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262eb13a GS |
1 | package File::Temp; |
2 | ||
3 | =head1 NAME | |
4 | ||
5 | File::Temp - return name and handle of a temporary file safely | |
6 | ||
e77f578c JH |
7 | =begin __INTERNALS |
8 | ||
9 | =head1 PORTABILITY | |
10 | ||
11 | This module is designed to be portable across operating systems | |
be708cc0 JH |
12 | and it currently supports Unix, VMS, DOS, OS/2, Windows and |
13 | Mac OS (Classic). When | |
e77f578c JH |
14 | porting to a new OS there are generally three main issues |
15 | that have to be solved: | |
16 | ||
17 | =over 4 | |
18 | ||
19 | =item * | |
20 | ||
28d6a1e0 | 21 | Can the OS unlink an open file? If it can not then the |
e77f578c JH |
22 | C<_can_unlink_opened_file> method should be modified. |
23 | ||
24 | =item * | |
25 | ||
26 | Are the return values from C<stat> reliable? By default all the | |
27 | return values from C<stat> are compared when unlinking a temporary | |
28 | file using the filename and the handle. Operating systems other than | |
29 | unix do not always have valid entries in all fields. If C<unlink0> fails | |
30 | then the C<stat> comparison should be modified accordingly. | |
31 | ||
32 | =item * | |
33 | ||
34 | Security. Systems that can not support a test for the sticky bit | |
35 | on a directory can not use the MEDIUM and HIGH security tests. | |
36 | The C<_can_do_level> method should be modified accordingly. | |
37 | ||
38 | =back | |
39 | ||
40 | =end __INTERNALS | |
41 | ||
262eb13a GS |
42 | =head1 SYNOPSIS |
43 | ||
be708cc0 | 44 | use File::Temp qw/ tempfile tempdir /; |
262eb13a GS |
45 | |
46 | $dir = tempdir( CLEANUP => 1 ); | |
47 | ($fh, $filename) = tempfile( DIR => $dir ); | |
48 | ||
49 | ($fh, $filename) = tempfile( $template, DIR => $dir); | |
50 | ($fh, $filename) = tempfile( $template, SUFFIX => '.dat'); | |
51 | ||
52 | $fh = tempfile(); | |
53 | ||
4a094b80 JH |
54 | Object interface: |
55 | ||
56 | require File::Temp; | |
57 | use File::Temp (); | |
58 | ||
59 | $fh = new File::Temp($template); | |
60 | $fname = $fh->filename; | |
61 | ||
62 | $tmp = new File::Temp( UNLINK => 0, SUFFIX => '.dat' ); | |
63 | print $tmp "Some data\n"; | |
64 | print "Filename is $tmp\n"; | |
65 | ||
66 | ||
262eb13a GS |
67 | MkTemp family: |
68 | ||
69 | use File::Temp qw/ :mktemp /; | |
70 | ||
71 | ($fh, $file) = mkstemp( "tmpfileXXXXX" ); | |
72 | ($fh, $file) = mkstemps( "tmpfileXXXXXX", $suffix); | |
73 | ||
74 | $tmpdir = mkdtemp( $template ); | |
75 | ||
76 | $unopened_file = mktemp( $template ); | |
77 | ||
78 | POSIX functions: | |
79 | ||
80 | use File::Temp qw/ :POSIX /; | |
81 | ||
82 | $file = tmpnam(); | |
83 | $fh = tmpfile(); | |
84 | ||
85 | ($fh, $file) = tmpnam(); | |
c6d63c67 | 86 | $fh = tmpfile(); |
262eb13a GS |
87 | |
88 | ||
89 | Compatibility functions: | |
90 | ||
91 | $unopened_file = File::Temp::tempnam( $dir, $pfx ); | |
92 | ||
262eb13a GS |
93 | =head1 DESCRIPTION |
94 | ||
4a094b80 JH |
95 | C<File::Temp> can be used to create and open temporary files in a safe |
96 | way. There is both a function interface and an object-oriented | |
97 | interface. The File::Temp constructor or the tempfile() function can | |
98 | be used to return the name and the open filehandle of a temporary | |
99 | file. The tempdir() function can be used to create a temporary | |
100 | directory. | |
262eb13a GS |
101 | |
102 | The security aspect of temporary file creation is emphasized such that | |
781948c1 JH |
103 | a filehandle and filename are returned together. This helps guarantee |
104 | that a race condition can not occur where the temporary file is | |
105 | created by another process between checking for the existence of the | |
106 | file and its opening. Additional security levels are provided to | |
107 | check, for example, that the sticky bit is set on world writable | |
108 | directories. See L<"safe_level"> for more information. | |
262eb13a GS |
109 | |
110 | For compatibility with popular C library functions, Perl implementations of | |
111 | the mkstemp() family of functions are provided. These are, mkstemp(), | |
112 | mkstemps(), mkdtemp() and mktemp(). | |
113 | ||
114 | Additionally, implementations of the standard L<POSIX|POSIX> | |
115 | tmpnam() and tmpfile() functions are provided if required. | |
116 | ||
117 | Implementations of mktemp(), tmpnam(), and tempnam() are provided, | |
118 | but should be used with caution since they return only a filename | |
119 | that was valid when function was called, so cannot guarantee | |
120 | that the file will not exist by the time the caller opens the filename. | |
121 | ||
122 | =cut | |
123 | ||
124 | # 5.6.0 gives us S_IWOTH, S_IWGRP, our and auto-vivifying filehandls | |
125 | # People would like a version on 5.005 so give them what they want :-) | |
126 | use 5.005; | |
127 | use strict; | |
128 | use Carp; | |
129 | use File::Spec 0.8; | |
130 | use File::Path qw/ rmtree /; | |
131 | use Fcntl 1.03; | |
11d7f64f | 132 | use Errno; |
51fc852f | 133 | require VMS::Stdio if $^O eq 'VMS'; |
262eb13a | 134 | |
51fc852f | 135 | # Need the Symbol package if we are running older perl |
1c19c868 JH |
136 | require Symbol if $] < 5.006; |
137 | ||
4a094b80 JH |
138 | ### For the OO interface |
139 | use base qw/ IO::Handle /; | |
140 | use overload '""' => "STRINGIFY"; | |
141 | ||
1c19c868 | 142 | |
262eb13a GS |
143 | # use 'our' on v5.6.0 |
144 | use vars qw($VERSION @EXPORT_OK %EXPORT_TAGS $DEBUG); | |
145 | ||
146 | $DEBUG = 0; | |
147 | ||
148 | # We are exporting functions | |
149 | ||
262eb13a GS |
150 | use base qw/Exporter/; |
151 | ||
152 | # Export list - to allow fine tuning of export table | |
153 | ||
154 | @EXPORT_OK = qw{ | |
155 | tempfile | |
156 | tempdir | |
157 | tmpnam | |
158 | tmpfile | |
159 | mktemp | |
669b450a | 160 | mkstemp |
262eb13a GS |
161 | mkstemps |
162 | mkdtemp | |
163 | unlink0 | |
164 | }; | |
165 | ||
166 | # Groups of functions for export | |
167 | ||
168 | %EXPORT_TAGS = ( | |
169 | 'POSIX' => [qw/ tmpnam tmpfile /], | |
170 | 'mktemp' => [qw/ mktemp mkstemp mkstemps mkdtemp/], | |
171 | ); | |
172 | ||
173 | # add contents of these tags to @EXPORT | |
174 | Exporter::export_tags('POSIX','mktemp'); | |
175 | ||
be708cc0 | 176 | # Version number |
262eb13a | 177 | |
0c52c6a9 | 178 | $VERSION = '0.14_01'; |
262eb13a GS |
179 | |
180 | # This is a list of characters that can be used in random filenames | |
181 | ||
182 | 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 | |
183 | 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 | |
669b450a | 184 | 0 1 2 3 4 5 6 7 8 9 _ |
262eb13a GS |
185 | /); |
186 | ||
187 | # Maximum number of tries to make a temp file before failing | |
188 | ||
189 | use constant MAX_TRIES => 10; | |
190 | ||
191 | # Minimum number of X characters that should be in a template | |
192 | use constant MINX => 4; | |
193 | ||
194 | # Default template when no template supplied | |
195 | ||
196 | use constant TEMPXXX => 'X' x 10; | |
197 | ||
198 | # Constants for the security level | |
199 | ||
200 | use constant STANDARD => 0; | |
201 | use constant MEDIUM => 1; | |
202 | use constant HIGH => 2; | |
203 | ||
1c19c868 JH |
204 | # OPENFLAGS. If we defined the flag to use with Sysopen here this gives |
205 | # us an optimisation when many temporary files are requested | |
206 | ||
207 | my $OPENFLAGS = O_CREAT | O_EXCL | O_RDWR; | |
208 | ||
be708cc0 JH |
209 | unless ($^O eq 'MacOS') { |
210 | for my $oflag (qw/ FOLLOW BINARY LARGEFILE EXLOCK NOINHERIT /) { | |
211 | my ($bit, $func) = (0, "Fcntl::O_" . $oflag); | |
212 | no strict 'refs'; | |
213 | $OPENFLAGS |= $bit if eval { | |
214 | # Make sure that redefined die handlers do not cause problems | |
215 | # eg CGI::Carp | |
216 | local $SIG{__DIE__} = sub {}; | |
217 | local $SIG{__WARN__} = sub {}; | |
218 | $bit = &$func(); | |
219 | 1; | |
220 | }; | |
221 | } | |
1c19c868 JH |
222 | } |
223 | ||
51fc852f TJ |
224 | # On some systems the O_TEMPORARY flag can be used to tell the OS |
225 | # to automatically remove the file when it is closed. This is fine | |
226 | # in most cases but not if tempfile is called with UNLINK=>0 and | |
227 | # the filename is requested -- in the case where the filename is to | |
228 | # be passed to another routine. This happens on windows. We overcome | |
229 | # this by using a second open flags variable | |
230 | ||
231 | my $OPENTEMPFLAGS = $OPENFLAGS; | |
be708cc0 JH |
232 | unless ($^O eq 'MacOS') { |
233 | for my $oflag (qw/ TEMPORARY /) { | |
234 | my ($bit, $func) = (0, "Fcntl::O_" . $oflag); | |
235 | no strict 'refs'; | |
236 | $OPENTEMPFLAGS |= $bit if eval { | |
237 | # Make sure that redefined die handlers do not cause problems | |
238 | # eg CGI::Carp | |
239 | local $SIG{__DIE__} = sub {}; | |
240 | local $SIG{__WARN__} = sub {}; | |
241 | $bit = &$func(); | |
242 | 1; | |
243 | }; | |
244 | } | |
51fc852f | 245 | } |
1c19c868 | 246 | |
262eb13a GS |
247 | # INTERNAL ROUTINES - not to be used outside of package |
248 | ||
249 | # Generic routine for getting a temporary filename | |
250 | # modelled on OpenBSD _gettemp() in mktemp.c | |
251 | ||
669b450a | 252 | # The template must contain X's that are to be replaced |
262eb13a GS |
253 | # with the random values |
254 | ||
255 | # Arguments: | |
256 | ||
257 | # TEMPLATE - string containing the XXXXX's that is converted | |
258 | # to a random filename and opened if required | |
259 | ||
260 | # Optionally, a hash can also be supplied containing specific options | |
261 | # "open" => if true open the temp file, else just return the name | |
262 | # default is 0 | |
263 | # "mkdir"=> if true, we are creating a temp directory rather than tempfile | |
264 | # default is 0 | |
265 | # "suffixlen" => number of characters at end of PATH to be ignored. | |
266 | # default is 0. | |
51fc852f TJ |
267 | # "unlink_on_close" => indicates that, if possible, the OS should remove |
268 | # the file as soon as it is closed. Usually indicates | |
be708cc0 | 269 | # use of the O_TEMPORARY flag to sysopen. |
51fc852f TJ |
270 | # Usually irrelevant on unix |
271 | ||
28d6a1e0 TJ |
272 | # Optionally a reference to a scalar can be passed into the function |
273 | # On error this will be used to store the reason for the error | |
274 | # "ErrStr" => \$errstr | |
0e939f40 | 275 | |
262eb13a | 276 | # "open" and "mkdir" can not both be true |
51fc852f | 277 | # "unlink_on_close" is not used when "mkdir" is true. |
262eb13a GS |
278 | |
279 | # The default options are equivalent to mktemp(). | |
280 | ||
281 | # Returns: | |
282 | # filehandle - open file handle (if called with doopen=1, else undef) | |
283 | # temp name - name of the temp file or directory | |
284 | ||
285 | # For example: | |
286 | # ($fh, $name) = _gettemp($template, "open" => 1); | |
287 | ||
288 | # for the current version, failures are associated with | |
28d6a1e0 TJ |
289 | # stored in an error string and returned to give the reason whilst debugging |
290 | # This routine is not called by any external function | |
262eb13a GS |
291 | sub _gettemp { |
292 | ||
293 | croak 'Usage: ($fh, $name) = _gettemp($template, OPTIONS);' | |
294 | unless scalar(@_) >= 1; | |
295 | ||
28d6a1e0 TJ |
296 | # the internal error string - expect it to be overridden |
297 | # Need this in case the caller decides not to supply us a value | |
298 | # need an anonymous scalar | |
299 | my $tempErrStr; | |
0e939f40 | 300 | |
262eb13a GS |
301 | # Default options |
302 | my %options = ( | |
303 | "open" => 0, | |
304 | "mkdir" => 0, | |
305 | "suffixlen" => 0, | |
51fc852f | 306 | "unlink_on_close" => 0, |
28d6a1e0 | 307 | "ErrStr" => \$tempErrStr, |
262eb13a GS |
308 | ); |
309 | ||
310 | # Read the template | |
311 | my $template = shift; | |
312 | if (ref($template)) { | |
28d6a1e0 | 313 | # Use a warning here since we have not yet merged ErrStr |
262eb13a GS |
314 | carp "File::Temp::_gettemp: template must not be a reference"; |
315 | return (); | |
316 | } | |
317 | ||
318 | # Check that the number of entries on stack are even | |
319 | if (scalar(@_) % 2 != 0) { | |
28d6a1e0 | 320 | # Use a warning here since we have not yet merged ErrStr |
262eb13a GS |
321 | carp "File::Temp::_gettemp: Must have even number of options"; |
322 | return (); | |
323 | } | |
324 | ||
325 | # Read the options and merge with defaults | |
326 | %options = (%options, @_) if @_; | |
669b450a | 327 | |
28d6a1e0 TJ |
328 | # Make sure the error string is set to undef |
329 | ${$options{ErrStr}} = undef; | |
0e939f40 | 330 | |
262eb13a GS |
331 | # Can not open the file and make a directory in a single call |
332 | if ($options{"open"} && $options{"mkdir"}) { | |
28d6a1e0 | 333 | ${$options{ErrStr}} = "doopen and domkdir can not both be true\n"; |
262eb13a GS |
334 | return (); |
335 | } | |
336 | ||
337 | # Find the start of the end of the Xs (position of last X) | |
338 | # Substr starts from 0 | |
339 | my $start = length($template) - 1 - $options{"suffixlen"}; | |
340 | ||
341 | # Check that we have at least MINX x X (eg 'XXXX") at the end of the string | |
342 | # (taking suffixlen into account). Any fewer is insecure. | |
343 | ||
344 | # Do it using substr - no reason to use a pattern match since | |
345 | # we know where we are looking and what we are looking for | |
346 | ||
347 | if (substr($template, $start - MINX + 1, MINX) ne 'X' x MINX) { | |
28d6a1e0 TJ |
348 | ${$options{ErrStr}} = "The template must contain at least ". |
349 | MINX . " 'X' characters\n"; | |
262eb13a GS |
350 | return (); |
351 | } | |
352 | ||
353 | # Replace all the X at the end of the substring with a | |
354 | # random character or just all the XX at the end of a full string. | |
355 | # Do it as an if, since the suffix adjusts which section to replace | |
356 | # and suffixlen=0 returns nothing if used in the substr directly | |
357 | # and generate a full path from the template | |
358 | ||
359 | my $path = _replace_XX($template, $options{"suffixlen"}); | |
360 | ||
361 | ||
362 | # Split the path into constituent parts - eventually we need to check | |
363 | # whether the directory exists | |
364 | # We need to know whether we are making a temp directory | |
365 | # or a tempfile | |
366 | ||
367 | my ($volume, $directories, $file); | |
368 | my $parent; # parent directory | |
369 | if ($options{"mkdir"}) { | |
370 | # There is no filename at the end | |
371 | ($volume, $directories, $file) = File::Spec->splitpath( $path, 1); | |
372 | ||
373 | # The parent is then $directories without the last directory | |
374 | # Split the directory and put it back together again | |
375 | my @dirs = File::Spec->splitdir($directories); | |
376 | ||
be708cc0 JH |
377 | # If @dirs only has one entry (i.e. the directory template) that means |
378 | # we are in the current directory | |
262eb13a GS |
379 | if ($#dirs == 0) { |
380 | $parent = File::Spec->curdir; | |
381 | } else { | |
382 | ||
669b450a JH |
383 | if ($^O eq 'VMS') { # need volume to avoid relative dir spec |
384 | $parent = File::Spec->catdir($volume, @dirs[0..$#dirs-1]); | |
e4dfc136 | 385 | $parent = 'sys$disk:[]' if $parent eq ''; |
669b450a JH |
386 | } else { |
387 | ||
388 | # Put it back together without the last one | |
389 | $parent = File::Spec->catdir(@dirs[0..$#dirs-1]); | |
262eb13a | 390 | |
669b450a JH |
391 | # ...and attach the volume (no filename) |
392 | $parent = File::Spec->catpath($volume, $parent, ''); | |
393 | } | |
262eb13a GS |
394 | |
395 | } | |
396 | ||
397 | } else { | |
398 | ||
399 | # Get rid of the last filename (use File::Basename for this?) | |
400 | ($volume, $directories, $file) = File::Spec->splitpath( $path ); | |
401 | ||
402 | # Join up without the file part | |
403 | $parent = File::Spec->catpath($volume,$directories,''); | |
404 | ||
405 | # If $parent is empty replace with curdir | |
406 | $parent = File::Spec->curdir | |
407 | unless $directories ne ''; | |
408 | ||
409 | } | |
410 | ||
be708cc0 | 411 | # Check that the parent directories exist |
262eb13a GS |
412 | # Do this even for the case where we are simply returning a name |
413 | # not a file -- no point returning a name that includes a directory | |
414 | # that does not exist or is not writable | |
415 | ||
28d6a1e0 TJ |
416 | unless (-d $parent) { |
417 | ${$options{ErrStr}} = "Parent directory ($parent) is not a directory"; | |
418 | return (); | |
419 | } | |
420 | unless (-w _) { | |
421 | ${$options{ErrStr}} = "Parent directory ($parent) is not writable\n"; | |
262eb13a GS |
422 | return (); |
423 | } | |
424 | ||
0e939f40 | 425 | |
262eb13a GS |
426 | # Check the stickiness of the directory and chown giveaway if required |
427 | # If the directory is world writable the sticky bit | |
428 | # must be set | |
429 | ||
430 | if (File::Temp->safe_level == MEDIUM) { | |
28d6a1e0 TJ |
431 | my $safeerr; |
432 | unless (_is_safe($parent,\$safeerr)) { | |
433 | ${$options{ErrStr}} = "Parent directory ($parent) is not safe ($safeerr)"; | |
262eb13a GS |
434 | return (); |
435 | } | |
436 | } elsif (File::Temp->safe_level == HIGH) { | |
28d6a1e0 TJ |
437 | my $safeerr; |
438 | unless (_is_verysafe($parent, \$safeerr)) { | |
439 | ${$options{ErrStr}} = "Parent directory ($parent) is not safe ($safeerr)"; | |
262eb13a GS |
440 | return (); |
441 | } | |
442 | } | |
443 | ||
444 | ||
262eb13a GS |
445 | # Now try MAX_TRIES time to open the file |
446 | for (my $i = 0; $i < MAX_TRIES; $i++) { | |
447 | ||
448 | # Try to open the file if requested | |
449 | if ($options{"open"}) { | |
450 | my $fh; | |
451 | ||
452 | # If we are running before perl5.6.0 we can not auto-vivify | |
453 | if ($] < 5.006) { | |
262eb13a GS |
454 | $fh = &Symbol::gensym; |
455 | } | |
456 | ||
457 | # Try to make sure this will be marked close-on-exec | |
458 | # XXX: Win32 doesn't respect this, nor the proper fcntl, | |
459 | # but may have O_NOINHERIT. This may or may not be in Fcntl. | |
28d6a1e0 | 460 | local $^F = 2; |
262eb13a GS |
461 | |
462 | # Store callers umask | |
97c10e77 | 463 | my $umask = umask(); |
262eb13a GS |
464 | |
465 | # Set a known umask | |
97c10e77 | 466 | umask(066); |
262eb13a GS |
467 | |
468 | # Attempt to open the file | |
51fc852f | 469 | my $open_success = undef; |
f826e675 JH |
470 | if ( $^O eq 'VMS' and $options{"unlink_on_close"} ) { |
471 | # make it auto delete on close by setting FAB$V_DLT bit | |
51fc852f TJ |
472 | $fh = VMS::Stdio::vmssysopen($path, $OPENFLAGS, 0600, 'fop=dlt'); |
473 | $open_success = $fh; | |
474 | } else { | |
475 | my $flags = ( $options{"unlink_on_close"} ? | |
476 | $OPENTEMPFLAGS : | |
477 | $OPENFLAGS ); | |
478 | $open_success = sysopen($fh, $path, $flags, 0600); | |
479 | } | |
480 | if ( $open_success ) { | |
262eb13a GS |
481 | |
482 | # Reset umask | |
d5201bd2 | 483 | umask($umask) if defined $umask; |
be708cc0 | 484 | |
262eb13a GS |
485 | # Opened successfully - return file handle and name |
486 | return ($fh, $path); | |
487 | ||
488 | } else { | |
489 | # Reset umask | |
d5201bd2 | 490 | umask($umask) if defined $umask; |
262eb13a GS |
491 | |
492 | # Error opening file - abort with error | |
493 | # if the reason was anything but EEXIST | |
11d7f64f | 494 | unless ($!{EEXIST}) { |
28d6a1e0 | 495 | ${$options{ErrStr}} = "Could not create temp file $path: $!"; |
262eb13a GS |
496 | return (); |
497 | } | |
498 | ||
499 | # Loop round for another try | |
be708cc0 | 500 | |
262eb13a GS |
501 | } |
502 | } elsif ($options{"mkdir"}) { | |
503 | ||
504 | # Store callers umask | |
97c10e77 | 505 | my $umask = umask(); |
262eb13a GS |
506 | |
507 | # Set a known umask | |
97c10e77 | 508 | umask(066); |
262eb13a GS |
509 | |
510 | # Open the temp directory | |
511 | if (mkdir( $path, 0700)) { | |
512 | # created okay | |
513 | # Reset umask | |
d5201bd2 | 514 | umask($umask) if defined $umask; |
262eb13a GS |
515 | |
516 | return undef, $path; | |
517 | } else { | |
518 | ||
519 | # Reset umask | |
d5201bd2 | 520 | umask($umask) if defined $umask; |
262eb13a GS |
521 | |
522 | # Abort with error if the reason for failure was anything | |
523 | # except EEXIST | |
11d7f64f | 524 | unless ($!{EEXIST}) { |
28d6a1e0 | 525 | ${$options{ErrStr}} = "Could not create directory $path: $!"; |
262eb13a GS |
526 | return (); |
527 | } | |
528 | ||
529 | # Loop round for another try | |
530 | ||
531 | } | |
532 | ||
533 | } else { | |
534 | ||
535 | # Return true if the file can not be found | |
536 | # Directory has been checked previously | |
537 | ||
538 | return (undef, $path) unless -e $path; | |
539 | ||
669b450a | 540 | # Try again until MAX_TRIES |
262eb13a GS |
541 | |
542 | } | |
669b450a | 543 | |
262eb13a GS |
544 | # Did not successfully open the tempfile/dir |
545 | # so try again with a different set of random letters | |
546 | # No point in trying to increment unless we have only | |
547 | # 1 X say and the randomness could come up with the same | |
548 | # file MAX_TRIES in a row. | |
549 | ||
550 | # Store current attempt - in principal this implies that the | |
551 | # 3rd time around the open attempt that the first temp file | |
552 | # name could be generated again. Probably should store each | |
553 | # attempt and make sure that none are repeated | |
554 | ||
555 | my $original = $path; | |
556 | my $counter = 0; # Stop infinite loop | |
557 | my $MAX_GUESS = 50; | |
558 | ||
559 | do { | |
560 | ||
561 | # Generate new name from original template | |
562 | $path = _replace_XX($template, $options{"suffixlen"}); | |
563 | ||
564 | $counter++; | |
565 | ||
566 | } until ($path ne $original || $counter > $MAX_GUESS); | |
567 | ||
568 | # Check for out of control looping | |
569 | if ($counter > $MAX_GUESS) { | |
28d6a1e0 | 570 | ${$options{ErrStr}} = "Tried to get a new temp name different to the previous value $MAX_GUESS times.\nSomething wrong with template?? ($template)"; |
262eb13a GS |
571 | return (); |
572 | } | |
573 | ||
574 | } | |
575 | ||
576 | # If we get here, we have run out of tries | |
28d6a1e0 TJ |
577 | ${ $options{ErrStr} } = "Have exceeded the maximum number of attempts (" |
578 | . MAX_TRIES . ") to open temp file/dir"; | |
262eb13a GS |
579 | |
580 | return (); | |
581 | ||
582 | } | |
583 | ||
584 | # Internal routine to return a random character from the | |
585 | # character list. Does not do an srand() since rand() | |
586 | # will do one automatically | |
587 | ||
588 | # No arguments. Return value is the random character | |
589 | ||
1c19c868 JH |
590 | # No longer called since _replace_XX runs a few percent faster if |
591 | # I inline the code. This is important if we are creating thousands of | |
592 | # temporary files. | |
593 | ||
262eb13a GS |
594 | sub _randchar { |
595 | ||
596 | $CHARS[ int( rand( $#CHARS ) ) ]; | |
597 | ||
598 | } | |
599 | ||
600 | # Internal routine to replace the XXXX... with random characters | |
be708cc0 | 601 | # This has to be done by _gettemp() every time it fails to |
262eb13a GS |
602 | # open a temp file/dir |
603 | ||
be708cc0 | 604 | # Arguments: $template (the template with XXX), |
262eb13a GS |
605 | # $ignore (number of characters at end to ignore) |
606 | ||
607 | # Returns: modified template | |
608 | ||
609 | sub _replace_XX { | |
610 | ||
611 | croak 'Usage: _replace_XX($template, $ignore)' | |
612 | unless scalar(@_) == 2; | |
613 | ||
614 | my ($path, $ignore) = @_; | |
615 | ||
616 | # Do it as an if, since the suffix adjusts which section to replace | |
617 | # and suffixlen=0 returns nothing if used in the substr directly | |
618 | # Alternatively, could simply set $ignore to length($path)-1 | |
619 | # Don't want to always use substr when not required though. | |
620 | ||
621 | if ($ignore) { | |
1c19c868 | 622 | substr($path, 0, - $ignore) =~ s/X(?=X*\z)/$CHARS[ int( rand( $#CHARS ) ) ]/ge; |
262eb13a | 623 | } else { |
1c19c868 | 624 | $path =~ s/X(?=X*\z)/$CHARS[ int( rand( $#CHARS ) ) ]/ge; |
262eb13a GS |
625 | } |
626 | ||
627 | return $path; | |
628 | } | |
629 | ||
630 | # internal routine to check to see if the directory is safe | |
669b450a | 631 | # First checks to see if the directory is not owned by the |
262eb13a | 632 | # current user or root. Then checks to see if anyone else |
669b450a | 633 | # can write to the directory and if so, checks to see if |
262eb13a GS |
634 | # it has the sticky bit set |
635 | ||
636 | # Will not work on systems that do not support sticky bit | |
637 | ||
638 | #Args: directory path to check | |
28d6a1e0 | 639 | # Optionally: reference to scalar to contain error message |
262eb13a GS |
640 | # Returns true if the path is safe and false otherwise. |
641 | # Returns undef if can not even run stat() on the path | |
642 | ||
643 | # This routine based on version written by Tom Christiansen | |
644 | ||
645 | # Presumably, by the time we actually attempt to create the | |
646 | # file or directory in this directory, it may not be safe | |
647 | # anymore... Have to run _is_safe directly after the open. | |
648 | ||
649 | sub _is_safe { | |
650 | ||
651 | my $path = shift; | |
28d6a1e0 | 652 | my $err_ref = shift; |
262eb13a GS |
653 | |
654 | # Stat path | |
655 | my @info = stat($path); | |
28d6a1e0 TJ |
656 | unless (scalar(@info)) { |
657 | $$err_ref = "stat(path) returned no values"; | |
658 | return 0; | |
659 | }; | |
669b450a | 660 | return 1 if $^O eq 'VMS'; # owner delete control at file level |
262eb13a GS |
661 | |
662 | # Check to see whether owner is neither superuser (or a system uid) nor me | |
663 | # Use the real uid from the $< variable | |
664 | # UID is in [4] | |
73f754d1 A |
665 | if ($info[4] > File::Temp->top_system_uid() && $info[4] != $<) { |
666 | ||
667 | Carp::cluck(sprintf "uid=$info[4] topuid=%s \$<=$< path='$path'", | |
668 | File::Temp->top_system_uid()); | |
669 | ||
28d6a1e0 TJ |
670 | $$err_ref = "Directory owned neither by root nor the current user" |
671 | if ref($err_ref); | |
262eb13a GS |
672 | return 0; |
673 | } | |
674 | ||
675 | # check whether group or other can write file | |
676 | # use 066 to detect either reading or writing | |
677 | # use 022 to check writability | |
678 | # Do it with S_IWOTH and S_IWGRP for portability (maybe) | |
679 | # mode is in info[2] | |
680 | if (($info[2] & &Fcntl::S_IWGRP) || # Is group writable? | |
681 | ($info[2] & &Fcntl::S_IWOTH) ) { # Is world writable? | |
28d6a1e0 TJ |
682 | # Must be a directory |
683 | unless (-d _) { | |
684 | $$err_ref = "Path ($path) is not a directory" | |
685 | if ref($err_ref); | |
686 | return 0; | |
687 | } | |
688 | # Must have sticky bit set | |
689 | unless (-k _) { | |
690 | $$err_ref = "Sticky bit not set on $path when dir is group|world writable" | |
691 | if ref($err_ref); | |
692 | return 0; | |
693 | } | |
262eb13a GS |
694 | } |
695 | ||
696 | return 1; | |
697 | } | |
698 | ||
699 | # Internal routine to check whether a directory is safe | |
be708cc0 | 700 | # for temp files. Safer than _is_safe since it checks for |
262eb13a GS |
701 | # the possibility of chown giveaway and if that is a possibility |
702 | # checks each directory in the path to see if it is safe (with _is_safe) | |
703 | ||
704 | # If _PC_CHOWN_RESTRICTED is not set, does the full test of each | |
705 | # directory anyway. | |
706 | ||
28d6a1e0 | 707 | # Takes optional second arg as scalar ref to error reason |
0e939f40 | 708 | |
262eb13a GS |
709 | sub _is_verysafe { |
710 | ||
711 | # Need POSIX - but only want to bother if really necessary due to overhead | |
712 | require POSIX; | |
713 | ||
714 | my $path = shift; | |
28d6a1e0 | 715 | print "_is_verysafe testing $path\n" if $DEBUG; |
669b450a | 716 | return 1 if $^O eq 'VMS'; # owner delete control at file level |
262eb13a | 717 | |
28d6a1e0 | 718 | my $err_ref = shift; |
0e939f40 | 719 | |
262eb13a GS |
720 | # Should Get the value of _PC_CHOWN_RESTRICTED if it is defined |
721 | # and If it is not there do the extensive test | |
722 | my $chown_restricted; | |
723 | $chown_restricted = &POSIX::_PC_CHOWN_RESTRICTED() | |
724 | if eval { &POSIX::_PC_CHOWN_RESTRICTED(); 1}; | |
725 | ||
726 | # If chown_resticted is set to some value we should test it | |
727 | if (defined $chown_restricted) { | |
728 | ||
729 | # Return if the current directory is safe | |
28d6a1e0 | 730 | return _is_safe($path,$err_ref) if POSIX::sysconf( $chown_restricted ); |
262eb13a GS |
731 | |
732 | } | |
733 | ||
734 | # To reach this point either, the _PC_CHOWN_RESTRICTED symbol | |
735 | # was not avialable or the symbol was there but chown giveaway | |
736 | # is allowed. Either way, we now have to test the entire tree for | |
737 | # safety. | |
738 | ||
739 | # Convert path to an absolute directory if required | |
740 | unless (File::Spec->file_name_is_absolute($path)) { | |
741 | $path = File::Spec->rel2abs($path); | |
742 | } | |
743 | ||
744 | # Split directory into components - assume no file | |
745 | my ($volume, $directories, undef) = File::Spec->splitpath( $path, 1); | |
746 | ||
d1be9408 | 747 | # Slightly less efficient than having a function in File::Spec |
262eb13a GS |
748 | # to chop off the end of a directory or even a function that |
749 | # can handle ../ in a directory tree | |
750 | # Sometimes splitdir() returns a blank at the end | |
751 | # so we will probably check the bottom directory twice in some cases | |
752 | my @dirs = File::Spec->splitdir($directories); | |
753 | ||
754 | # Concatenate one less directory each time around | |
755 | foreach my $pos (0.. $#dirs) { | |
756 | # Get a directory name | |
757 | my $dir = File::Spec->catpath($volume, | |
758 | File::Spec->catdir(@dirs[0.. $#dirs - $pos]), | |
759 | '' | |
760 | ); | |
761 | ||
762 | print "TESTING DIR $dir\n" if $DEBUG; | |
763 | ||
764 | # Check the directory | |
28d6a1e0 | 765 | return 0 unless _is_safe($dir,$err_ref); |
262eb13a GS |
766 | |
767 | } | |
768 | ||
769 | return 1; | |
770 | } | |
771 | ||
772 | ||
773 | ||
774 | # internal routine to determine whether unlink works on this | |
775 | # platform for files that are currently open. | |
776 | # Returns true if we can, false otherwise. | |
777 | ||
669b450a JH |
778 | # Currently WinNT, OS/2 and VMS can not unlink an opened file |
779 | # On VMS this is because the O_EXCL flag is used to open the | |
780 | # temporary file. Currently I do not know enough about the issues | |
781 | # on VMS to decide whether O_EXCL is a requirement. | |
262eb13a GS |
782 | |
783 | sub _can_unlink_opened_file { | |
784 | ||
be708cc0 | 785 | if ($^O eq 'MSWin32' || $^O eq 'os2' || $^O eq 'VMS' || $^O eq 'dos' || $^O eq 'MacOS') { |
1c19c868 JH |
786 | return 0; |
787 | } else { | |
788 | return 1; | |
789 | } | |
262eb13a GS |
790 | |
791 | } | |
792 | ||
1c19c868 JH |
793 | # internal routine to decide which security levels are allowed |
794 | # see safe_level() for more information on this | |
795 | ||
796 | # Controls whether the supplied security level is allowed | |
797 | ||
798 | # $cando = _can_do_level( $level ) | |
799 | ||
800 | sub _can_do_level { | |
801 | ||
802 | # Get security level | |
803 | my $level = shift; | |
804 | ||
805 | # Always have to be able to do STANDARD | |
806 | return 1 if $level == STANDARD; | |
807 | ||
808 | # Currently, the systems that can do HIGH or MEDIUM are identical | |
4a094b80 | 809 | if ( $^O eq 'MSWin32' || $^O eq 'os2' || $^O eq 'cygwin' || $^O eq 'dos' || $^O eq 'MacOS' || $^O eq 'mpeix') { |
1c19c868 JH |
810 | return 0; |
811 | } else { | |
812 | return 1; | |
813 | } | |
814 | ||
815 | } | |
262eb13a GS |
816 | |
817 | # This routine sets up a deferred unlinking of a specified | |
818 | # filename and filehandle. It is used in the following cases: | |
669b450a | 819 | # - Called by unlink0 if an opened file can not be unlinked |
262eb13a GS |
820 | # - Called by tempfile() if files are to be removed on shutdown |
821 | # - Called by tempdir() if directories are to be removed on shutdown | |
822 | ||
823 | # Arguments: | |
824 | # _deferred_unlink( $fh, $fname, $isdir ); | |
825 | # | |
826 | # - filehandle (so that it can be expclicitly closed if open | |
827 | # - filename (the thing we want to remove) | |
828 | # - isdir (flag to indicate that we are being given a directory) | |
829 | # [and hence no filehandle] | |
830 | ||
51fc852f | 831 | # Status is not referred to since all the magic is done with an END block |
262eb13a | 832 | |
1c19c868 JH |
833 | { |
834 | # Will set up two lexical variables to contain all the files to be | |
835 | # removed. One array for files, another for directories | |
836 | # They will only exist in this block | |
837 | # This means we only have to set up a single END block to remove all files | |
838 | # @files_to_unlink contains an array ref with the filehandle and filename | |
839 | my (@files_to_unlink, @dirs_to_unlink); | |
840 | ||
841 | # Set up an end block to use these arrays | |
842 | END { | |
843 | # Files | |
844 | foreach my $file (@files_to_unlink) { | |
845 | # close the filehandle without checking its state | |
846 | # in order to make real sure that this is closed | |
847 | # if its already closed then I dont care about the answer | |
848 | # probably a better way to do this | |
849 | close($file->[0]); # file handle is [0] | |
850 | ||
851 | if (-f $file->[1]) { # file name is [1] | |
852 | unlink $file->[1] or warn "Error removing ".$file->[1]; | |
853 | } | |
854 | } | |
855 | # Dirs | |
856 | foreach my $dir (@dirs_to_unlink) { | |
857 | if (-d $dir) { | |
6bfdb090 | 858 | rmtree($dir, $DEBUG, 0); |
1c19c868 JH |
859 | } |
860 | } | |
262eb13a | 861 | |
1c19c868 | 862 | } |
262eb13a | 863 | |
1c19c868 JH |
864 | # This is the sub called to register a file for deferred unlinking |
865 | # This could simply store the input parameters and defer everything | |
866 | # until the END block. For now we do a bit of checking at this | |
867 | # point in order to make sure that (1) we have a file/dir to delete | |
868 | # and (2) we have been called with the correct arguments. | |
869 | sub _deferred_unlink { | |
870 | ||
871 | croak 'Usage: _deferred_unlink($fh, $fname, $isdir)' | |
872 | unless scalar(@_) == 3; | |
669b450a | 873 | |
1c19c868 | 874 | my ($fh, $fname, $isdir) = @_; |
262eb13a | 875 | |
1c19c868 JH |
876 | warn "Setting up deferred removal of $fname\n" |
877 | if $DEBUG; | |
669b450a | 878 | |
1c19c868 JH |
879 | # If we have a directory, check that it is a directory |
880 | if ($isdir) { | |
262eb13a | 881 | |
1c19c868 | 882 | if (-d $fname) { |
262eb13a | 883 | |
1c19c868 | 884 | # Directory exists so store it |
51fc852f TJ |
885 | # first on VMS turn []foo into [.foo] for rmtree |
886 | $fname = VMS::Filespec::vmspath($fname) if $^O eq 'VMS'; | |
1c19c868 | 887 | push (@dirs_to_unlink, $fname); |
262eb13a | 888 | |
1c19c868 | 889 | } else { |
28d6a1e0 | 890 | carp "Request to remove directory $fname could not be completed since it does not exist!\n" if $^W; |
1c19c868 JH |
891 | } |
892 | ||
262eb13a | 893 | } else { |
262eb13a | 894 | |
1c19c868 | 895 | if (-f $fname) { |
262eb13a | 896 | |
1c19c868 JH |
897 | # file exists so store handle and name for later removal |
898 | push(@files_to_unlink, [$fh, $fname]); | |
262eb13a | 899 | |
1c19c868 | 900 | } else { |
28d6a1e0 | 901 | carp "Request to remove file $fname could not be completed since it is not there!\n" if $^W; |
1c19c868 | 902 | } |
262eb13a | 903 | |
262eb13a GS |
904 | } |
905 | ||
262eb13a GS |
906 | } |
907 | ||
262eb13a | 908 | |
1c19c868 | 909 | } |
262eb13a | 910 | |
4a094b80 JH |
911 | =head1 OO INTERFACE |
912 | ||
913 | This is the primary interface for interacting with | |
914 | C<File::Temp>. Using the OO interface a temporary file can be created | |
915 | when the object is constructed and the file can be removed when the | |
916 | object is no longer required. | |
917 | ||
918 | Note that there is no method to obtain the filehandle from the | |
919 | C<File::Temp> object. The object itself acts as a filehandle. Also, | |
920 | the object is configured such that it stringifies to the name of the | |
921 | temporary file. | |
922 | ||
923 | =over 4 | |
924 | ||
925 | =item B<new> | |
926 | ||
927 | Create a temporary file object. | |
928 | ||
929 | my $tmp = new File::Temp(); | |
930 | ||
931 | by default the object is constructed as if C<tempfile> | |
932 | was called without options, but with the additional behaviour | |
933 | that the temporary file is removed by the object destructor | |
934 | if UNLINK is set to true (the default). | |
935 | ||
936 | Supported arguments are the same as for C<tempfile>: UNLINK | |
937 | (defaulting to true), DIR and SUFFIX. Additionally, the filename | |
938 | template is specified using the TEMPLATE option. The OPEN option | |
939 | is not supported (the file is always opened). | |
940 | ||
941 | $tmp = new File::Temp( TEMPLATE => 'tempXXXXX', | |
942 | DIR => 'mydir', | |
943 | SUFFIX => '.dat'); | |
944 | ||
945 | Arguments are case insensitive. | |
946 | ||
947 | =cut | |
948 | ||
949 | sub new { | |
950 | my $proto = shift; | |
951 | my $class = ref($proto) || $proto; | |
952 | ||
953 | # read arguments and convert keys to upper case | |
954 | my %args = @_; | |
955 | %args = map { uc($_), $args{$_} } keys %args; | |
956 | ||
957 | # see if they are unlinking (defaulting to yes) | |
958 | my $unlink = (exists $args{UNLINK} ? $args{UNLINK} : 1 ); | |
959 | delete $args{UNLINK}; | |
960 | ||
961 | # template (store it in an error so that it will | |
962 | # disappear from the arg list of tempfile | |
963 | my @template = ( exists $args{TEMPLATE} ? $args{TEMPLATE} : () ); | |
964 | delete $args{TEMPLATE}; | |
965 | ||
966 | # Protect OPEN | |
967 | delete $args{OPEN}; | |
968 | ||
969 | # Open the file and retain file handle and file name | |
970 | my ($fh, $path) = tempfile( @template, %args ); | |
971 | ||
972 | print "Tmp: $fh - $path\n" if $DEBUG; | |
973 | ||
974 | # Store the filename in the scalar slot | |
975 | ${*$fh} = $path; | |
976 | ||
977 | # Store unlink information in hash slot (plus other constructor info) | |
978 | %{*$fh} = %args; | |
979 | ${*$fh}{UNLINK} = $unlink; | |
980 | ||
981 | bless $fh, $class; | |
982 | ||
983 | return $fh; | |
984 | } | |
985 | ||
986 | =item B<filename> | |
987 | ||
988 | Return the name of the temporary file associated with this object. | |
989 | ||
990 | $filename = $tmp->filename; | |
991 | ||
992 | This method is called automatically when the object is used as | |
993 | a string. | |
994 | ||
995 | =cut | |
996 | ||
997 | sub filename { | |
998 | my $self = shift; | |
999 | return ${*$self}; | |
1000 | } | |
1001 | ||
1002 | sub STRINGIFY { | |
1003 | my $self = shift; | |
1004 | return $self->filename; | |
1005 | } | |
1006 | ||
1007 | =item B<DESTROY> | |
1008 | ||
1009 | When the object goes out of scope, the destructor is called. This | |
1010 | destructor will attempt to unlink the file (using C<unlink1>) | |
1011 | if the constructor was called with UNLINK set to 1 (the default state | |
1012 | if UNLINK is not specified). | |
1013 | ||
1014 | No error is given if the unlink fails. | |
1015 | ||
1016 | =cut | |
1017 | ||
1018 | sub DESTROY { | |
1019 | my $self = shift; | |
1020 | if (${*$self}{UNLINK}) { | |
1021 | print "# ---------> Unlinking $self\n" if $DEBUG; | |
1022 | ||
1023 | # The unlink1 may fail if the file has been closed | |
1024 | # by the caller. This leaves us with the decision | |
1025 | # of whether to refuse to remove the file or simply | |
1026 | # do an unlink without test. Seems to be silly | |
1027 | # to do this when we are trying to be careful | |
1028 | # about security | |
1029 | unlink1( $self, $self->filename ) | |
1030 | or unlink($self->filename); | |
1031 | } | |
1032 | } | |
1033 | ||
1034 | =back | |
1035 | ||
262eb13a GS |
1036 | =head1 FUNCTIONS |
1037 | ||
1038 | This section describes the recommended interface for generating | |
1039 | temporary files and directories. | |
1040 | ||
1041 | =over 4 | |
1042 | ||
1043 | =item B<tempfile> | |
1044 | ||
1045 | This is the basic function to generate temporary files. | |
1046 | The behaviour of the file can be changed using various options: | |
1047 | ||
1048 | ($fh, $filename) = tempfile(); | |
1049 | ||
1050 | Create a temporary file in the directory specified for temporary | |
1051 | files, as specified by the tmpdir() function in L<File::Spec>. | |
1052 | ||
1053 | ($fh, $filename) = tempfile($template); | |
1054 | ||
1055 | Create a temporary file in the current directory using the supplied | |
1056 | template. Trailing `X' characters are replaced with random letters to | |
1057 | generate the filename. At least four `X' characters must be present | |
4a094b80 | 1058 | at the end of the template. |
262eb13a GS |
1059 | |
1060 | ($fh, $filename) = tempfile($template, SUFFIX => $suffix) | |
1061 | ||
1062 | Same as previously, except that a suffix is added to the template | |
1063 | after the `X' translation. Useful for ensuring that a temporary | |
1064 | filename has a particular extension when needed by other applications. | |
1065 | But see the WARNING at the end. | |
1066 | ||
1067 | ($fh, $filename) = tempfile($template, DIR => $dir); | |
1068 | ||
1069 | Translates the template as before except that a directory name | |
1070 | is specified. | |
1071 | ||
51fc852f TJ |
1072 | ($fh, $filename) = tempfile($template, UNLINK => 1); |
1073 | ||
1074 | Return the filename and filehandle as before except that the file is | |
1075 | automatically removed when the program exits. Default is for the file | |
1076 | to be removed if a file handle is requested and to be kept if the | |
be708cc0 | 1077 | filename is requested. In a scalar context (where no filename is |
09d7a2f9 | 1078 | returned) the file is always deleted either on exit or when it is closed. |
51fc852f | 1079 | |
262eb13a GS |
1080 | If the template is not specified, a template is always |
1081 | automatically generated. This temporary file is placed in tmpdir() | |
be708cc0 | 1082 | (L<File::Spec>) unless a directory is specified explicitly with the |
262eb13a GS |
1083 | DIR option. |
1084 | ||
1085 | $fh = tempfile( $template, DIR => $dir ); | |
1086 | ||
1087 | If called in scalar context, only the filehandle is returned | |
be708cc0 | 1088 | and the file will automatically be deleted when closed (see |
262eb13a | 1089 | the description of tmpfile() elsewhere in this document). |
be708cc0 | 1090 | This is the preferred mode of operation, as if you only |
262eb13a GS |
1091 | have a filehandle, you can never create a race condition |
1092 | by fumbling with the filename. On systems that can not unlink | |
09d7a2f9 | 1093 | an open file or can not mark a file as temporary when it is opened |
4a094b80 | 1094 | (for example, Windows NT uses the C<O_TEMPORARY> flag) |
09d7a2f9 TJ |
1095 | the file is marked for deletion when the program ends (equivalent |
1096 | to setting UNLINK to 1). The C<UNLINK> flag is ignored if present. | |
1097 | ||
262eb13a GS |
1098 | (undef, $filename) = tempfile($template, OPEN => 0); |
1099 | ||
1100 | This will return the filename based on the template but | |
1101 | will not open this file. Cannot be used in conjunction with | |
be708cc0 | 1102 | UNLINK set to true. Default is to always open the file |
262eb13a GS |
1103 | to protect from possible race conditions. A warning is issued |
1104 | if warnings are turned on. Consider using the tmpnam() | |
1105 | and mktemp() functions described elsewhere in this document | |
1106 | if opening the file is not required. | |
1107 | ||
51fc852f TJ |
1108 | Options can be combined as required. |
1109 | ||
262eb13a GS |
1110 | =cut |
1111 | ||
1112 | sub tempfile { | |
1113 | ||
1114 | # Can not check for argument count since we can have any | |
1115 | # number of args | |
1116 | ||
1117 | # Default options | |
1118 | my %options = ( | |
1119 | "DIR" => undef, # Directory prefix | |
f826e675 JH |
1120 | "SUFFIX" => '', # Template suffix |
1121 | "UNLINK" => 0, # Do not unlink file on exit | |
1122 | "OPEN" => 1, # Open file | |
262eb13a GS |
1123 | ); |
1124 | ||
1125 | # Check to see whether we have an odd or even number of arguments | |
1126 | my $template = (scalar(@_) % 2 == 1 ? shift(@_) : undef); | |
1127 | ||
1128 | # Read the options and merge with defaults | |
1129 | %options = (%options, @_) if @_; | |
1130 | ||
1131 | # First decision is whether or not to open the file | |
1132 | if (! $options{"OPEN"}) { | |
1133 | ||
1134 | warn "tempfile(): temporary filename requested but not opened.\nPossibly unsafe, consider using tempfile() with OPEN set to true\n" | |
1135 | if $^W; | |
1136 | ||
1137 | } | |
1138 | ||
f826e675 JH |
1139 | if ($options{"DIR"} and $^O eq 'VMS') { |
1140 | ||
1141 | # on VMS turn []foo into [.foo] for concatenation | |
1142 | $options{"DIR"} = VMS::Filespec::vmspath($options{"DIR"}); | |
1143 | } | |
1144 | ||
669b450a | 1145 | # Construct the template |
262eb13a GS |
1146 | |
1147 | # Have a choice of trying to work around the mkstemp/mktemp/tmpnam etc | |
1148 | # functions or simply constructing a template and using _gettemp() | |
1149 | # explicitly. Go for the latter | |
1150 | ||
1151 | # First generate a template if not defined and prefix the directory | |
1152 | # If no template must prefix the temp directory | |
1153 | if (defined $template) { | |
1154 | if ($options{"DIR"}) { | |
1155 | ||
1156 | $template = File::Spec->catfile($options{"DIR"}, $template); | |
1157 | ||
1158 | } | |
1159 | ||
1160 | } else { | |
1161 | ||
1162 | if ($options{"DIR"}) { | |
1163 | ||
1164 | $template = File::Spec->catfile($options{"DIR"}, TEMPXXX); | |
1165 | ||
1166 | } else { | |
669b450a | 1167 | |
262eb13a GS |
1168 | $template = File::Spec->catfile(File::Spec->tmpdir, TEMPXXX); |
1169 | ||
1170 | } | |
669b450a | 1171 | |
262eb13a GS |
1172 | } |
1173 | ||
1174 | # Now add a suffix | |
1175 | $template .= $options{"SUFFIX"}; | |
1176 | ||
09d7a2f9 TJ |
1177 | # Determine whether we should tell _gettemp to unlink the file |
1178 | # On unix this is irrelevant and can be worked out after the file is | |
1179 | # opened (simply by unlinking the open filehandle). On Windows or VMS | |
1180 | # we have to indicate temporary-ness when we open the file. In general | |
be708cc0 | 1181 | # we only want a true temporary file if we are returning just the |
09d7a2f9 TJ |
1182 | # filehandle - if the user wants the filename they probably do not |
1183 | # want the file to disappear as soon as they close it. | |
1184 | # For this reason, tie unlink_on_close to the return context regardless | |
1185 | # of OS. | |
1186 | my $unlink_on_close = ( wantarray ? 0 : 1); | |
1187 | ||
262eb13a | 1188 | # Create the file |
28d6a1e0 TJ |
1189 | my ($fh, $path, $errstr); |
1190 | croak "Error in tempfile() using $template: $errstr" | |
262eb13a | 1191 | unless (($fh, $path) = _gettemp($template, |
51fc852f | 1192 | "open" => $options{'OPEN'}, |
262eb13a | 1193 | "mkdir"=> 0 , |
09d7a2f9 | 1194 | "unlink_on_close" => $unlink_on_close, |
262eb13a | 1195 | "suffixlen" => length($options{'SUFFIX'}), |
28d6a1e0 | 1196 | "ErrStr" => \$errstr, |
669b450a | 1197 | ) ); |
262eb13a GS |
1198 | |
1199 | # Set up an exit handler that can do whatever is right for the | |
09d7a2f9 TJ |
1200 | # system. This removes files at exit when requested explicitly or when |
1201 | # system is asked to unlink_on_close but is unable to do so because | |
1202 | # of OS limitations. | |
1203 | # The latter should be achieved by using a tied filehandle. | |
1204 | # Do not check return status since this is all done with END blocks. | |
262eb13a | 1205 | _deferred_unlink($fh, $path, 0) if $options{"UNLINK"}; |
669b450a | 1206 | |
262eb13a GS |
1207 | # Return |
1208 | if (wantarray()) { | |
1209 | ||
1210 | if ($options{'OPEN'}) { | |
1211 | return ($fh, $path); | |
1212 | } else { | |
1213 | return (undef, $path); | |
1214 | } | |
1215 | ||
1216 | } else { | |
1217 | ||
1218 | # Unlink the file. It is up to unlink0 to decide what to do with | |
1219 | # this (whether to unlink now or to defer until later) | |
1220 | unlink0($fh, $path) or croak "Error unlinking file $path using unlink0"; | |
669b450a | 1221 | |
262eb13a GS |
1222 | # Return just the filehandle. |
1223 | return $fh; | |
1224 | } | |
1225 | ||
1226 | ||
1227 | } | |
1228 | ||
1229 | =item B<tempdir> | |
1230 | ||
1231 | This is the recommended interface for creation of temporary directories. | |
1232 | The behaviour of the function depends on the arguments: | |
1233 | ||
1234 | $tempdir = tempdir(); | |
1235 | ||
1236 | Create a directory in tmpdir() (see L<File::Spec|File::Spec>). | |
1237 | ||
1238 | $tempdir = tempdir( $template ); | |
1239 | ||
1240 | Create a directory from the supplied template. This template is | |
1241 | similar to that described for tempfile(). `X' characters at the end | |
1242 | of the template are replaced with random letters to construct the | |
1243 | directory name. At least four `X' characters must be in the template. | |
1244 | ||
1245 | $tempdir = tempdir ( DIR => $dir ); | |
1246 | ||
1247 | Specifies the directory to use for the temporary directory. | |
1248 | The temporary directory name is derived from an internal template. | |
1249 | ||
1250 | $tempdir = tempdir ( $template, DIR => $dir ); | |
1251 | ||
1252 | Prepend the supplied directory name to the template. The template | |
1253 | should not include parent directory specifications itself. Any parent | |
1254 | directory specifications are removed from the template before | |
1255 | prepending the supplied directory. | |
1256 | ||
1257 | $tempdir = tempdir ( $template, TMPDIR => 1 ); | |
1258 | ||
be708cc0 | 1259 | Using the supplied template, create the temporary directory in |
262eb13a GS |
1260 | a standard location for temporary files. Equivalent to doing |
1261 | ||
1262 | $tempdir = tempdir ( $template, DIR => File::Spec->tmpdir); | |
1263 | ||
1264 | but shorter. Parent directory specifications are stripped from the | |
1265 | template itself. The C<TMPDIR> option is ignored if C<DIR> is set | |
1266 | explicitly. Additionally, C<TMPDIR> is implied if neither a template | |
1267 | nor a directory are supplied. | |
1268 | ||
1269 | $tempdir = tempdir( $template, CLEANUP => 1); | |
1270 | ||
be708cc0 | 1271 | Create a temporary directory using the supplied template, but |
262eb13a GS |
1272 | attempt to remove it (and all files inside it) when the program |
1273 | exits. Note that an attempt will be made to remove all files from | |
1274 | the directory even if they were not created by this module (otherwise | |
1275 | why ask to clean it up?). The directory removal is made with | |
1276 | the rmtree() function from the L<File::Path|File::Path> module. | |
1277 | Of course, if the template is not specified, the temporary directory | |
1278 | will be created in tmpdir() and will also be removed at program exit. | |
1279 | ||
1280 | =cut | |
1281 | ||
1282 | # ' | |
1283 | ||
1284 | sub tempdir { | |
1285 | ||
1286 | # Can not check for argument count since we can have any | |
1287 | # number of args | |
1288 | ||
1289 | # Default options | |
1290 | my %options = ( | |
1291 | "CLEANUP" => 0, # Remove directory on exit | |
1292 | "DIR" => '', # Root directory | |
1293 | "TMPDIR" => 0, # Use tempdir with template | |
1294 | ); | |
1295 | ||
1296 | # Check to see whether we have an odd or even number of arguments | |
1297 | my $template = (scalar(@_) % 2 == 1 ? shift(@_) : undef ); | |
1298 | ||
1299 | # Read the options and merge with defaults | |
1300 | %options = (%options, @_) if @_; | |
1301 | ||
1302 | # Modify or generate the template | |
1303 | ||
1304 | # Deal with the DIR and TMPDIR options | |
1305 | if (defined $template) { | |
1306 | ||
1307 | # Need to strip directory path if using DIR or TMPDIR | |
1308 | if ($options{'TMPDIR'} || $options{'DIR'}) { | |
1309 | ||
1310 | # Strip parent directory from the filename | |
51fc852f | 1311 | # |
262eb13a | 1312 | # There is no filename at the end |
51fc852f | 1313 | $template = VMS::Filespec::vmspath($template) if $^O eq 'VMS'; |
262eb13a GS |
1314 | my ($volume, $directories, undef) = File::Spec->splitpath( $template, 1); |
1315 | ||
1316 | # Last directory is then our template | |
1317 | $template = (File::Spec->splitdir($directories))[-1]; | |
1318 | ||
1319 | # Prepend the supplied directory or temp dir | |
1320 | if ($options{"DIR"}) { | |
1321 | ||
e4dfc136 | 1322 | $template = File::Spec->catdir($options{"DIR"}, $template); |
262eb13a GS |
1323 | |
1324 | } elsif ($options{TMPDIR}) { | |
1325 | ||
1326 | # Prepend tmpdir | |
1327 | $template = File::Spec->catdir(File::Spec->tmpdir, $template); | |
1328 | ||
1329 | } | |
1330 | ||
1331 | } | |
1332 | ||
1333 | } else { | |
1334 | ||
1335 | if ($options{"DIR"}) { | |
1336 | ||
1337 | $template = File::Spec->catdir($options{"DIR"}, TEMPXXX); | |
1338 | ||
1339 | } else { | |
669b450a | 1340 | |
262eb13a GS |
1341 | $template = File::Spec->catdir(File::Spec->tmpdir, TEMPXXX); |
1342 | ||
1343 | } | |
669b450a | 1344 | |
262eb13a GS |
1345 | } |
1346 | ||
1347 | # Create the directory | |
1348 | my $tempdir; | |
669b450a JH |
1349 | my $suffixlen = 0; |
1350 | if ($^O eq 'VMS') { # dir names can end in delimiters | |
1351 | $template =~ m/([\.\]:>]+)$/; | |
1352 | $suffixlen = length($1); | |
1353 | } | |
be708cc0 JH |
1354 | if ( ($^O eq 'MacOS') && (substr($template, -1) eq ':') ) { |
1355 | # dir name has a trailing ':' | |
1356 | ++$suffixlen; | |
1357 | } | |
0e939f40 | 1358 | |
28d6a1e0 TJ |
1359 | my $errstr; |
1360 | croak "Error in tempdir() using $template: $errstr" | |
262eb13a | 1361 | unless ((undef, $tempdir) = _gettemp($template, |
669b450a | 1362 | "open" => 0, |
262eb13a | 1363 | "mkdir"=> 1 , |
669b450a | 1364 | "suffixlen" => $suffixlen, |
28d6a1e0 | 1365 | "ErrStr" => \$errstr, |
669b450a JH |
1366 | ) ); |
1367 | ||
262eb13a | 1368 | # Install exit handler; must be dynamic to get lexical |
669b450a | 1369 | if ( $options{'CLEANUP'} && -d $tempdir) { |
262eb13a | 1370 | _deferred_unlink(undef, $tempdir, 1); |
669b450a | 1371 | } |
262eb13a GS |
1372 | |
1373 | # Return the dir name | |
1374 | return $tempdir; | |
1375 | ||
1376 | } | |
1377 | ||
1378 | =back | |
1379 | ||
1380 | =head1 MKTEMP FUNCTIONS | |
1381 | ||
be708cc0 | 1382 | The following functions are Perl implementations of the |
262eb13a GS |
1383 | mktemp() family of temp file generation system calls. |
1384 | ||
1385 | =over 4 | |
1386 | ||
1387 | =item B<mkstemp> | |
1388 | ||
1389 | Given a template, returns a filehandle to the temporary file and the name | |
1390 | of the file. | |
1391 | ||
1392 | ($fh, $name) = mkstemp( $template ); | |
1393 | ||
1394 | In scalar context, just the filehandle is returned. | |
1395 | ||
1396 | The template may be any filename with some number of X's appended | |
1397 | to it, for example F</tmp/temp.XXXX>. The trailing X's are replaced | |
1398 | with unique alphanumeric combinations. | |
1399 | ||
1400 | =cut | |
1401 | ||
1402 | ||
1403 | ||
1404 | sub mkstemp { | |
1405 | ||
1406 | croak "Usage: mkstemp(template)" | |
1407 | if scalar(@_) != 1; | |
1408 | ||
1409 | my $template = shift; | |
1410 | ||
28d6a1e0 TJ |
1411 | my ($fh, $path, $errstr); |
1412 | croak "Error in mkstemp using $template: $errstr" | |
669b450a JH |
1413 | unless (($fh, $path) = _gettemp($template, |
1414 | "open" => 1, | |
262eb13a GS |
1415 | "mkdir"=> 0 , |
1416 | "suffixlen" => 0, | |
28d6a1e0 | 1417 | "ErrStr" => \$errstr, |
262eb13a GS |
1418 | ) ); |
1419 | ||
1420 | if (wantarray()) { | |
1421 | return ($fh, $path); | |
1422 | } else { | |
1423 | return $fh; | |
1424 | } | |
1425 | ||
1426 | } | |
1427 | ||
1428 | ||
1429 | =item B<mkstemps> | |
1430 | ||
1431 | Similar to mkstemp(), except that an extra argument can be supplied | |
1432 | with a suffix to be appended to the template. | |
1433 | ||
1434 | ($fh, $name) = mkstemps( $template, $suffix ); | |
1435 | ||
1436 | For example a template of C<testXXXXXX> and suffix of C<.dat> | |
1437 | would generate a file similar to F<testhGji_w.dat>. | |
1438 | ||
1439 | Returns just the filehandle alone when called in scalar context. | |
1440 | ||
1441 | =cut | |
1442 | ||
1443 | sub mkstemps { | |
1444 | ||
1445 | croak "Usage: mkstemps(template, suffix)" | |
1446 | if scalar(@_) != 2; | |
1447 | ||
1448 | ||
1449 | my $template = shift; | |
1450 | my $suffix = shift; | |
1451 | ||
1452 | $template .= $suffix; | |
669b450a | 1453 | |
28d6a1e0 TJ |
1454 | my ($fh, $path, $errstr); |
1455 | croak "Error in mkstemps using $template: $errstr" | |
262eb13a | 1456 | unless (($fh, $path) = _gettemp($template, |
28d6a1e0 | 1457 | "open" => 1, |
262eb13a GS |
1458 | "mkdir"=> 0 , |
1459 | "suffixlen" => length($suffix), | |
28d6a1e0 | 1460 | "ErrStr" => \$errstr, |
262eb13a GS |
1461 | ) ); |
1462 | ||
1463 | if (wantarray()) { | |
1464 | return ($fh, $path); | |
1465 | } else { | |
1466 | return $fh; | |
1467 | } | |
1468 | ||
1469 | } | |
1470 | ||
1471 | =item B<mkdtemp> | |
1472 | ||
1473 | Create a directory from a template. The template must end in | |
1474 | X's that are replaced by the routine. | |
1475 | ||
1476 | $tmpdir_name = mkdtemp($template); | |
1477 | ||
1478 | Returns the name of the temporary directory created. | |
1479 | Returns undef on failure. | |
1480 | ||
1481 | Directory must be removed by the caller. | |
1482 | ||
1483 | =cut | |
1484 | ||
1485 | #' # for emacs | |
1486 | ||
1487 | sub mkdtemp { | |
1488 | ||
1489 | croak "Usage: mkdtemp(template)" | |
1490 | if scalar(@_) != 1; | |
262eb13a | 1491 | |
669b450a JH |
1492 | my $template = shift; |
1493 | my $suffixlen = 0; | |
1494 | if ($^O eq 'VMS') { # dir names can end in delimiters | |
1495 | $template =~ m/([\.\]:>]+)$/; | |
1496 | $suffixlen = length($1); | |
1497 | } | |
be708cc0 JH |
1498 | if ( ($^O eq 'MacOS') && (substr($template, -1) eq ':') ) { |
1499 | # dir name has a trailing ':' | |
1500 | ++$suffixlen; | |
1501 | } | |
28d6a1e0 TJ |
1502 | my ($junk, $tmpdir, $errstr); |
1503 | croak "Error creating temp directory from template $template\: $errstr" | |
262eb13a | 1504 | unless (($junk, $tmpdir) = _gettemp($template, |
669b450a | 1505 | "open" => 0, |
262eb13a | 1506 | "mkdir"=> 1 , |
669b450a | 1507 | "suffixlen" => $suffixlen, |
28d6a1e0 | 1508 | "ErrStr" => \$errstr, |
262eb13a GS |
1509 | ) ); |
1510 | ||
1511 | return $tmpdir; | |
1512 | ||
1513 | } | |
1514 | ||
1515 | =item B<mktemp> | |
1516 | ||
1517 | Returns a valid temporary filename but does not guarantee | |
1518 | that the file will not be opened by someone else. | |
1519 | ||
1520 | $unopened_file = mktemp($template); | |
1521 | ||
1522 | Template is the same as that required by mkstemp(). | |
1523 | ||
1524 | =cut | |
1525 | ||
1526 | sub mktemp { | |
1527 | ||
1528 | croak "Usage: mktemp(template)" | |
1529 | if scalar(@_) != 1; | |
1530 | ||
1531 | my $template = shift; | |
1532 | ||
28d6a1e0 TJ |
1533 | my ($tmpname, $junk, $errstr); |
1534 | croak "Error getting name to temp file from template $template: $errstr" | |
262eb13a | 1535 | unless (($junk, $tmpname) = _gettemp($template, |
669b450a | 1536 | "open" => 0, |
262eb13a GS |
1537 | "mkdir"=> 0 , |
1538 | "suffixlen" => 0, | |
28d6a1e0 | 1539 | "ErrStr" => \$errstr, |
262eb13a GS |
1540 | ) ); |
1541 | ||
1542 | return $tmpname; | |
1543 | } | |
1544 | ||
1545 | =back | |
1546 | ||
1547 | =head1 POSIX FUNCTIONS | |
1548 | ||
1549 | This section describes the re-implementation of the tmpnam() | |
be708cc0 | 1550 | and tmpfile() functions described in L<POSIX> |
262eb13a GS |
1551 | using the mkstemp() from this module. |
1552 | ||
1553 | Unlike the L<POSIX|POSIX> implementations, the directory used | |
1554 | for the temporary file is not specified in a system include | |
1555 | file (C<P_tmpdir>) but simply depends on the choice of tmpdir() | |
1556 | returned by L<File::Spec|File::Spec>. On some implementations this | |
1557 | location can be set using the C<TMPDIR> environment variable, which | |
1558 | may not be secure. | |
1559 | If this is a problem, simply use mkstemp() and specify a template. | |
1560 | ||
1561 | =over 4 | |
1562 | ||
1563 | =item B<tmpnam> | |
1564 | ||
1565 | When called in scalar context, returns the full name (including path) | |
1566 | of a temporary file (uses mktemp()). The only check is that the file does | |
1567 | not already exist, but there is no guarantee that that condition will | |
1568 | continue to apply. | |
1569 | ||
1570 | $file = tmpnam(); | |
1571 | ||
1572 | When called in list context, a filehandle to the open file and | |
1573 | a filename are returned. This is achieved by calling mkstemp() | |
1574 | after constructing a suitable template. | |
1575 | ||
1576 | ($fh, $file) = tmpnam(); | |
1577 | ||
1578 | If possible, this form should be used to prevent possible | |
1579 | race conditions. | |
1580 | ||
1581 | See L<File::Spec/tmpdir> for information on the choice of temporary | |
1582 | directory for a particular operating system. | |
1583 | ||
1584 | =cut | |
1585 | ||
1586 | sub tmpnam { | |
1587 | ||
1588 | # Retrieve the temporary directory name | |
1589 | my $tmpdir = File::Spec->tmpdir; | |
1590 | ||
1591 | croak "Error temporary directory is not writable" | |
1592 | if $tmpdir eq ''; | |
1593 | ||
1594 | # Use a ten character template and append to tmpdir | |
1595 | my $template = File::Spec->catfile($tmpdir, TEMPXXX); | |
669b450a | 1596 | |
262eb13a GS |
1597 | if (wantarray() ) { |
1598 | return mkstemp($template); | |
1599 | } else { | |
1600 | return mktemp($template); | |
1601 | } | |
1602 | ||
1603 | } | |
1604 | ||
1605 | =item B<tmpfile> | |
1606 | ||
c6d63c67 | 1607 | Returns the filehandle of a temporary file. |
262eb13a GS |
1608 | |
1609 | $fh = tmpfile(); | |
1610 | ||
1611 | The file is removed when the filehandle is closed or when the program | |
1612 | exits. No access to the filename is provided. | |
1613 | ||
0e939f40 JH |
1614 | If the temporary file can not be created undef is returned. |
1615 | Currently this command will probably not work when the temporary | |
1616 | directory is on an NFS file system. | |
1617 | ||
262eb13a GS |
1618 | =cut |
1619 | ||
1620 | sub tmpfile { | |
1621 | ||
91e74348 | 1622 | # Simply call tmpnam() in a list context |
262eb13a GS |
1623 | my ($fh, $file) = tmpnam(); |
1624 | ||
1625 | # Make sure file is removed when filehandle is closed | |
0e939f40 JH |
1626 | # This will fail on NFS |
1627 | unlink0($fh, $file) | |
1628 | or return undef; | |
262eb13a GS |
1629 | |
1630 | return $fh; | |
1631 | ||
1632 | } | |
1633 | ||
1634 | =back | |
1635 | ||
1636 | =head1 ADDITIONAL FUNCTIONS | |
1637 | ||
1638 | These functions are provided for backwards compatibility | |
1639 | with common tempfile generation C library functions. | |
1640 | ||
1641 | They are not exported and must be addressed using the full package | |
be708cc0 | 1642 | name. |
262eb13a GS |
1643 | |
1644 | =over 4 | |
1645 | ||
1646 | =item B<tempnam> | |
1647 | ||
1648 | Return the name of a temporary file in the specified directory | |
1649 | using a prefix. The file is guaranteed not to exist at the time | |
be708cc0 | 1650 | the function was called, but such guarantees are good for one |
262eb13a GS |
1651 | clock tick only. Always use the proper form of C<sysopen> |
1652 | with C<O_CREAT | O_EXCL> if you must open such a filename. | |
1653 | ||
1654 | $filename = File::Temp::tempnam( $dir, $prefix ); | |
1655 | ||
1656 | Equivalent to running mktemp() with $dir/$prefixXXXXXXXX | |
be708cc0 | 1657 | (using unix file convention as an example) |
262eb13a GS |
1658 | |
1659 | Because this function uses mktemp(), it can suffer from race conditions. | |
1660 | ||
1661 | =cut | |
1662 | ||
1663 | sub tempnam { | |
1664 | ||
1665 | croak 'Usage tempnam($dir, $prefix)' unless scalar(@_) == 2; | |
1666 | ||
1667 | my ($dir, $prefix) = @_; | |
1668 | ||
1669 | # Add a string to the prefix | |
1670 | $prefix .= 'XXXXXXXX'; | |
1671 | ||
1672 | # Concatenate the directory to the file | |
1673 | my $template = File::Spec->catfile($dir, $prefix); | |
1674 | ||
1675 | return mktemp($template); | |
1676 | ||
1677 | } | |
1678 | ||
1679 | =back | |
1680 | ||
1681 | =head1 UTILITY FUNCTIONS | |
1682 | ||
1683 | Useful functions for dealing with the filehandle and filename. | |
1684 | ||
1685 | =over 4 | |
1686 | ||
1687 | =item B<unlink0> | |
1688 | ||
1689 | Given an open filehandle and the associated filename, make a safe | |
1690 | unlink. This is achieved by first checking that the filename and | |
1691 | filehandle initially point to the same file and that the number of | |
1692 | links to the file is 1 (all fields returned by stat() are compared). | |
1693 | Then the filename is unlinked and the filehandle checked once again to | |
1694 | verify that the number of links on that file is now 0. This is the | |
1695 | closest you can come to making sure that the filename unlinked was the | |
1696 | same as the file whose descriptor you hold. | |
1697 | ||
1698 | unlink0($fh, $path) or die "Error unlinking file $path safely"; | |
1699 | ||
1700 | Returns false on error. The filehandle is not closed since on some | |
1701 | occasions this is not required. | |
1702 | ||
1703 | On some platforms, for example Windows NT, it is not possible to | |
1704 | unlink an open file (the file must be closed first). On those | |
1c19c868 JH |
1705 | platforms, the actual unlinking is deferred until the program ends and |
1706 | good status is returned. A check is still performed to make sure that | |
1707 | the filehandle and filename are pointing to the same thing (but not at | |
1708 | the time the end block is executed since the deferred removal may not | |
1709 | have access to the filehandle). | |
262eb13a GS |
1710 | |
1711 | Additionally, on Windows NT not all the fields returned by stat() can | |
51fc852f TJ |
1712 | be compared. For example, the C<dev> and C<rdev> fields seem to be |
1713 | different. Also, it seems that the size of the file returned by stat() | |
262eb13a GS |
1714 | does not always agree, with C<stat(FH)> being more accurate than |
1715 | C<stat(filename)>, presumably because of caching issues even when | |
1716 | using autoflush (this is usually overcome by waiting a while after | |
1717 | writing to the tempfile before attempting to C<unlink0> it). | |
1718 | ||
1c19c868 JH |
1719 | Finally, on NFS file systems the link count of the file handle does |
1720 | not always go to zero immediately after unlinking. Currently, this | |
1721 | command is expected to fail on NFS disks. | |
1722 | ||
262eb13a GS |
1723 | =cut |
1724 | ||
1725 | sub unlink0 { | |
1726 | ||
1727 | croak 'Usage: unlink0(filehandle, filename)' | |
1728 | unless scalar(@_) == 2; | |
1729 | ||
1730 | # Read args | |
1731 | my ($fh, $path) = @_; | |
1732 | ||
4a094b80 JH |
1733 | cmpstat($fh, $path) or return 0; |
1734 | ||
1735 | # attempt remove the file (does not work on some platforms) | |
1736 | if (_can_unlink_opened_file()) { | |
1737 | # XXX: do *not* call this on a directory; possible race | |
1738 | # resulting in recursive removal | |
1739 | croak "unlink0: $path has become a directory!" if -d $path; | |
1740 | unlink($path) or return 0; | |
1741 | ||
1742 | # Stat the filehandle | |
1743 | my @fh = stat $fh; | |
1744 | ||
1745 | print "Link count = $fh[3] \n" if $DEBUG; | |
1746 | ||
1747 | # Make sure that the link count is zero | |
1748 | # - Cygwin provides deferred unlinking, however, | |
1749 | # on Win9x the link count remains 1 | |
1750 | # On NFS the link count may still be 1 but we cant know that | |
1751 | # we are on NFS | |
1752 | return ( $fh[3] == 0 or $^O eq 'cygwin' ? 1 : 0); | |
1753 | ||
1754 | } else { | |
1755 | _deferred_unlink($fh, $path, 0); | |
1756 | return 1; | |
1757 | } | |
1758 | ||
1759 | } | |
1760 | ||
1761 | =item B<cmpstat> | |
1762 | ||
1763 | Compare C<stat> of filehandle with C<stat> of provided filename. This | |
1764 | can be used to check that the filename and filehandle initially point | |
1765 | to the same file and that the number of links to the file is 1 (all | |
1766 | fields returned by stat() are compared). | |
1767 | ||
1768 | cmpstat($fh, $path) or die "Error comparing handle with file"; | |
1769 | ||
1770 | Returns false if the stat information differs or if the link count is | |
1771 | greater than 1. | |
1772 | ||
1773 | On certain platofms, eg Windows, not all the fields returned by stat() | |
1774 | can be compared. For example, the C<dev> and C<rdev> fields seem to be | |
1775 | different in Windows. Also, it seems that the size of the file | |
1776 | returned by stat() does not always agree, with C<stat(FH)> being more | |
1777 | accurate than C<stat(filename)>, presumably because of caching issues | |
1778 | even when using autoflush (this is usually overcome by waiting a while | |
1779 | after writing to the tempfile before attempting to C<unlink0> it). | |
1780 | ||
1781 | Not exported by default. | |
1782 | ||
1783 | =cut | |
1784 | ||
1785 | sub cmpstat { | |
1786 | ||
1787 | croak 'Usage: cmpstat(filehandle, filename)' | |
1788 | unless scalar(@_) == 2; | |
1789 | ||
1790 | # Read args | |
1791 | my ($fh, $path) = @_; | |
1792 | ||
1793 | warn "Comparing stat\n" | |
262eb13a GS |
1794 | if $DEBUG; |
1795 | ||
4a094b80 JH |
1796 | # Stat the filehandle - which may be closed if someone has manually |
1797 | # closed the file. Can not turn off warnings without using $^W | |
1798 | # unless we upgrade to 5.006 minimum requirement | |
1799 | my @fh; | |
1800 | { | |
1801 | local ($^W) = 0; | |
1802 | @fh = stat $fh; | |
1803 | } | |
1804 | return unless @fh; | |
262eb13a GS |
1805 | |
1806 | if ($fh[3] > 1 && $^W) { | |
28d6a1e0 | 1807 | carp "unlink0: fstat found too many links; SB=@fh" if $^W; |
669b450a | 1808 | } |
262eb13a GS |
1809 | |
1810 | # Stat the path | |
1811 | my @path = stat $path; | |
1812 | ||
1813 | unless (@path) { | |
1814 | carp "unlink0: $path is gone already" if $^W; | |
1815 | return; | |
669b450a | 1816 | } |
262eb13a GS |
1817 | |
1818 | # this is no longer a file, but may be a directory, or worse | |
1819 | unless (-f _) { | |
1820 | confess "panic: $path is no longer a file: SB=@fh"; | |
669b450a | 1821 | } |
262eb13a GS |
1822 | |
1823 | # Do comparison of each member of the array | |
1824 | # On WinNT dev and rdev seem to be different | |
1825 | # depending on whether it is a file or a handle. | |
1826 | # Cannot simply compare all members of the stat return | |
1827 | # Select the ones we can use | |
1828 | my @okstat = (0..$#fh); # Use all by default | |
1829 | if ($^O eq 'MSWin32') { | |
1830 | @okstat = (1,2,3,4,5,7,8,9,10); | |
669b450a | 1831 | } elsif ($^O eq 'os2') { |
d62e1b7f | 1832 | @okstat = (0, 2..$#fh); |
51fc852f TJ |
1833 | } elsif ($^O eq 'VMS') { # device and file ID are sufficient |
1834 | @okstat = (0, 1); | |
6bbf1b34 | 1835 | } elsif ($^O eq 'dos') { |
4a094b80 JH |
1836 | @okstat = (0,2..7,11..$#fh); |
1837 | } elsif ($^O eq 'mpeix') { | |
1838 | @okstat = (0..4,8..10); | |
262eb13a GS |
1839 | } |
1840 | ||
1841 | # Now compare each entry explicitly by number | |
1842 | for (@okstat) { | |
1843 | print "Comparing: $_ : $fh[$_] and $path[$_]\n" if $DEBUG; | |
d62e1b7f JH |
1844 | # Use eq rather than == since rdev, blksize, and blocks (6, 11, |
1845 | # and 12) will be '' on platforms that do not support them. This | |
1846 | # is fine since we are only comparing integers. | |
669b450a | 1847 | unless ($fh[$_] eq $path[$_]) { |
262eb13a GS |
1848 | warn "Did not match $_ element of stat\n" if $DEBUG; |
1849 | return 0; | |
1850 | } | |
1851 | } | |
669b450a | 1852 | |
4a094b80 JH |
1853 | return 1; |
1854 | } | |
262eb13a | 1855 | |
4a094b80 | 1856 | =item B<unlink1> |
262eb13a | 1857 | |
4a094b80 JH |
1858 | Similar to C<unlink0> except after file comparison using cmpstat, the |
1859 | filehandle is closed prior to attempting to unlink the file. This | |
1860 | allows the file to be removed without using an END block, but does | |
1861 | mean that the post-unlink comparison of the filehandle state provided | |
1862 | by C<unlink0> is not available. | |
262eb13a | 1863 | |
4a094b80 | 1864 | unlink1($fh, $path) or die "Error closing and unlinking file"; |
262eb13a | 1865 | |
4a094b80 JH |
1866 | Usually called from the object destructor when using the OO interface. |
1867 | ||
1868 | Not exported by default. | |
1869 | ||
1870 | =cut | |
262eb13a | 1871 | |
4a094b80 JH |
1872 | sub unlink1 { |
1873 | croak 'Usage: unlink1(filehandle, filename)' | |
1874 | unless scalar(@_) == 2; | |
1875 | ||
1876 | # Read args | |
1877 | my ($fh, $path) = @_; | |
1878 | ||
1879 | cmpstat($fh, $path) or return 0; | |
1880 | ||
1881 | # Close the file | |
1882 | close( $fh ) or return 0; | |
1883 | ||
1884 | # remove the file | |
1885 | return unlink($path); | |
262eb13a GS |
1886 | } |
1887 | ||
1888 | =back | |
1889 | ||
1890 | =head1 PACKAGE VARIABLES | |
1891 | ||
1892 | These functions control the global state of the package. | |
1893 | ||
1894 | =over 4 | |
1895 | ||
1896 | =item B<safe_level> | |
1897 | ||
1898 | Controls the lengths to which the module will go to check the safety of the | |
1899 | temporary file or directory before proceeding. | |
1900 | Options are: | |
1901 | ||
1902 | =over 8 | |
1903 | ||
1904 | =item STANDARD | |
1905 | ||
1906 | Do the basic security measures to ensure the directory exists and | |
1907 | is writable, that the umask() is fixed before opening of the file, | |
1908 | that temporary files are opened only if they do not already exist, and | |
1909 | that possible race conditions are avoided. Finally the L<unlink0|"unlink0"> | |
1910 | function is used to remove files safely. | |
1911 | ||
1912 | =item MEDIUM | |
1913 | ||
1914 | In addition to the STANDARD security, the output directory is checked | |
1915 | to make sure that it is owned either by root or the user running the | |
1916 | program. If the directory is writable by group or by other, it is then | |
1917 | checked to make sure that the sticky bit is set. | |
1918 | ||
1919 | Will not work on platforms that do not support the C<-k> test | |
1920 | for sticky bit. | |
1921 | ||
1922 | =item HIGH | |
1923 | ||
1924 | In addition to the MEDIUM security checks, also check for the | |
1925 | possibility of ``chown() giveaway'' using the L<POSIX|POSIX> | |
1926 | sysconf() function. If this is a possibility, each directory in the | |
be708cc0 | 1927 | path is checked in turn for safeness, recursively walking back to the |
262eb13a GS |
1928 | root directory. |
1929 | ||
1930 | For platforms that do not support the L<POSIX|POSIX> | |
be708cc0 | 1931 | C<_PC_CHOWN_RESTRICTED> symbol (for example, Windows NT) it is |
262eb13a GS |
1932 | assumed that ``chown() giveaway'' is possible and the recursive test |
1933 | is performed. | |
1934 | ||
1935 | =back | |
1936 | ||
1937 | The level can be changed as follows: | |
1938 | ||
1939 | File::Temp->safe_level( File::Temp::HIGH ); | |
1940 | ||
1941 | The level constants are not exported by the module. | |
1942 | ||
1943 | Currently, you must be running at least perl v5.6.0 in order to | |
be708cc0 | 1944 | run with MEDIUM or HIGH security. This is simply because the |
262eb13a GS |
1945 | safety tests use functions from L<Fcntl|Fcntl> that are not |
1946 | available in older versions of perl. The problem is that the version | |
1947 | number for Fcntl is the same in perl 5.6.0 and in 5.005_03 even though | |
1c19c868 JH |
1948 | they are different versions. |
1949 | ||
1950 | On systems that do not support the HIGH or MEDIUM safety levels | |
1951 | (for example Win NT or OS/2) any attempt to change the level will | |
1952 | be ignored. The decision to ignore rather than raise an exception | |
1953 | allows portable programs to be written with high security in mind | |
1954 | for the systems that can support this without those programs failing | |
1955 | on systems where the extra tests are irrelevant. | |
1956 | ||
1957 | If you really need to see whether the change has been accepted | |
1958 | simply examine the return value of C<safe_level>. | |
1959 | ||
1960 | $newlevel = File::Temp->safe_level( File::Temp::HIGH ); | |
be708cc0 | 1961 | die "Could not change to high security" |
1c19c868 | 1962 | if $newlevel != File::Temp::HIGH; |
262eb13a GS |
1963 | |
1964 | =cut | |
1965 | ||
1966 | { | |
1967 | # protect from using the variable itself | |
1968 | my $LEVEL = STANDARD; | |
1969 | sub safe_level { | |
1970 | my $self = shift; | |
be708cc0 | 1971 | if (@_) { |
262eb13a GS |
1972 | my $level = shift; |
1973 | if (($level != STANDARD) && ($level != MEDIUM) && ($level != HIGH)) { | |
28d6a1e0 | 1974 | carp "safe_level: Specified level ($level) not STANDARD, MEDIUM or HIGH - ignoring\n" if $^W; |
262eb13a | 1975 | } else { |
1c19c868 | 1976 | # Dont allow this on perl 5.005 or earlier |
262eb13a GS |
1977 | if ($] < 5.006 && $level != STANDARD) { |
1978 | # Cant do MEDIUM or HIGH checks | |
1979 | croak "Currently requires perl 5.006 or newer to do the safe checks"; | |
1980 | } | |
1c19c868 JH |
1981 | # Check that we are allowed to change level |
1982 | # Silently ignore if we can not. | |
1983 | $LEVEL = $level if _can_do_level($level); | |
262eb13a GS |
1984 | } |
1985 | } | |
1986 | return $LEVEL; | |
1987 | } | |
1988 | } | |
1989 | ||
1990 | =item TopSystemUID | |
1991 | ||
1992 | This is the highest UID on the current system that refers to a root | |
be708cc0 JH |
1993 | UID. This is used to make sure that the temporary directory is |
1994 | owned by a system UID (C<root>, C<bin>, C<sys> etc) rather than | |
262eb13a GS |
1995 | simply by root. |
1996 | ||
1997 | This is required since on many unix systems C</tmp> is not owned | |
1998 | by root. | |
1999 | ||
2000 | Default is to assume that any UID less than or equal to 10 is a root | |
2001 | UID. | |
2002 | ||
2003 | File::Temp->top_system_uid(10); | |
2004 | my $topid = File::Temp->top_system_uid; | |
2005 | ||
2006 | This value can be adjusted to reduce security checking if required. | |
2007 | The value is only relevant when C<safe_level> is set to MEDIUM or higher. | |
2008 | ||
2009 | =back | |
2010 | ||
2011 | =cut | |
2012 | ||
2013 | { | |
2014 | my $TopSystemUID = 10; | |
0c52c6a9 | 2015 | $TopSystemUID = 197108 if $^O eq 'interix'; # "Administrator" |
262eb13a GS |
2016 | sub top_system_uid { |
2017 | my $self = shift; | |
2018 | if (@_) { | |
2019 | my $newuid = shift; | |
2020 | croak "top_system_uid: UIDs should be numeric" | |
2021 | unless $newuid =~ /^\d+$/s; | |
2022 | $TopSystemUID = $newuid; | |
2023 | } | |
2024 | return $TopSystemUID; | |
2025 | } | |
2026 | } | |
2027 | ||
2028 | =head1 WARNING | |
2029 | ||
2030 | For maximum security, endeavour always to avoid ever looking at, | |
2031 | touching, or even imputing the existence of the filename. You do not | |
2032 | know that that filename is connected to the same file as the handle | |
2033 | you have, and attempts to check this can only trigger more race | |
2034 | conditions. It's far more secure to use the filehandle alone and | |
2035 | dispense with the filename altogether. | |
2036 | ||
2037 | If you need to pass the handle to something that expects a filename | |
2038 | then, on a unix system, use C<"/dev/fd/" . fileno($fh)> for arbitrary | |
2039 | programs, or more generally C<< "+<=&" . fileno($fh) >> for Perl | |
2040 | programs. You will have to clear the close-on-exec bit on that file | |
2041 | descriptor before passing it to another process. | |
2042 | ||
2043 | use Fcntl qw/F_SETFD F_GETFD/; | |
2044 | fcntl($tmpfh, F_SETFD, 0) | |
2045 | or die "Can't clear close-on-exec flag on temp fh: $!\n"; | |
2046 | ||
09d7a2f9 TJ |
2047 | =head2 Temporary files and NFS |
2048 | ||
2049 | Some problems are associated with using temporary files that reside | |
2050 | on NFS file systems and it is recommended that a local filesystem | |
2051 | is used whenever possible. Some of the security tests will most probably | |
2052 | fail when the temp file is not local. Additionally, be aware that | |
2053 | the performance of I/O operations over NFS will not be as good as for | |
2054 | a local disk. | |
2055 | ||
262eb13a GS |
2056 | =head1 HISTORY |
2057 | ||
2058 | Originally began life in May 1999 as an XS interface to the system | |
e77f578c | 2059 | mkstemp() function. In March 2000, the OpenBSD mkstemp() code was |
262eb13a GS |
2060 | translated to Perl for total control of the code's |
2061 | security checking, to ensure the presence of the function regardless of | |
2062 | operating system and to help with portability. | |
2063 | ||
2064 | =head1 SEE ALSO | |
2065 | ||
2066 | L<POSIX/tmpnam>, L<POSIX/tmpfile>, L<File::Spec>, L<File::Path> | |
2067 | ||
be708cc0 | 2068 | See L<IO::File> and L<File::MkTemp> for different implementations of |
09d7a2f9 | 2069 | temporary file handling. |
262eb13a GS |
2070 | |
2071 | =head1 AUTHOR | |
2072 | ||
21cc0ee1 | 2073 | Tim Jenness E<lt>tjenness@cpan.orgE<gt> |
262eb13a | 2074 | |
21cc0ee1 | 2075 | Copyright (C) 1999-2003 Tim Jenness and the UK Particle Physics and |
262eb13a GS |
2076 | Astronomy Research Council. All Rights Reserved. This program is free |
2077 | software; you can redistribute it and/or modify it under the same | |
2078 | terms as Perl itself. | |
2079 | ||
be708cc0 | 2080 | Original Perl implementation loosely based on the OpenBSD C code for |
262eb13a GS |
2081 | mkstemp(). Thanks to Tom Christiansen for suggesting that this module |
2082 | should be written and providing ideas for code improvements and | |
2083 | security enhancements. | |
2084 | ||
2085 | =cut | |
2086 | ||
262eb13a | 2087 | 1; |