5 File::Temp - return name and handle of a temporary file safely
11 This section is at the top in order to provide easier access to
12 porters. It is not expected to be rendered by a standard pod
13 formatting tool. Please skip straight to the SYNOPSIS section if you
14 are not trying to port this module to a new platform.
16 This module is designed to be portable across operating systems and it
17 currently supports Unix, VMS, DOS, OS/2, Windows and Mac OS
18 (Classic). When porting to a new OS there are generally three main
19 issues that have to be solved:
25 Can the OS unlink an open file? If it can not then the
26 C<_can_unlink_opened_file> method should be modified.
30 Are the return values from C<stat> reliable? By default all the
31 return values from C<stat> are compared when unlinking a temporary
32 file using the filename and the handle. Operating systems other than
33 unix do not always have valid entries in all fields. If C<unlink0> fails
34 then the C<stat> comparison should be modified accordingly.
38 Security. Systems that can not support a test for the sticky bit
39 on a directory can not use the MEDIUM and HIGH security tests.
40 The C<_can_do_level> method should be modified accordingly.
48 use File::Temp qw/ tempfile tempdir /;
51 ($fh, $filename) = tempfile();
53 ($fh, $filename) = tempfile( $template, DIR => $dir);
54 ($fh, $filename) = tempfile( $template, SUFFIX => '.dat');
57 $dir = tempdir( CLEANUP => 1 );
58 ($fh, $filename) = tempfile( DIR => $dir );
64 use File::Temp qw/ :seekable /;
66 $fh = new File::Temp();
67 $fname = $fh->filename;
69 $fh = new File::Temp(TEMPLATE => $template);
70 $fname = $fh->filename;
72 $tmp = new File::Temp( UNLINK => 0, SUFFIX => '.dat' );
73 print $tmp "Some data\n";
74 print "Filename is $tmp\n";
75 $tmp->seek( 0, SEEK_END );
77 The following interfaces are provided for compatibility with
78 existing APIs. They should not be used in new code.
82 use File::Temp qw/ :mktemp /;
84 ($fh, $file) = mkstemp( "tmpfileXXXXX" );
85 ($fh, $file) = mkstemps( "tmpfileXXXXXX", $suffix);
87 $tmpdir = mkdtemp( $template );
89 $unopened_file = mktemp( $template );
93 use File::Temp qw/ :POSIX /;
98 ($fh, $file) = tmpnam();
100 Compatibility functions:
102 $unopened_file = File::Temp::tempnam( $dir, $pfx );
106 C<File::Temp> can be used to create and open temporary files in a safe
107 way. There is both a function interface and an object-oriented
108 interface. The File::Temp constructor or the tempfile() function can
109 be used to return the name and the open filehandle of a temporary
110 file. The tempdir() function can be used to create a temporary
113 The security aspect of temporary file creation is emphasized such that
114 a filehandle and filename are returned together. This helps guarantee
115 that a race condition can not occur where the temporary file is
116 created by another process between checking for the existence of the
117 file and its opening. Additional security levels are provided to
118 check, for example, that the sticky bit is set on world writable
119 directories. See L<"safe_level"> for more information.
121 For compatibility with popular C library functions, Perl implementations of
122 the mkstemp() family of functions are provided. These are, mkstemp(),
123 mkstemps(), mkdtemp() and mktemp().
125 Additionally, implementations of the standard L<POSIX|POSIX>
126 tmpnam() and tmpfile() functions are provided if required.
128 Implementations of mktemp(), tmpnam(), and tempnam() are provided,
129 but should be used with caution since they return only a filename
130 that was valid when function was called, so cannot guarantee
131 that the file will not exist by the time the caller opens the filename.
135 # 5.6.0 gives us S_IWOTH, S_IWGRP, our and auto-vivifying filehandls
136 # People would like a version on 5.004 so give them what they want :-)
141 use File::Path qw/ rmtree /;
143 use IO::Seekable; # For SEEK_*
145 require VMS::Stdio if $^O eq 'VMS';
147 # pre-emptively load Carp::Heavy. If we don't when we run out of file
148 # handles and attempt to call croak() we get an error message telling
149 # us that Carp::Heavy won't load rather than an error telling us we
150 # have run out of file handles. We either preload croak() or we
151 # switch the calls to croak from _gettemp() to use die.
154 # Need the Symbol package if we are running older perl
155 require Symbol if $] < 5.006;
157 ### For the OO interface
158 use base qw/ IO::Handle IO::Seekable /;
159 use overload '""' => "STRINGIFY", fallback => 1;
161 # use 'our' on v5.6.0
162 use vars qw($VERSION @EXPORT_OK %EXPORT_TAGS $DEBUG $KEEP_ALL);
167 # We are exporting functions
169 use base qw/Exporter/;
171 # Export list - to allow fine tuning of export table
189 # Groups of functions for export
192 'POSIX' => [qw/ tmpnam tmpfile /],
193 'mktemp' => [qw/ mktemp mkstemp mkstemps mkdtemp/],
194 'seekable' => [qw/ SEEK_SET SEEK_CUR SEEK_END /],
197 # add contents of these tags to @EXPORT
198 Exporter::export_tags('POSIX','mktemp','seekable');
204 # This is a list of characters that can be used in random filenames
206 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
207 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
208 0 1 2 3 4 5 6 7 8 9 _
211 # Maximum number of tries to make a temp file before failing
213 use constant MAX_TRIES => 1000;
215 # Minimum number of X characters that should be in a template
216 use constant MINX => 4;
218 # Default template when no template supplied
220 use constant TEMPXXX => 'X' x 10;
222 # Constants for the security level
224 use constant STANDARD => 0;
225 use constant MEDIUM => 1;
226 use constant HIGH => 2;
228 # OPENFLAGS. If we defined the flag to use with Sysopen here this gives
229 # us an optimisation when many temporary files are requested
231 my $OPENFLAGS = O_CREAT | O_EXCL | O_RDWR;
233 unless ($^O eq 'MacOS') {
234 for my $oflag (qw/ NOFOLLOW BINARY LARGEFILE EXLOCK NOINHERIT /) {
235 my ($bit, $func) = (0, "Fcntl::O_" . $oflag);
237 $OPENFLAGS |= $bit if eval {
238 # Make sure that redefined die handlers do not cause problems
240 local $SIG{__DIE__} = sub {};
241 local $SIG{__WARN__} = sub {};
248 # On some systems the O_TEMPORARY flag can be used to tell the OS
249 # to automatically remove the file when it is closed. This is fine
250 # in most cases but not if tempfile is called with UNLINK=>0 and
251 # the filename is requested -- in the case where the filename is to
252 # be passed to another routine. This happens on windows. We overcome
253 # this by using a second open flags variable
255 my $OPENTEMPFLAGS = $OPENFLAGS;
256 unless ($^O eq 'MacOS') {
257 for my $oflag (qw/ TEMPORARY /) {
258 my ($bit, $func) = (0, "Fcntl::O_" . $oflag);
260 $OPENTEMPFLAGS |= $bit if eval {
261 # Make sure that redefined die handlers do not cause problems
263 local $SIG{__DIE__} = sub {};
264 local $SIG{__WARN__} = sub {};
271 # INTERNAL ROUTINES - not to be used outside of package
273 # Generic routine for getting a temporary filename
274 # modelled on OpenBSD _gettemp() in mktemp.c
276 # The template must contain X's that are to be replaced
277 # with the random values
281 # TEMPLATE - string containing the XXXXX's that is converted
282 # to a random filename and opened if required
284 # Optionally, a hash can also be supplied containing specific options
285 # "open" => if true open the temp file, else just return the name
287 # "mkdir"=> if true, we are creating a temp directory rather than tempfile
289 # "suffixlen" => number of characters at end of PATH to be ignored.
291 # "unlink_on_close" => indicates that, if possible, the OS should remove
292 # the file as soon as it is closed. Usually indicates
293 # use of the O_TEMPORARY flag to sysopen.
294 # Usually irrelevant on unix
296 # Optionally a reference to a scalar can be passed into the function
297 # On error this will be used to store the reason for the error
298 # "ErrStr" => \$errstr
300 # "open" and "mkdir" can not both be true
301 # "unlink_on_close" is not used when "mkdir" is true.
303 # The default options are equivalent to mktemp().
306 # filehandle - open file handle (if called with doopen=1, else undef)
307 # temp name - name of the temp file or directory
310 # ($fh, $name) = _gettemp($template, "open" => 1);
312 # for the current version, failures are associated with
313 # stored in an error string and returned to give the reason whilst debugging
314 # This routine is not called by any external function
317 croak 'Usage: ($fh, $name) = _gettemp($template, OPTIONS);'
318 unless scalar(@_) >= 1;
320 # the internal error string - expect it to be overridden
321 # Need this in case the caller decides not to supply us a value
322 # need an anonymous scalar
330 "unlink_on_close" => 0,
331 "ErrStr" => \$tempErrStr,
335 my $template = shift;
336 if (ref($template)) {
337 # Use a warning here since we have not yet merged ErrStr
338 carp "File::Temp::_gettemp: template must not be a reference";
342 # Check that the number of entries on stack are even
343 if (scalar(@_) % 2 != 0) {
344 # Use a warning here since we have not yet merged ErrStr
345 carp "File::Temp::_gettemp: Must have even number of options";
349 # Read the options and merge with defaults
350 %options = (%options, @_) if @_;
352 # Make sure the error string is set to undef
353 ${$options{ErrStr}} = undef;
355 # Can not open the file and make a directory in a single call
356 if ($options{"open"} && $options{"mkdir"}) {
357 ${$options{ErrStr}} = "doopen and domkdir can not both be true\n";
361 # Find the start of the end of the Xs (position of last X)
362 # Substr starts from 0
363 my $start = length($template) - 1 - $options{"suffixlen"};
365 # Check that we have at least MINX x X (e.g. 'XXXX") at the end of the string
366 # (taking suffixlen into account). Any fewer is insecure.
368 # Do it using substr - no reason to use a pattern match since
369 # we know where we are looking and what we are looking for
371 if (substr($template, $start - MINX + 1, MINX) ne 'X' x MINX) {
372 ${$options{ErrStr}} = "The template must end with at least ".
373 MINX . " 'X' characters\n";
377 # Replace all the X at the end of the substring with a
378 # random character or just all the XX at the end of a full string.
379 # Do it as an if, since the suffix adjusts which section to replace
380 # and suffixlen=0 returns nothing if used in the substr directly
381 # and generate a full path from the template
383 my $path = _replace_XX($template, $options{"suffixlen"});
386 # Split the path into constituent parts - eventually we need to check
387 # whether the directory exists
388 # We need to know whether we are making a temp directory
391 my ($volume, $directories, $file);
392 my $parent; # parent directory
393 if ($options{"mkdir"}) {
394 # There is no filename at the end
395 ($volume, $directories, $file) = File::Spec->splitpath( $path, 1);
397 # The parent is then $directories without the last directory
398 # Split the directory and put it back together again
399 my @dirs = File::Spec->splitdir($directories);
401 # If @dirs only has one entry (i.e. the directory template) that means
402 # we are in the current directory
404 $parent = File::Spec->curdir;
407 if ($^O eq 'VMS') { # need volume to avoid relative dir spec
408 $parent = File::Spec->catdir($volume, @dirs[0..$#dirs-1]);
409 $parent = 'sys$disk:[]' if $parent eq '';
412 # Put it back together without the last one
413 $parent = File::Spec->catdir(@dirs[0..$#dirs-1]);
415 # ...and attach the volume (no filename)
416 $parent = File::Spec->catpath($volume, $parent, '');
423 # Get rid of the last filename (use File::Basename for this?)
424 ($volume, $directories, $file) = File::Spec->splitpath( $path );
426 # Join up without the file part
427 $parent = File::Spec->catpath($volume,$directories,'');
429 # If $parent is empty replace with curdir
430 $parent = File::Spec->curdir
431 unless $directories ne '';
435 # Check that the parent directories exist
436 # Do this even for the case where we are simply returning a name
437 # not a file -- no point returning a name that includes a directory
438 # that does not exist or is not writable
440 unless (-d $parent) {
441 ${$options{ErrStr}} = "Parent directory ($parent) is not a directory";
444 unless (-w $parent) {
445 ${$options{ErrStr}} = "Parent directory ($parent) is not writable\n";
450 # Check the stickiness of the directory and chown giveaway if required
451 # If the directory is world writable the sticky bit
454 if (File::Temp->safe_level == MEDIUM) {
456 unless (_is_safe($parent,\$safeerr)) {
457 ${$options{ErrStr}} = "Parent directory ($parent) is not safe ($safeerr)";
460 } elsif (File::Temp->safe_level == HIGH) {
462 unless (_is_verysafe($parent, \$safeerr)) {
463 ${$options{ErrStr}} = "Parent directory ($parent) is not safe ($safeerr)";
469 # Now try MAX_TRIES time to open the file
470 for (my $i = 0; $i < MAX_TRIES; $i++) {
472 # Try to open the file if requested
473 if ($options{"open"}) {
476 # If we are running before perl5.6.0 we can not auto-vivify
478 $fh = &Symbol::gensym;
481 # Try to make sure this will be marked close-on-exec
482 # XXX: Win32 doesn't respect this, nor the proper fcntl,
483 # but may have O_NOINHERIT. This may or may not be in Fcntl.
486 # Attempt to open the file
487 my $open_success = undef;
488 if ( $^O eq 'VMS' and $options{"unlink_on_close"} && !$KEEP_ALL) {
489 # make it auto delete on close by setting FAB$V_DLT bit
490 $fh = VMS::Stdio::vmssysopen($path, $OPENFLAGS, 0600, 'fop=dlt');
493 my $flags = ( ($options{"unlink_on_close"} && !$KEEP_ALL) ?
496 $open_success = sysopen($fh, $path, $flags, 0600);
498 if ( $open_success ) {
500 # in case of odd umask force rw
503 # Opened successfully - return file handle and name
508 # Error opening file - abort with error
509 # if the reason was anything but EEXIST
510 unless ($!{EEXIST}) {
511 ${$options{ErrStr}} = "Could not create temp file $path: $!";
515 # Loop round for another try
518 } elsif ($options{"mkdir"}) {
520 # Open the temp directory
521 if (mkdir( $path, 0700)) {
522 # in case of odd umask
528 # Abort with error if the reason for failure was anything
530 unless ($!{EEXIST}) {
531 ${$options{ErrStr}} = "Could not create directory $path: $!";
535 # Loop round for another try
541 # Return true if the file can not be found
542 # Directory has been checked previously
544 return (undef, $path) unless -e $path;
546 # Try again until MAX_TRIES
550 # Did not successfully open the tempfile/dir
551 # so try again with a different set of random letters
552 # No point in trying to increment unless we have only
553 # 1 X say and the randomness could come up with the same
554 # file MAX_TRIES in a row.
556 # Store current attempt - in principal this implies that the
557 # 3rd time around the open attempt that the first temp file
558 # name could be generated again. Probably should store each
559 # attempt and make sure that none are repeated
561 my $original = $path;
562 my $counter = 0; # Stop infinite loop
567 # Generate new name from original template
568 $path = _replace_XX($template, $options{"suffixlen"});
572 } until ($path ne $original || $counter > $MAX_GUESS);
574 # Check for out of control looping
575 if ($counter > $MAX_GUESS) {
576 ${$options{ErrStr}} = "Tried to get a new temp name different to the previous value $MAX_GUESS times.\nSomething wrong with template?? ($template)";
582 # If we get here, we have run out of tries
583 ${ $options{ErrStr} } = "Have exceeded the maximum number of attempts ("
584 . MAX_TRIES . ") to open temp file/dir";
590 # Internal routine to return a random character from the
591 # character list. Does not do an srand() since rand()
592 # will do one automatically
594 # No arguments. Return value is the random character
596 # No longer called since _replace_XX runs a few percent faster if
597 # I inline the code. This is important if we are creating thousands of
602 $CHARS[ int( rand( $#CHARS ) ) ];
606 # Internal routine to replace the XXXX... with random characters
607 # This has to be done by _gettemp() every time it fails to
608 # open a temp file/dir
610 # Arguments: $template (the template with XXX),
611 # $ignore (number of characters at end to ignore)
613 # Returns: modified template
617 croak 'Usage: _replace_XX($template, $ignore)'
618 unless scalar(@_) == 2;
620 my ($path, $ignore) = @_;
622 # Do it as an if, since the suffix adjusts which section to replace
623 # and suffixlen=0 returns nothing if used in the substr directly
624 # Alternatively, could simply set $ignore to length($path)-1
625 # Don't want to always use substr when not required though.
628 substr($path, 0, - $ignore) =~ s/X(?=X*\z)/$CHARS[ int( rand( $#CHARS ) ) ]/ge;
630 $path =~ s/X(?=X*\z)/$CHARS[ int( rand( $#CHARS ) ) ]/ge;
635 # Internal routine to force a temp file to be writable after
636 # it is created so that we can unlink it. Windows seems to occassionally
637 # force a file to be readonly when written to certain temp locations
638 sub _force_writable {
644 # internal routine to check to see if the directory is safe
645 # First checks to see if the directory is not owned by the
646 # current user or root. Then checks to see if anyone else
647 # can write to the directory and if so, checks to see if
648 # it has the sticky bit set
650 # Will not work on systems that do not support sticky bit
652 #Args: directory path to check
653 # Optionally: reference to scalar to contain error message
654 # Returns true if the path is safe and false otherwise.
655 # Returns undef if can not even run stat() on the path
657 # This routine based on version written by Tom Christiansen
659 # Presumably, by the time we actually attempt to create the
660 # file or directory in this directory, it may not be safe
661 # anymore... Have to run _is_safe directly after the open.
669 my @info = stat($path);
670 unless (scalar(@info)) {
671 $$err_ref = "stat(path) returned no values";
674 return 1 if $^O eq 'VMS'; # owner delete control at file level
676 # Check to see whether owner is neither superuser (or a system uid) nor me
677 # Use the effective uid from the $> variable
679 if ($info[4] > File::Temp->top_system_uid() && $info[4] != $>) {
681 Carp::cluck(sprintf "uid=$info[4] topuid=%s euid=$< path='$path'",
682 File::Temp->top_system_uid());
684 $$err_ref = "Directory owned neither by root nor the current user"
689 # check whether group or other can write file
690 # use 066 to detect either reading or writing
691 # use 022 to check writability
692 # Do it with S_IWOTH and S_IWGRP for portability (maybe)
694 if (($info[2] & &Fcntl::S_IWGRP) || # Is group writable?
695 ($info[2] & &Fcntl::S_IWOTH) ) { # Is world writable?
696 # Must be a directory
698 $$err_ref = "Path ($path) is not a directory"
702 # Must have sticky bit set
704 $$err_ref = "Sticky bit not set on $path when dir is group|world writable"
713 # Internal routine to check whether a directory is safe
714 # for temp files. Safer than _is_safe since it checks for
715 # the possibility of chown giveaway and if that is a possibility
716 # checks each directory in the path to see if it is safe (with _is_safe)
718 # If _PC_CHOWN_RESTRICTED is not set, does the full test of each
721 # Takes optional second arg as scalar ref to error reason
725 # Need POSIX - but only want to bother if really necessary due to overhead
729 print "_is_verysafe testing $path\n" if $DEBUG;
730 return 1 if $^O eq 'VMS'; # owner delete control at file level
734 # Should Get the value of _PC_CHOWN_RESTRICTED if it is defined
735 # and If it is not there do the extensive test
736 my $chown_restricted;
737 $chown_restricted = &POSIX::_PC_CHOWN_RESTRICTED()
738 if eval { &POSIX::_PC_CHOWN_RESTRICTED(); 1};
740 # If chown_resticted is set to some value we should test it
741 if (defined $chown_restricted) {
743 # Return if the current directory is safe
744 return _is_safe($path,$err_ref) if POSIX::sysconf( $chown_restricted );
748 # To reach this point either, the _PC_CHOWN_RESTRICTED symbol
749 # was not avialable or the symbol was there but chown giveaway
750 # is allowed. Either way, we now have to test the entire tree for
753 # Convert path to an absolute directory if required
754 unless (File::Spec->file_name_is_absolute($path)) {
755 $path = File::Spec->rel2abs($path);
758 # Split directory into components - assume no file
759 my ($volume, $directories, undef) = File::Spec->splitpath( $path, 1);
761 # Slightly less efficient than having a function in File::Spec
762 # to chop off the end of a directory or even a function that
763 # can handle ../ in a directory tree
764 # Sometimes splitdir() returns a blank at the end
765 # so we will probably check the bottom directory twice in some cases
766 my @dirs = File::Spec->splitdir($directories);
768 # Concatenate one less directory each time around
769 foreach my $pos (0.. $#dirs) {
770 # Get a directory name
771 my $dir = File::Spec->catpath($volume,
772 File::Spec->catdir(@dirs[0.. $#dirs - $pos]),
776 print "TESTING DIR $dir\n" if $DEBUG;
778 # Check the directory
779 return 0 unless _is_safe($dir,$err_ref);
788 # internal routine to determine whether unlink works on this
789 # platform for files that are currently open.
790 # Returns true if we can, false otherwise.
792 # Currently WinNT, OS/2 and VMS can not unlink an opened file
793 # On VMS this is because the O_EXCL flag is used to open the
794 # temporary file. Currently I do not know enough about the issues
795 # on VMS to decide whether O_EXCL is a requirement.
797 sub _can_unlink_opened_file {
799 if ($^O eq 'MSWin32' || $^O eq 'os2' || $^O eq 'VMS' || $^O eq 'dos' || $^O eq 'MacOS') {
807 # internal routine to decide which security levels are allowed
808 # see safe_level() for more information on this
810 # Controls whether the supplied security level is allowed
812 # $cando = _can_do_level( $level )
819 # Always have to be able to do STANDARD
820 return 1 if $level == STANDARD;
822 # Currently, the systems that can do HIGH or MEDIUM are identical
823 if ( $^O eq 'MSWin32' || $^O eq 'os2' || $^O eq 'cygwin' || $^O eq 'dos' || $^O eq 'MacOS' || $^O eq 'mpeix') {
831 # This routine sets up a deferred unlinking of a specified
832 # filename and filehandle. It is used in the following cases:
833 # - Called by unlink0 if an opened file can not be unlinked
834 # - Called by tempfile() if files are to be removed on shutdown
835 # - Called by tempdir() if directories are to be removed on shutdown
838 # _deferred_unlink( $fh, $fname, $isdir );
840 # - filehandle (so that it can be expclicitly closed if open
841 # - filename (the thing we want to remove)
842 # - isdir (flag to indicate that we are being given a directory)
843 # [and hence no filehandle]
845 # Status is not referred to since all the magic is done with an END block
848 # Will set up two lexical variables to contain all the files to be
849 # removed. One array for files, another for directories They will
850 # only exist in this block.
852 # This means we only have to set up a single END block to remove
855 # in order to prevent child processes inadvertently deleting the parent
856 # temp files we use a hash to store the temp files and directories
857 # created by a particular process id.
859 # %files_to_unlink contains values that are references to an array of
860 # array references containing the filehandle and filename associated with
862 my (%files_to_unlink, %dirs_to_unlink);
864 # Set up an end block to use these arrays
869 # Cleanup function. Always triggered on END but can be invoked
874 my @files = (exists $files_to_unlink{$$} ?
875 @{ $files_to_unlink{$$} } : () );
876 foreach my $file (@files) {
877 # close the filehandle without checking its state
878 # in order to make real sure that this is closed
879 # if its already closed then I dont care about the answer
880 # probably a better way to do this
881 close($file->[0]); # file handle is [0]
883 if (-f $file->[1]) { # file name is [1]
884 _force_writable( $file->[1] ); # for windows
885 unlink $file->[1] or warn "Error removing ".$file->[1];
889 my @dirs = (exists $dirs_to_unlink{$$} ?
890 @{ $dirs_to_unlink{$$} } : () );
891 foreach my $dir (@dirs) {
893 rmtree($dir, $DEBUG, 0);
898 @{ $files_to_unlink{$$} } = ()
899 if exists $files_to_unlink{$$};
900 @{ $dirs_to_unlink{$$} } = ()
901 if exists $dirs_to_unlink{$$};
906 # This is the sub called to register a file for deferred unlinking
907 # This could simply store the input parameters and defer everything
908 # until the END block. For now we do a bit of checking at this
909 # point in order to make sure that (1) we have a file/dir to delete
910 # and (2) we have been called with the correct arguments.
911 sub _deferred_unlink {
913 croak 'Usage: _deferred_unlink($fh, $fname, $isdir)'
914 unless scalar(@_) == 3;
916 my ($fh, $fname, $isdir) = @_;
918 warn "Setting up deferred removal of $fname\n"
921 # If we have a directory, check that it is a directory
926 # Directory exists so store it
927 # first on VMS turn []foo into [.foo] for rmtree
928 $fname = VMS::Filespec::vmspath($fname) if $^O eq 'VMS';
929 $dirs_to_unlink{$$} = []
930 unless exists $dirs_to_unlink{$$};
931 push (@{ $dirs_to_unlink{$$} }, $fname);
934 carp "Request to remove directory $fname could not be completed since it does not exist!\n" if $^W;
941 # file exists so store handle and name for later removal
942 $files_to_unlink{$$} = []
943 unless exists $files_to_unlink{$$};
944 push(@{ $files_to_unlink{$$} }, [$fh, $fname]);
947 carp "Request to remove file $fname could not be completed since it is not there!\n" if $^W;
957 =head1 OBJECT-ORIENTED INTERFACE
959 This is the primary interface for interacting with
960 C<File::Temp>. Using the OO interface a temporary file can be created
961 when the object is constructed and the file can be removed when the
962 object is no longer required.
964 Note that there is no method to obtain the filehandle from the
965 C<File::Temp> object. The object itself acts as a filehandle. Also,
966 the object is configured such that it stringifies to the name of the
967 temporary file, and can be compared to a filename directly. The object
968 isa C<IO::Handle> and isa C<IO::Seekable> so all those methods are
975 Create a temporary file object.
977 my $tmp = new File::Temp();
979 by default the object is constructed as if C<tempfile>
980 was called without options, but with the additional behaviour
981 that the temporary file is removed by the object destructor
982 if UNLINK is set to true (the default).
984 Supported arguments are the same as for C<tempfile>: UNLINK
985 (defaulting to true), DIR and SUFFIX. Additionally, the filename
986 template is specified using the TEMPLATE option. The OPEN option
987 is not supported (the file is always opened).
989 $tmp = new File::Temp( TEMPLATE => 'tempXXXXX',
993 Arguments are case insensitive.
995 Can call croak() if an error occurs.
1001 my $class = ref($proto) || $proto;
1003 # read arguments and convert keys to upper case
1005 %args = map { uc($_), $args{$_} } keys %args;
1007 # see if they are unlinking (defaulting to yes)
1008 my $unlink = (exists $args{UNLINK} ? $args{UNLINK} : 1 );
1009 delete $args{UNLINK};
1011 # template (store it in an error so that it will
1012 # disappear from the arg list of tempfile
1013 my @template = ( exists $args{TEMPLATE} ? $args{TEMPLATE} : () );
1014 delete $args{TEMPLATE};
1019 # Open the file and retain file handle and file name
1020 my ($fh, $path) = tempfile( @template, %args );
1022 print "Tmp: $fh - $path\n" if $DEBUG;
1024 # Store the filename in the scalar slot
1027 # Store unlink information in hash slot (plus other constructor info)
1033 # final method-based configuration
1034 $fh->unlink_on_destroy( $unlink );
1041 Return the name of the temporary file associated with this object.
1043 $filename = $tmp->filename;
1045 This method is called automatically when the object is used as
1057 return $self->filename;
1060 =item B<unlink_on_destroy>
1062 Control whether the file is unlinked when the object goes out of scope.
1063 The file is removed if this value is true and $KEEP_ALL is not.
1065 $fh->unlink_on_destroy( 1 );
1067 Default is for the file to be removed.
1071 sub unlink_on_destroy {
1074 ${*$self}{UNLINK} = shift;
1076 return ${*$self}{UNLINK};
1081 When the object goes out of scope, the destructor is called. This
1082 destructor will attempt to unlink the file (using C<unlink1>)
1083 if the constructor was called with UNLINK set to 1 (the default state
1084 if UNLINK is not specified).
1086 No error is given if the unlink fails.
1088 If the global variable $KEEP_ALL is true, the file will not be removed.
1094 if (${*$self}{UNLINK} && !$KEEP_ALL) {
1095 print "# ---------> Unlinking $self\n" if $DEBUG;
1097 # The unlink1 may fail if the file has been closed
1098 # by the caller. This leaves us with the decision
1099 # of whether to refuse to remove the file or simply
1100 # do an unlink without test. Seems to be silly
1101 # to do this when we are trying to be careful
1103 _force_writable( $self->filename ); # for windows
1104 unlink1( $self, $self->filename )
1105 or unlink($self->filename);
1113 This section describes the recommended interface for generating
1114 temporary files and directories.
1120 This is the basic function to generate temporary files.
1121 The behaviour of the file can be changed using various options:
1124 ($fh, $filename) = tempfile();
1126 Create a temporary file in the directory specified for temporary
1127 files, as specified by the tmpdir() function in L<File::Spec>.
1129 ($fh, $filename) = tempfile($template);
1131 Create a temporary file in the current directory using the supplied
1132 template. Trailing `X' characters are replaced with random letters to
1133 generate the filename. At least four `X' characters must be present
1134 at the end of the template.
1136 ($fh, $filename) = tempfile($template, SUFFIX => $suffix)
1138 Same as previously, except that a suffix is added to the template
1139 after the `X' translation. Useful for ensuring that a temporary
1140 filename has a particular extension when needed by other applications.
1141 But see the WARNING at the end.
1143 ($fh, $filename) = tempfile($template, DIR => $dir);
1145 Translates the template as before except that a directory name
1148 ($fh, $filename) = tempfile($template, UNLINK => 1);
1150 Return the filename and filehandle as before except that the file is
1151 automatically removed when the program exits (dependent on
1152 $KEEP_ALL). Default is for the file to be removed if a file handle is
1153 requested and to be kept if the filename is requested. In a scalar
1154 context (where no filename is returned) the file is always deleted
1155 either (depending on the operating system) on exit or when it is
1156 closed (unless $KEEP_ALL is true when the temp file is created).
1158 Use the object-oriented interface if fine-grained control of when
1159 a file is removed is required.
1161 If the template is not specified, a template is always
1162 automatically generated. This temporary file is placed in tmpdir()
1163 (L<File::Spec>) unless a directory is specified explicitly with the
1166 $fh = tempfile( $template, DIR => $dir );
1168 If called in scalar context, only the filehandle is returned and the
1169 file will automatically be deleted when closed on operating systems
1170 that support this (see the description of tmpfile() elsewhere in this
1171 document). This is the preferred mode of operation, as if you only
1172 have a filehandle, you can never create a race condition by fumbling
1173 with the filename. On systems that can not unlink an open file or can
1174 not mark a file as temporary when it is opened (for example, Windows
1175 NT uses the C<O_TEMPORARY> flag) the file is marked for deletion when
1176 the program ends (equivalent to setting UNLINK to 1). The C<UNLINK>
1177 flag is ignored if present.
1179 (undef, $filename) = tempfile($template, OPEN => 0);
1181 This will return the filename based on the template but
1182 will not open this file. Cannot be used in conjunction with
1183 UNLINK set to true. Default is to always open the file
1184 to protect from possible race conditions. A warning is issued
1185 if warnings are turned on. Consider using the tmpnam()
1186 and mktemp() functions described elsewhere in this document
1187 if opening the file is not required.
1189 Options can be combined as required.
1191 Will croak() if there is an error.
1197 # Can not check for argument count since we can have any
1202 "DIR" => undef, # Directory prefix
1203 "SUFFIX" => '', # Template suffix
1204 "UNLINK" => 0, # Do not unlink file on exit
1205 "OPEN" => 1, # Open file
1208 # Check to see whether we have an odd or even number of arguments
1209 my $template = (scalar(@_) % 2 == 1 ? shift(@_) : undef);
1211 # Read the options and merge with defaults
1212 %options = (%options, @_) if @_;
1214 # First decision is whether or not to open the file
1215 if (! $options{"OPEN"}) {
1217 warn "tempfile(): temporary filename requested but not opened.\nPossibly unsafe, consider using tempfile() with OPEN set to true\n"
1222 if ($options{"DIR"} and $^O eq 'VMS') {
1224 # on VMS turn []foo into [.foo] for concatenation
1225 $options{"DIR"} = VMS::Filespec::vmspath($options{"DIR"});
1228 # Construct the template
1230 # Have a choice of trying to work around the mkstemp/mktemp/tmpnam etc
1231 # functions or simply constructing a template and using _gettemp()
1232 # explicitly. Go for the latter
1234 # First generate a template if not defined and prefix the directory
1235 # If no template must prefix the temp directory
1236 if (defined $template) {
1237 if ($options{"DIR"}) {
1239 $template = File::Spec->catfile($options{"DIR"}, $template);
1245 if ($options{"DIR"}) {
1247 $template = File::Spec->catfile($options{"DIR"}, TEMPXXX);
1251 $template = File::Spec->catfile(File::Spec->tmpdir, TEMPXXX);
1258 $template .= $options{"SUFFIX"};
1260 # Determine whether we should tell _gettemp to unlink the file
1261 # On unix this is irrelevant and can be worked out after the file is
1262 # opened (simply by unlinking the open filehandle). On Windows or VMS
1263 # we have to indicate temporary-ness when we open the file. In general
1264 # we only want a true temporary file if we are returning just the
1265 # filehandle - if the user wants the filename they probably do not
1266 # want the file to disappear as soon as they close it (which may be
1267 # important if they want a child process to use the file)
1268 # For this reason, tie unlink_on_close to the return context regardless
1270 my $unlink_on_close = ( wantarray ? 0 : 1);
1273 my ($fh, $path, $errstr);
1274 croak "Error in tempfile() using $template: $errstr"
1275 unless (($fh, $path) = _gettemp($template,
1276 "open" => $options{'OPEN'},
1278 "unlink_on_close" => $unlink_on_close,
1279 "suffixlen" => length($options{'SUFFIX'}),
1280 "ErrStr" => \$errstr,
1283 # Set up an exit handler that can do whatever is right for the
1284 # system. This removes files at exit when requested explicitly or when
1285 # system is asked to unlink_on_close but is unable to do so because
1286 # of OS limitations.
1287 # The latter should be achieved by using a tied filehandle.
1288 # Do not check return status since this is all done with END blocks.
1289 _deferred_unlink($fh, $path, 0) if $options{"UNLINK"};
1294 if ($options{'OPEN'}) {
1295 return ($fh, $path);
1297 return (undef, $path);
1302 # Unlink the file. It is up to unlink0 to decide what to do with
1303 # this (whether to unlink now or to defer until later)
1304 unlink0($fh, $path) or croak "Error unlinking file $path using unlink0";
1306 # Return just the filehandle.
1315 This is the recommended interface for creation of temporary directories.
1316 The behaviour of the function depends on the arguments:
1318 $tempdir = tempdir();
1320 Create a directory in tmpdir() (see L<File::Spec|File::Spec>).
1322 $tempdir = tempdir( $template );
1324 Create a directory from the supplied template. This template is
1325 similar to that described for tempfile(). `X' characters at the end
1326 of the template are replaced with random letters to construct the
1327 directory name. At least four `X' characters must be in the template.
1329 $tempdir = tempdir ( DIR => $dir );
1331 Specifies the directory to use for the temporary directory.
1332 The temporary directory name is derived from an internal template.
1334 $tempdir = tempdir ( $template, DIR => $dir );
1336 Prepend the supplied directory name to the template. The template
1337 should not include parent directory specifications itself. Any parent
1338 directory specifications are removed from the template before
1339 prepending the supplied directory.
1341 $tempdir = tempdir ( $template, TMPDIR => 1 );
1343 Using the supplied template, create the temporary directory in
1344 a standard location for temporary files. Equivalent to doing
1346 $tempdir = tempdir ( $template, DIR => File::Spec->tmpdir);
1348 but shorter. Parent directory specifications are stripped from the
1349 template itself. The C<TMPDIR> option is ignored if C<DIR> is set
1350 explicitly. Additionally, C<TMPDIR> is implied if neither a template
1351 nor a directory are supplied.
1353 $tempdir = tempdir( $template, CLEANUP => 1);
1355 Create a temporary directory using the supplied template, but
1356 attempt to remove it (and all files inside it) when the program
1357 exits. Note that an attempt will be made to remove all files from
1358 the directory even if they were not created by this module (otherwise
1359 why ask to clean it up?). The directory removal is made with
1360 the rmtree() function from the L<File::Path|File::Path> module.
1361 Of course, if the template is not specified, the temporary directory
1362 will be created in tmpdir() and will also be removed at program exit.
1364 Will croak() if there is an error.
1372 # Can not check for argument count since we can have any
1377 "CLEANUP" => 0, # Remove directory on exit
1378 "DIR" => '', # Root directory
1379 "TMPDIR" => 0, # Use tempdir with template
1382 # Check to see whether we have an odd or even number of arguments
1383 my $template = (scalar(@_) % 2 == 1 ? shift(@_) : undef );
1385 # Read the options and merge with defaults
1386 %options = (%options, @_) if @_;
1388 # Modify or generate the template
1390 # Deal with the DIR and TMPDIR options
1391 if (defined $template) {
1393 # Need to strip directory path if using DIR or TMPDIR
1394 if ($options{'TMPDIR'} || $options{'DIR'}) {
1396 # Strip parent directory from the filename
1398 # There is no filename at the end
1399 $template = VMS::Filespec::vmspath($template) if $^O eq 'VMS';
1400 my ($volume, $directories, undef) = File::Spec->splitpath( $template, 1);
1402 # Last directory is then our template
1403 $template = (File::Spec->splitdir($directories))[-1];
1405 # Prepend the supplied directory or temp dir
1406 if ($options{"DIR"}) {
1408 $template = File::Spec->catdir($options{"DIR"}, $template);
1410 } elsif ($options{TMPDIR}) {
1413 $template = File::Spec->catdir(File::Spec->tmpdir, $template);
1421 if ($options{"DIR"}) {
1423 $template = File::Spec->catdir($options{"DIR"}, TEMPXXX);
1427 $template = File::Spec->catdir(File::Spec->tmpdir, TEMPXXX);
1433 # Create the directory
1436 if ($^O eq 'VMS') { # dir names can end in delimiters
1437 $template =~ m/([\.\]:>]+)$/;
1438 $suffixlen = length($1);
1440 if ( ($^O eq 'MacOS') && (substr($template, -1) eq ':') ) {
1441 # dir name has a trailing ':'
1446 croak "Error in tempdir() using $template: $errstr"
1447 unless ((undef, $tempdir) = _gettemp($template,
1450 "suffixlen" => $suffixlen,
1451 "ErrStr" => \$errstr,
1454 # Install exit handler; must be dynamic to get lexical
1455 if ( $options{'CLEANUP'} && -d $tempdir) {
1456 _deferred_unlink(undef, $tempdir, 1);
1459 # Return the dir name
1466 =head1 MKTEMP FUNCTIONS
1468 The following functions are Perl implementations of the
1469 mktemp() family of temp file generation system calls.
1475 Given a template, returns a filehandle to the temporary file and the name
1478 ($fh, $name) = mkstemp( $template );
1480 In scalar context, just the filehandle is returned.
1482 The template may be any filename with some number of X's appended
1483 to it, for example F</tmp/temp.XXXX>. The trailing X's are replaced
1484 with unique alphanumeric combinations.
1486 Will croak() if there is an error.
1494 croak "Usage: mkstemp(template)"
1497 my $template = shift;
1499 my ($fh, $path, $errstr);
1500 croak "Error in mkstemp using $template: $errstr"
1501 unless (($fh, $path) = _gettemp($template,
1505 "ErrStr" => \$errstr,
1509 return ($fh, $path);
1519 Similar to mkstemp(), except that an extra argument can be supplied
1520 with a suffix to be appended to the template.
1522 ($fh, $name) = mkstemps( $template, $suffix );
1524 For example a template of C<testXXXXXX> and suffix of C<.dat>
1525 would generate a file similar to F<testhGji_w.dat>.
1527 Returns just the filehandle alone when called in scalar context.
1529 Will croak() if there is an error.
1535 croak "Usage: mkstemps(template, suffix)"
1539 my $template = shift;
1542 $template .= $suffix;
1544 my ($fh, $path, $errstr);
1545 croak "Error in mkstemps using $template: $errstr"
1546 unless (($fh, $path) = _gettemp($template,
1549 "suffixlen" => length($suffix),
1550 "ErrStr" => \$errstr,
1554 return ($fh, $path);
1563 Create a directory from a template. The template must end in
1564 X's that are replaced by the routine.
1566 $tmpdir_name = mkdtemp($template);
1568 Returns the name of the temporary directory created.
1570 Directory must be removed by the caller.
1572 Will croak() if there is an error.
1580 croak "Usage: mkdtemp(template)"
1583 my $template = shift;
1585 if ($^O eq 'VMS') { # dir names can end in delimiters
1586 $template =~ m/([\.\]:>]+)$/;
1587 $suffixlen = length($1);
1589 if ( ($^O eq 'MacOS') && (substr($template, -1) eq ':') ) {
1590 # dir name has a trailing ':'
1593 my ($junk, $tmpdir, $errstr);
1594 croak "Error creating temp directory from template $template\: $errstr"
1595 unless (($junk, $tmpdir) = _gettemp($template,
1598 "suffixlen" => $suffixlen,
1599 "ErrStr" => \$errstr,
1608 Returns a valid temporary filename but does not guarantee
1609 that the file will not be opened by someone else.
1611 $unopened_file = mktemp($template);
1613 Template is the same as that required by mkstemp().
1615 Will croak() if there is an error.
1621 croak "Usage: mktemp(template)"
1624 my $template = shift;
1626 my ($tmpname, $junk, $errstr);
1627 croak "Error getting name to temp file from template $template: $errstr"
1628 unless (($junk, $tmpname) = _gettemp($template,
1632 "ErrStr" => \$errstr,
1640 =head1 POSIX FUNCTIONS
1642 This section describes the re-implementation of the tmpnam()
1643 and tmpfile() functions described in L<POSIX>
1644 using the mkstemp() from this module.
1646 Unlike the L<POSIX|POSIX> implementations, the directory used
1647 for the temporary file is not specified in a system include
1648 file (C<P_tmpdir>) but simply depends on the choice of tmpdir()
1649 returned by L<File::Spec|File::Spec>. On some implementations this
1650 location can be set using the C<TMPDIR> environment variable, which
1652 If this is a problem, simply use mkstemp() and specify a template.
1658 When called in scalar context, returns the full name (including path)
1659 of a temporary file (uses mktemp()). The only check is that the file does
1660 not already exist, but there is no guarantee that that condition will
1665 When called in list context, a filehandle to the open file and
1666 a filename are returned. This is achieved by calling mkstemp()
1667 after constructing a suitable template.
1669 ($fh, $file) = tmpnam();
1671 If possible, this form should be used to prevent possible
1674 See L<File::Spec/tmpdir> for information on the choice of temporary
1675 directory for a particular operating system.
1677 Will croak() if there is an error.
1683 # Retrieve the temporary directory name
1684 my $tmpdir = File::Spec->tmpdir;
1686 croak "Error temporary directory is not writable"
1689 # Use a ten character template and append to tmpdir
1690 my $template = File::Spec->catfile($tmpdir, TEMPXXX);
1693 return mkstemp($template);
1695 return mktemp($template);
1702 Returns the filehandle of a temporary file.
1706 The file is removed when the filehandle is closed or when the program
1707 exits. No access to the filename is provided.
1709 If the temporary file can not be created undef is returned.
1710 Currently this command will probably not work when the temporary
1711 directory is on an NFS file system.
1713 Will croak() if there is an error.
1719 # Simply call tmpnam() in a list context
1720 my ($fh, $file) = tmpnam();
1722 # Make sure file is removed when filehandle is closed
1723 # This will fail on NFS
1733 =head1 ADDITIONAL FUNCTIONS
1735 These functions are provided for backwards compatibility
1736 with common tempfile generation C library functions.
1738 They are not exported and must be addressed using the full package
1745 Return the name of a temporary file in the specified directory
1746 using a prefix. The file is guaranteed not to exist at the time
1747 the function was called, but such guarantees are good for one
1748 clock tick only. Always use the proper form of C<sysopen>
1749 with C<O_CREAT | O_EXCL> if you must open such a filename.
1751 $filename = File::Temp::tempnam( $dir, $prefix );
1753 Equivalent to running mktemp() with $dir/$prefixXXXXXXXX
1754 (using unix file convention as an example)
1756 Because this function uses mktemp(), it can suffer from race conditions.
1758 Will croak() if there is an error.
1764 croak 'Usage tempnam($dir, $prefix)' unless scalar(@_) == 2;
1766 my ($dir, $prefix) = @_;
1768 # Add a string to the prefix
1769 $prefix .= 'XXXXXXXX';
1771 # Concatenate the directory to the file
1772 my $template = File::Spec->catfile($dir, $prefix);
1774 return mktemp($template);
1780 =head1 UTILITY FUNCTIONS
1782 Useful functions for dealing with the filehandle and filename.
1788 Given an open filehandle and the associated filename, make a safe
1789 unlink. This is achieved by first checking that the filename and
1790 filehandle initially point to the same file and that the number of
1791 links to the file is 1 (all fields returned by stat() are compared).
1792 Then the filename is unlinked and the filehandle checked once again to
1793 verify that the number of links on that file is now 0. This is the
1794 closest you can come to making sure that the filename unlinked was the
1795 same as the file whose descriptor you hold.
1798 or die "Error unlinking file $path safely";
1800 Returns false on error but croaks() if there is a security
1801 anomaly. The filehandle is not closed since on some occasions this is
1804 On some platforms, for example Windows NT, it is not possible to
1805 unlink an open file (the file must be closed first). On those
1806 platforms, the actual unlinking is deferred until the program ends and
1807 good status is returned. A check is still performed to make sure that
1808 the filehandle and filename are pointing to the same thing (but not at
1809 the time the end block is executed since the deferred removal may not
1810 have access to the filehandle).
1812 Additionally, on Windows NT not all the fields returned by stat() can
1813 be compared. For example, the C<dev> and C<rdev> fields seem to be
1814 different. Also, it seems that the size of the file returned by stat()
1815 does not always agree, with C<stat(FH)> being more accurate than
1816 C<stat(filename)>, presumably because of caching issues even when
1817 using autoflush (this is usually overcome by waiting a while after
1818 writing to the tempfile before attempting to C<unlink0> it).
1820 Finally, on NFS file systems the link count of the file handle does
1821 not always go to zero immediately after unlinking. Currently, this
1822 command is expected to fail on NFS disks.
1824 This function is disabled if the global variable $KEEP_ALL is true
1825 and an unlink on open file is supported. If the unlink is to be deferred
1826 to the END block, the file is still registered for removal.
1828 This function should not be called if you are using the object oriented
1829 interface since the it will interfere with the object destructor deleting
1836 croak 'Usage: unlink0(filehandle, filename)'
1837 unless scalar(@_) == 2;
1840 my ($fh, $path) = @_;
1842 cmpstat($fh, $path) or return 0;
1844 # attempt remove the file (does not work on some platforms)
1845 if (_can_unlink_opened_file()) {
1847 # return early (Without unlink) if we have been instructed to retain files.
1848 return 1 if $KEEP_ALL;
1850 # XXX: do *not* call this on a directory; possible race
1851 # resulting in recursive removal
1852 croak "unlink0: $path has become a directory!" if -d $path;
1853 unlink($path) or return 0;
1855 # Stat the filehandle
1858 print "Link count = $fh[3] \n" if $DEBUG;
1860 # Make sure that the link count is zero
1861 # - Cygwin provides deferred unlinking, however,
1862 # on Win9x the link count remains 1
1863 # On NFS the link count may still be 1 but we cant know that
1865 return ( $fh[3] == 0 or $^O eq 'cygwin' ? 1 : 0);
1868 _deferred_unlink($fh, $path, 0);
1876 Compare C<stat> of filehandle with C<stat> of provided filename. This
1877 can be used to check that the filename and filehandle initially point
1878 to the same file and that the number of links to the file is 1 (all
1879 fields returned by stat() are compared).
1882 or die "Error comparing handle with file";
1884 Returns false if the stat information differs or if the link count is
1885 greater than 1. Calls croak if there is a security anomaly.
1887 On certain platforms, for example Windows, not all the fields returned by stat()
1888 can be compared. For example, the C<dev> and C<rdev> fields seem to be
1889 different in Windows. Also, it seems that the size of the file
1890 returned by stat() does not always agree, with C<stat(FH)> being more
1891 accurate than C<stat(filename)>, presumably because of caching issues
1892 even when using autoflush (this is usually overcome by waiting a while
1893 after writing to the tempfile before attempting to C<unlink0> it).
1895 Not exported by default.
1901 croak 'Usage: cmpstat(filehandle, filename)'
1902 unless scalar(@_) == 2;
1905 my ($fh, $path) = @_;
1907 warn "Comparing stat\n"
1910 # Stat the filehandle - which may be closed if someone has manually
1911 # closed the file. Can not turn off warnings without using $^W
1912 # unless we upgrade to 5.006 minimum requirement
1920 if ($fh[3] > 1 && $^W) {
1921 carp "unlink0: fstat found too many links; SB=@fh" if $^W;
1925 my @path = stat $path;
1928 carp "unlink0: $path is gone already" if $^W;
1932 # this is no longer a file, but may be a directory, or worse
1934 confess "panic: $path is no longer a file: SB=@fh";
1937 # Do comparison of each member of the array
1938 # On WinNT dev and rdev seem to be different
1939 # depending on whether it is a file or a handle.
1940 # Cannot simply compare all members of the stat return
1941 # Select the ones we can use
1942 my @okstat = (0..$#fh); # Use all by default
1943 if ($^O eq 'MSWin32') {
1944 @okstat = (1,2,3,4,5,7,8,9,10);
1945 } elsif ($^O eq 'os2') {
1946 @okstat = (0, 2..$#fh);
1947 } elsif ($^O eq 'VMS') { # device and file ID are sufficient
1949 } elsif ($^O eq 'dos') {
1950 @okstat = (0,2..7,11..$#fh);
1951 } elsif ($^O eq 'mpeix') {
1952 @okstat = (0..4,8..10);
1955 # Now compare each entry explicitly by number
1957 print "Comparing: $_ : $fh[$_] and $path[$_]\n" if $DEBUG;
1958 # Use eq rather than == since rdev, blksize, and blocks (6, 11,
1959 # and 12) will be '' on platforms that do not support them. This
1960 # is fine since we are only comparing integers.
1961 unless ($fh[$_] eq $path[$_]) {
1962 warn "Did not match $_ element of stat\n" if $DEBUG;
1972 Similar to C<unlink0> except after file comparison using cmpstat, the
1973 filehandle is closed prior to attempting to unlink the file. This
1974 allows the file to be removed without using an END block, but does
1975 mean that the post-unlink comparison of the filehandle state provided
1976 by C<unlink0> is not available.
1979 or die "Error closing and unlinking file";
1981 Usually called from the object destructor when using the OO interface.
1983 Not exported by default.
1985 This function is disabled if the global variable $KEEP_ALL is true.
1987 Can call croak() if there is a security anomaly during the stat()
1993 croak 'Usage: unlink1(filehandle, filename)'
1994 unless scalar(@_) == 2;
1997 my ($fh, $path) = @_;
1999 cmpstat($fh, $path) or return 0;
2002 close( $fh ) or return 0;
2004 # Make sure the file is writable (for windows)
2005 _force_writable( $path );
2007 # return early (without unlink) if we have been instructed to retain files.
2008 return 1 if $KEEP_ALL;
2011 return unlink($path);
2016 Calling this function will cause any temp files or temp directories
2017 that are registered for removal to be removed. This happens automatically
2018 when the process exits but can be triggered manually if the caller is sure
2019 that none of the temp files are required. This method can be registered as
2022 On OSes where temp files are automatically removed when the temp file
2023 is closed, calling this function will have no effect other than to remove
2024 temporary directories (which may include temporary files).
2026 File::Temp::cleanup();
2028 Not exported by default.
2032 =head1 PACKAGE VARIABLES
2034 These functions control the global state of the package.
2040 Controls the lengths to which the module will go to check the safety of the
2041 temporary file or directory before proceeding.
2048 Do the basic security measures to ensure the directory exists and
2049 is writable, that the umask() is fixed before opening of the file,
2050 that temporary files are opened only if they do not already exist, and
2051 that possible race conditions are avoided. Finally the L<unlink0|"unlink0">
2052 function is used to remove files safely.
2056 In addition to the STANDARD security, the output directory is checked
2057 to make sure that it is owned either by root or the user running the
2058 program. If the directory is writable by group or by other, it is then
2059 checked to make sure that the sticky bit is set.
2061 Will not work on platforms that do not support the C<-k> test
2066 In addition to the MEDIUM security checks, also check for the
2067 possibility of ``chown() giveaway'' using the L<POSIX|POSIX>
2068 sysconf() function. If this is a possibility, each directory in the
2069 path is checked in turn for safeness, recursively walking back to the
2072 For platforms that do not support the L<POSIX|POSIX>
2073 C<_PC_CHOWN_RESTRICTED> symbol (for example, Windows NT) it is
2074 assumed that ``chown() giveaway'' is possible and the recursive test
2079 The level can be changed as follows:
2081 File::Temp->safe_level( File::Temp::HIGH );
2083 The level constants are not exported by the module.
2085 Currently, you must be running at least perl v5.6.0 in order to
2086 run with MEDIUM or HIGH security. This is simply because the
2087 safety tests use functions from L<Fcntl|Fcntl> that are not
2088 available in older versions of perl. The problem is that the version
2089 number for Fcntl is the same in perl 5.6.0 and in 5.005_03 even though
2090 they are different versions.
2092 On systems that do not support the HIGH or MEDIUM safety levels
2093 (for example Win NT or OS/2) any attempt to change the level will
2094 be ignored. The decision to ignore rather than raise an exception
2095 allows portable programs to be written with high security in mind
2096 for the systems that can support this without those programs failing
2097 on systems where the extra tests are irrelevant.
2099 If you really need to see whether the change has been accepted
2100 simply examine the return value of C<safe_level>.
2102 $newlevel = File::Temp->safe_level( File::Temp::HIGH );
2103 die "Could not change to high security"
2104 if $newlevel != File::Temp::HIGH;
2109 # protect from using the variable itself
2110 my $LEVEL = STANDARD;
2115 if (($level != STANDARD) && ($level != MEDIUM) && ($level != HIGH)) {
2116 carp "safe_level: Specified level ($level) not STANDARD, MEDIUM or HIGH - ignoring\n" if $^W;
2118 # Dont allow this on perl 5.005 or earlier
2119 if ($] < 5.006 && $level != STANDARD) {
2120 # Cant do MEDIUM or HIGH checks
2121 croak "Currently requires perl 5.006 or newer to do the safe checks";
2123 # Check that we are allowed to change level
2124 # Silently ignore if we can not.
2125 $LEVEL = $level if _can_do_level($level);
2134 This is the highest UID on the current system that refers to a root
2135 UID. This is used to make sure that the temporary directory is
2136 owned by a system UID (C<root>, C<bin>, C<sys> etc) rather than
2139 This is required since on many unix systems C</tmp> is not owned
2142 Default is to assume that any UID less than or equal to 10 is a root
2145 File::Temp->top_system_uid(10);
2146 my $topid = File::Temp->top_system_uid;
2148 This value can be adjusted to reduce security checking if required.
2149 The value is only relevant when C<safe_level> is set to MEDIUM or higher.
2154 my $TopSystemUID = 10;
2155 $TopSystemUID = 197108 if $^O eq 'interix'; # "Administrator"
2156 sub top_system_uid {
2160 croak "top_system_uid: UIDs should be numeric"
2161 unless $newuid =~ /^\d+$/s;
2162 $TopSystemUID = $newuid;
2164 return $TopSystemUID;
2170 Controls whether temporary files and directories should be retained
2171 regardless of any instructions in the program to remove them
2172 automatically. This is useful for debugging but should not be used in
2175 $File::Temp::KEEP_ALL = 1;
2177 Default is for files to be removed as requested by the caller.
2179 In some cases, files will only be retained if this variable is true
2180 when the file is created. This means that you can not create a temporary
2181 file, set this variable and expect the temp file to still be around
2182 when the program exits.
2186 Controls whether debugging messages should be enabled.
2188 $File::Temp::DEBUG = 1;
2190 Default is for debugging mode to be disabled.
2196 For maximum security, endeavour always to avoid ever looking at,
2197 touching, or even imputing the existence of the filename. You do not
2198 know that that filename is connected to the same file as the handle
2199 you have, and attempts to check this can only trigger more race
2200 conditions. It's far more secure to use the filehandle alone and
2201 dispense with the filename altogether.
2203 If you need to pass the handle to something that expects a filename
2204 then, on a unix system, use C<"/dev/fd/" . fileno($fh)> for arbitrary
2205 programs, or more generally C<< "+<=&" . fileno($fh) >> for Perl
2206 programs. You will have to clear the close-on-exec bit on that file
2207 descriptor before passing it to another process.
2209 use Fcntl qw/F_SETFD F_GETFD/;
2210 fcntl($tmpfh, F_SETFD, 0)
2211 or die "Can't clear close-on-exec flag on temp fh: $!\n";
2213 =head2 Temporary files and NFS
2215 Some problems are associated with using temporary files that reside
2216 on NFS file systems and it is recommended that a local filesystem
2217 is used whenever possible. Some of the security tests will most probably
2218 fail when the temp file is not local. Additionally, be aware that
2219 the performance of I/O operations over NFS will not be as good as for
2224 In some cases files created by File::Temp are removed from within an
2225 END block. Since END blocks are triggered when a child process exits
2226 (unless C<POSIX::_exit()> is used by the child) File::Temp takes care
2227 to only remove those temp files created by a particular process ID. This
2228 means that a child will not attempt to remove temp files created by the
2231 If you are forking many processes in parallel that are all creating
2232 temporary files, you may need to reset the random number seed using
2233 srand(EXPR) in each child else all the children will attempt to walk
2234 through the same set of random file names and may well cause
2235 themselves to give up if they exceed the number of retry attempts.
2239 The file returned by File::Temp will have been opened in binary mode
2240 if such a mode is available. If that is not correct, use the binmode()
2241 function to change the mode of the filehandle.
2245 Originally began life in May 1999 as an XS interface to the system
2246 mkstemp() function. In March 2000, the OpenBSD mkstemp() code was
2247 translated to Perl for total control of the code's
2248 security checking, to ensure the presence of the function regardless of
2249 operating system and to help with portability. The module was shipped
2250 as a standard part of perl from v5.6.1.
2254 L<POSIX/tmpnam>, L<POSIX/tmpfile>, L<File::Spec>, L<File::Path>
2256 See L<IO::File> and L<File::MkTemp>, L<Apache::TempFile> for
2257 different implementations of temporary file handling.
2261 Tim Jenness E<lt>tjenness@cpan.orgE<gt>
2263 Copyright (C) 1999-2007 Tim Jenness and the UK Particle Physics and
2264 Astronomy Research Council. All Rights Reserved. This program is free
2265 software; you can redistribute it and/or modify it under the same
2266 terms as Perl itself.
2268 Original Perl implementation loosely based on the OpenBSD C code for
2269 mkstemp(). Thanks to Tom Christiansen for suggesting that this module
2270 should be written and providing ideas for code improvements and
2271 security enhancements.