, $file) |
1482 | or return undef; |
262eb13a |
1483 | |
1484 | return $fh; |
1485 | |
1486 | } |
1487 | |
1488 | =back |
1489 | |
1490 | =head1 ADDITIONAL FUNCTIONS |
1491 | |
1492 | These functions are provided for backwards compatibility |
1493 | with common tempfile generation C library functions. |
1494 | |
1495 | They are not exported and must be addressed using the full package |
1496 | name. |
1497 | |
1498 | =over 4 |
1499 | |
1500 | =item B<tempnam> |
1501 | |
1502 | Return the name of a temporary file in the specified directory |
1503 | using a prefix. The file is guaranteed not to exist at the time |
1504 | the function was called, but such guarantees are good for one |
1505 | clock tick only. Always use the proper form of C<sysopen> |
1506 | with C<O_CREAT | O_EXCL> if you must open such a filename. |
1507 | |
1508 | $filename = File::Temp::tempnam( $dir, $prefix ); |
1509 | |
1510 | Equivalent to running mktemp() with $dir/$prefixXXXXXXXX |
1511 | (using unix file convention as an example) |
1512 | |
1513 | Because this function uses mktemp(), it can suffer from race conditions. |
1514 | |
1515 | =cut |
1516 | |
1517 | sub tempnam { |
1518 | |
1519 | croak 'Usage tempnam($dir, $prefix)' unless scalar(@_) == 2; |
1520 | |
1521 | my ($dir, $prefix) = @_; |
1522 | |
1523 | # Add a string to the prefix |
1524 | $prefix .= 'XXXXXXXX'; |
1525 | |
1526 | # Concatenate the directory to the file |
1527 | my $template = File::Spec->catfile($dir, $prefix); |
1528 | |
1529 | return mktemp($template); |
1530 | |
1531 | } |
1532 | |
1533 | =back |
1534 | |
1535 | =head1 UTILITY FUNCTIONS |
1536 | |
1537 | Useful functions for dealing with the filehandle and filename. |
1538 | |
1539 | =over 4 |
1540 | |
1541 | =item B<unlink0> |
1542 | |
1543 | Given an open filehandle and the associated filename, make a safe |
1544 | unlink. This is achieved by first checking that the filename and |
1545 | filehandle initially point to the same file and that the number of |
1546 | links to the file is 1 (all fields returned by stat() are compared). |
1547 | Then the filename is unlinked and the filehandle checked once again to |
1548 | verify that the number of links on that file is now 0. This is the |
1549 | closest you can come to making sure that the filename unlinked was the |
1550 | same as the file whose descriptor you hold. |
1551 | |
1552 | unlink0($fh, $path) or die "Error unlinking file $path safely"; |
1553 | |
1554 | Returns false on error. The filehandle is not closed since on some |
1555 | occasions this is not required. |
1556 | |
1557 | On some platforms, for example Windows NT, it is not possible to |
1558 | unlink an open file (the file must be closed first). On those |
1c19c868 |
1559 | platforms, the actual unlinking is deferred until the program ends and |
1560 | good status is returned. A check is still performed to make sure that |
1561 | the filehandle and filename are pointing to the same thing (but not at |
1562 | the time the end block is executed since the deferred removal may not |
1563 | have access to the filehandle). |
262eb13a |
1564 | |
1565 | Additionally, on Windows NT not all the fields returned by stat() can |
51fc852f |
1566 | be compared. For example, the C<dev> and C<rdev> fields seem to be |
1567 | different. Also, it seems that the size of the file returned by stat() |
262eb13a |
1568 | does not always agree, with C<stat(FH)> being more accurate than |
1569 | C<stat(filename)>, presumably because of caching issues even when |
1570 | using autoflush (this is usually overcome by waiting a while after |
1571 | writing to the tempfile before attempting to C<unlink0> it). |
1572 | |
1c19c868 |
1573 | Finally, on NFS file systems the link count of the file handle does |
1574 | not always go to zero immediately after unlinking. Currently, this |
1575 | command is expected to fail on NFS disks. |
1576 | |
262eb13a |
1577 | =cut |
1578 | |
1579 | sub unlink0 { |
1580 | |
1581 | croak 'Usage: unlink0(filehandle, filename)' |
1582 | unless scalar(@_) == 2; |
1583 | |
1584 | # Read args |
1585 | my ($fh, $path) = @_; |
1586 | |
1587 | warn "Unlinking $path using unlink0\n" |
1588 | if $DEBUG; |
1589 | |
1590 | # Stat the filehandle |
1591 | my @fh = stat $fh; |
1592 | |
1593 | if ($fh[3] > 1 && $^W) { |
28d6a1e0 |
1594 | carp "unlink0: fstat found too many links; SB=@fh" if $^W; |
669b450a |
1595 | } |
262eb13a |
1596 | |
1597 | # Stat the path |
1598 | my @path = stat $path; |
1599 | |
1600 | unless (@path) { |
1601 | carp "unlink0: $path is gone already" if $^W; |
1602 | return; |
669b450a |
1603 | } |
262eb13a |
1604 | |
1605 | # this is no longer a file, but may be a directory, or worse |
1606 | unless (-f _) { |
1607 | confess "panic: $path is no longer a file: SB=@fh"; |
669b450a |
1608 | } |
262eb13a |
1609 | |
1610 | # Do comparison of each member of the array |
1611 | # On WinNT dev and rdev seem to be different |
1612 | # depending on whether it is a file or a handle. |
1613 | # Cannot simply compare all members of the stat return |
1614 | # Select the ones we can use |
1615 | my @okstat = (0..$#fh); # Use all by default |
1616 | if ($^O eq 'MSWin32') { |
1617 | @okstat = (1,2,3,4,5,7,8,9,10); |
669b450a |
1618 | } elsif ($^O eq 'os2') { |
d62e1b7f |
1619 | @okstat = (0, 2..$#fh); |
51fc852f |
1620 | } elsif ($^O eq 'VMS') { # device and file ID are sufficient |
1621 | @okstat = (0, 1); |
6bbf1b34 |
1622 | } elsif ($^O eq 'dos') { |
1623 | @okstat = (0,2..7,11..$#fh); |
262eb13a |
1624 | } |
1625 | |
1626 | # Now compare each entry explicitly by number |
1627 | for (@okstat) { |
1628 | print "Comparing: $_ : $fh[$_] and $path[$_]\n" if $DEBUG; |
d62e1b7f |
1629 | # Use eq rather than == since rdev, blksize, and blocks (6, 11, |
1630 | # and 12) will be '' on platforms that do not support them. This |
1631 | # is fine since we are only comparing integers. |
669b450a |
1632 | unless ($fh[$_] eq $path[$_]) { |
262eb13a |
1633 | warn "Did not match $_ element of stat\n" if $DEBUG; |
1634 | return 0; |
1635 | } |
1636 | } |
669b450a |
1637 | |
262eb13a |
1638 | # attempt remove the file (does not work on some platforms) |
1639 | if (_can_unlink_opened_file()) { |
1640 | # XXX: do *not* call this on a directory; possible race |
1641 | # resulting in recursive removal |
1642 | croak "unlink0: $path has become a directory!" if -d $path; |
1643 | unlink($path) or return 0; |
1644 | |
1645 | # Stat the filehandle |
1646 | @fh = stat $fh; |
1647 | |
1648 | print "Link count = $fh[3] \n" if $DEBUG; |
1649 | |
1650 | # Make sure that the link count is zero |
ceb977da |
1651 | # - Cygwin provides deferred unlinking, however, |
1652 | # on Win9x the link count remains 1 |
0e939f40 |
1653 | # On NFS the link count may still be 1 but we cant know that |
1654 | # we are on NFS |
ceb977da |
1655 | return ( $fh[3] == 0 or $^O eq 'cygwin' ? 1 : 0); |
262eb13a |
1656 | |
1657 | } else { |
1658 | _deferred_unlink($fh, $path, 0); |
1659 | return 1; |
1660 | } |
1661 | |
1662 | } |
1663 | |
1664 | =back |
1665 | |
1666 | =head1 PACKAGE VARIABLES |
1667 | |
1668 | These functions control the global state of the package. |
1669 | |
1670 | =over 4 |
1671 | |
1672 | =item B<safe_level> |
1673 | |
1674 | Controls the lengths to which the module will go to check the safety of the |
1675 | temporary file or directory before proceeding. |
1676 | Options are: |
1677 | |
1678 | =over 8 |
1679 | |
1680 | =item STANDARD |
1681 | |
1682 | Do the basic security measures to ensure the directory exists and |
1683 | is writable, that the umask() is fixed before opening of the file, |
1684 | that temporary files are opened only if they do not already exist, and |
1685 | that possible race conditions are avoided. Finally the L<unlink0|"unlink0"> |
1686 | function is used to remove files safely. |
1687 | |
1688 | =item MEDIUM |
1689 | |
1690 | In addition to the STANDARD security, the output directory is checked |
1691 | to make sure that it is owned either by root or the user running the |
1692 | program. If the directory is writable by group or by other, it is then |
1693 | checked to make sure that the sticky bit is set. |
1694 | |
1695 | Will not work on platforms that do not support the C<-k> test |
1696 | for sticky bit. |
1697 | |
1698 | =item HIGH |
1699 | |
1700 | In addition to the MEDIUM security checks, also check for the |
1701 | possibility of ``chown() giveaway'' using the L<POSIX|POSIX> |
1702 | sysconf() function. If this is a possibility, each directory in the |
1703 | path is checked in turn for safeness, recursively walking back to the |
1704 | root directory. |
1705 | |
1706 | For platforms that do not support the L<POSIX|POSIX> |
1707 | C<_PC_CHOWN_RESTRICTED> symbol (for example, Windows NT) it is |
1708 | assumed that ``chown() giveaway'' is possible and the recursive test |
1709 | is performed. |
1710 | |
1711 | =back |
1712 | |
1713 | The level can be changed as follows: |
1714 | |
1715 | File::Temp->safe_level( File::Temp::HIGH ); |
1716 | |
1717 | The level constants are not exported by the module. |
1718 | |
1719 | Currently, you must be running at least perl v5.6.0 in order to |
1720 | run with MEDIUM or HIGH security. This is simply because the |
1721 | safety tests use functions from L<Fcntl|Fcntl> that are not |
1722 | available in older versions of perl. The problem is that the version |
1723 | number for Fcntl is the same in perl 5.6.0 and in 5.005_03 even though |
1c19c868 |
1724 | they are different versions. |
1725 | |
1726 | On systems that do not support the HIGH or MEDIUM safety levels |
1727 | (for example Win NT or OS/2) any attempt to change the level will |
1728 | be ignored. The decision to ignore rather than raise an exception |
1729 | allows portable programs to be written with high security in mind |
1730 | for the systems that can support this without those programs failing |
1731 | on systems where the extra tests are irrelevant. |
1732 | |
1733 | If you really need to see whether the change has been accepted |
1734 | simply examine the return value of C<safe_level>. |
1735 | |
1736 | $newlevel = File::Temp->safe_level( File::Temp::HIGH ); |
1737 | die "Could not change to high security" |
1738 | if $newlevel != File::Temp::HIGH; |
262eb13a |
1739 | |
1740 | =cut |
1741 | |
1742 | { |
1743 | # protect from using the variable itself |
1744 | my $LEVEL = STANDARD; |
1745 | sub safe_level { |
1746 | my $self = shift; |
1747 | if (@_) { |
1748 | my $level = shift; |
1749 | if (($level != STANDARD) && ($level != MEDIUM) && ($level != HIGH)) { |
28d6a1e0 |
1750 | carp "safe_level: Specified level ($level) not STANDARD, MEDIUM or HIGH - ignoring\n" if $^W; |
262eb13a |
1751 | } else { |
1c19c868 |
1752 | # Dont allow this on perl 5.005 or earlier |
262eb13a |
1753 | if ($] < 5.006 && $level != STANDARD) { |
1754 | # Cant do MEDIUM or HIGH checks |
1755 | croak "Currently requires perl 5.006 or newer to do the safe checks"; |
1756 | } |
1c19c868 |
1757 | # Check that we are allowed to change level |
1758 | # Silently ignore if we can not. |
1759 | $LEVEL = $level if _can_do_level($level); |
262eb13a |
1760 | } |
1761 | } |
1762 | return $LEVEL; |
1763 | } |
1764 | } |
1765 | |
1766 | =item TopSystemUID |
1767 | |
1768 | This is the highest UID on the current system that refers to a root |
1769 | UID. This is used to make sure that the temporary directory is |
1770 | owned by a system UID (C<root>, C<bin>, C<sys> etc) rather than |
1771 | simply by root. |
1772 | |
1773 | This is required since on many unix systems C</tmp> is not owned |
1774 | by root. |
1775 | |
1776 | Default is to assume that any UID less than or equal to 10 is a root |
1777 | UID. |
1778 | |
1779 | File::Temp->top_system_uid(10); |
1780 | my $topid = File::Temp->top_system_uid; |
1781 | |
1782 | This value can be adjusted to reduce security checking if required. |
1783 | The value is only relevant when C<safe_level> is set to MEDIUM or higher. |
1784 | |
1785 | =back |
1786 | |
1787 | =cut |
1788 | |
1789 | { |
1790 | my $TopSystemUID = 10; |
1791 | sub top_system_uid { |
1792 | my $self = shift; |
1793 | if (@_) { |
1794 | my $newuid = shift; |
1795 | croak "top_system_uid: UIDs should be numeric" |
1796 | unless $newuid =~ /^\d+$/s; |
1797 | $TopSystemUID = $newuid; |
1798 | } |
1799 | return $TopSystemUID; |
1800 | } |
1801 | } |
1802 | |
1803 | =head1 WARNING |
1804 | |
1805 | For maximum security, endeavour always to avoid ever looking at, |
1806 | touching, or even imputing the existence of the filename. You do not |
1807 | know that that filename is connected to the same file as the handle |
1808 | you have, and attempts to check this can only trigger more race |
1809 | conditions. It's far more secure to use the filehandle alone and |
1810 | dispense with the filename altogether. |
1811 | |
1812 | If you need to pass the handle to something that expects a filename |
1813 | then, on a unix system, use C<"/dev/fd/" . fileno($fh)> for arbitrary |
1814 | programs, or more generally C<< "+<=&" . fileno($fh) >> for Perl |
1815 | programs. You will have to clear the close-on-exec bit on that file |
1816 | descriptor before passing it to another process. |
1817 | |
1818 | use Fcntl qw/F_SETFD F_GETFD/; |
1819 | fcntl($tmpfh, F_SETFD, 0) |
1820 | or die "Can't clear close-on-exec flag on temp fh: $!\n"; |
1821 | |
09d7a2f9 |
1822 | =head2 Temporary files and NFS |
1823 | |
1824 | Some problems are associated with using temporary files that reside |
1825 | on NFS file systems and it is recommended that a local filesystem |
1826 | is used whenever possible. Some of the security tests will most probably |
1827 | fail when the temp file is not local. Additionally, be aware that |
1828 | the performance of I/O operations over NFS will not be as good as for |
1829 | a local disk. |
1830 | |
262eb13a |
1831 | =head1 HISTORY |
1832 | |
1833 | Originally began life in May 1999 as an XS interface to the system |
e77f578c |
1834 | mkstemp() function. In March 2000, the OpenBSD mkstemp() code was |
262eb13a |
1835 | translated to Perl for total control of the code's |
1836 | security checking, to ensure the presence of the function regardless of |
1837 | operating system and to help with portability. |
1838 | |
1839 | =head1 SEE ALSO |
1840 | |
1841 | L<POSIX/tmpnam>, L<POSIX/tmpfile>, L<File::Spec>, L<File::Path> |
1842 | |
09d7a2f9 |
1843 | See L<IO::File> and L<File::MkTemp> for different implementations of |
1844 | temporary file handling. |
262eb13a |
1845 | |
1846 | =head1 AUTHOR |
1847 | |
1848 | Tim Jenness E<lt>t.jenness@jach.hawaii.eduE<gt> |
1849 | |
0e939f40 |
1850 | Copyright (C) 1999-2001 Tim Jenness and the UK Particle Physics and |
262eb13a |
1851 | Astronomy Research Council. All Rights Reserved. This program is free |
1852 | software; you can redistribute it and/or modify it under the same |
1853 | terms as Perl itself. |
1854 | |
1855 | Original Perl implementation loosely based on the OpenBSD C code for |
1856 | mkstemp(). Thanks to Tom Christiansen for suggesting that this module |
1857 | should be written and providing ideas for code improvements and |
1858 | security enhancements. |
1859 | |
1860 | =cut |
1861 | |
1862 | |
1863 | 1; |