| 1 | package File::Temp; |
| 2 | |
| 3 | =head1 NAME |
| 4 | |
| 5 | File::Temp - return name and handle of a temporary file safely |
| 6 | |
| 7 | =begin __INTERNALS |
| 8 | |
| 9 | =head1 PORTABILITY |
| 10 | |
| 11 | This module is designed to be portable across operating systems |
| 12 | and it currently supports Unix, VMS, DOS, OS/2, Windows and |
| 13 | Mac OS (Classic). When |
| 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 | |
| 21 | Can the OS unlink an open file? If it can not then the |
| 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 | |
| 42 | =head1 SYNOPSIS |
| 43 | |
| 44 | use File::Temp qw/ tempfile tempdir /; |
| 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 | $fh = tempfile(); |
| 53 | |
| 54 | MkTemp family: |
| 55 | |
| 56 | use File::Temp qw/ :mktemp /; |
| 57 | |
| 58 | ($fh, $file) = mkstemp( "tmpfileXXXXX" ); |
| 59 | ($fh, $file) = mkstemps( "tmpfileXXXXXX", $suffix); |
| 60 | |
| 61 | $tmpdir = mkdtemp( $template ); |
| 62 | |
| 63 | $unopened_file = mktemp( $template ); |
| 64 | |
| 65 | POSIX functions: |
| 66 | |
| 67 | use File::Temp qw/ :POSIX /; |
| 68 | |
| 69 | $file = tmpnam(); |
| 70 | $fh = tmpfile(); |
| 71 | |
| 72 | ($fh, $file) = tmpnam(); |
| 73 | ($fh, $file) = tmpfile(); |
| 74 | |
| 75 | |
| 76 | Compatibility functions: |
| 77 | |
| 78 | $unopened_file = File::Temp::tempnam( $dir, $pfx ); |
| 79 | |
| 80 | =begin later |
| 81 | |
| 82 | Objects (NOT YET IMPLEMENTED): |
| 83 | |
| 84 | require File::Temp; |
| 85 | |
| 86 | $fh = new File::Temp($template); |
| 87 | $fname = $fh->filename; |
| 88 | |
| 89 | =end later |
| 90 | |
| 91 | =head1 DESCRIPTION |
| 92 | |
| 93 | C<File::Temp> can be used to create and open temporary files in a safe way. |
| 94 | The tempfile() function can be used to return the name and the open |
| 95 | filehandle of a temporary file. The tempdir() function can |
| 96 | be used to create a temporary directory. |
| 97 | |
| 98 | The security aspect of temporary file creation is emphasized such that |
| 99 | a filehandle and filename are returned together. This helps guarantee |
| 100 | that a race condition can not occur where the temporary file is |
| 101 | created by another process between checking for the existence of the |
| 102 | file and its opening. Additional security levels are provided to |
| 103 | check, for example, that the sticky bit is set on world writable |
| 104 | directories. See L<"safe_level"> for more information. |
| 105 | |
| 106 | For compatibility with popular C library functions, Perl implementations of |
| 107 | the mkstemp() family of functions are provided. These are, mkstemp(), |
| 108 | mkstemps(), mkdtemp() and mktemp(). |
| 109 | |
| 110 | Additionally, implementations of the standard L<POSIX|POSIX> |
| 111 | tmpnam() and tmpfile() functions are provided if required. |
| 112 | |
| 113 | Implementations of mktemp(), tmpnam(), and tempnam() are provided, |
| 114 | but should be used with caution since they return only a filename |
| 115 | that was valid when function was called, so cannot guarantee |
| 116 | that the file will not exist by the time the caller opens the filename. |
| 117 | |
| 118 | =cut |
| 119 | |
| 120 | # 5.6.0 gives us S_IWOTH, S_IWGRP, our and auto-vivifying filehandls |
| 121 | # People would like a version on 5.005 so give them what they want :-) |
| 122 | use 5.005; |
| 123 | use strict; |
| 124 | use Carp; |
| 125 | use File::Spec 0.8; |
| 126 | use File::Path qw/ rmtree /; |
| 127 | use Fcntl 1.03; |
| 128 | use Errno; |
| 129 | require VMS::Stdio if $^O eq 'VMS'; |
| 130 | |
| 131 | # Need the Symbol package if we are running older perl |
| 132 | require Symbol if $] < 5.006; |
| 133 | |
| 134 | |
| 135 | # use 'our' on v5.6.0 |
| 136 | use vars qw($VERSION @EXPORT_OK %EXPORT_TAGS $DEBUG); |
| 137 | |
| 138 | $DEBUG = 0; |
| 139 | |
| 140 | # We are exporting functions |
| 141 | |
| 142 | use base qw/Exporter/; |
| 143 | |
| 144 | # Export list - to allow fine tuning of export table |
| 145 | |
| 146 | @EXPORT_OK = qw{ |
| 147 | tempfile |
| 148 | tempdir |
| 149 | tmpnam |
| 150 | tmpfile |
| 151 | mktemp |
| 152 | mkstemp |
| 153 | mkstemps |
| 154 | mkdtemp |
| 155 | unlink0 |
| 156 | }; |
| 157 | |
| 158 | # Groups of functions for export |
| 159 | |
| 160 | %EXPORT_TAGS = ( |
| 161 | 'POSIX' => [qw/ tmpnam tmpfile /], |
| 162 | 'mktemp' => [qw/ mktemp mkstemp mkstemps mkdtemp/], |
| 163 | ); |
| 164 | |
| 165 | # add contents of these tags to @EXPORT |
| 166 | Exporter::export_tags('POSIX','mktemp'); |
| 167 | |
| 168 | # Version number |
| 169 | |
| 170 | $VERSION = '0.13'; |
| 171 | |
| 172 | # This is a list of characters that can be used in random filenames |
| 173 | |
| 174 | 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 |
| 175 | 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 |
| 176 | 0 1 2 3 4 5 6 7 8 9 _ |
| 177 | /); |
| 178 | |
| 179 | # Maximum number of tries to make a temp file before failing |
| 180 | |
| 181 | use constant MAX_TRIES => 10; |
| 182 | |
| 183 | # Minimum number of X characters that should be in a template |
| 184 | use constant MINX => 4; |
| 185 | |
| 186 | # Default template when no template supplied |
| 187 | |
| 188 | use constant TEMPXXX => 'X' x 10; |
| 189 | |
| 190 | # Constants for the security level |
| 191 | |
| 192 | use constant STANDARD => 0; |
| 193 | use constant MEDIUM => 1; |
| 194 | use constant HIGH => 2; |
| 195 | |
| 196 | # OPENFLAGS. If we defined the flag to use with Sysopen here this gives |
| 197 | # us an optimisation when many temporary files are requested |
| 198 | |
| 199 | my $OPENFLAGS = O_CREAT | O_EXCL | O_RDWR; |
| 200 | |
| 201 | unless ($^O eq 'MacOS') { |
| 202 | for my $oflag (qw/ FOLLOW BINARY LARGEFILE EXLOCK NOINHERIT /) { |
| 203 | my ($bit, $func) = (0, "Fcntl::O_" . $oflag); |
| 204 | no strict 'refs'; |
| 205 | $OPENFLAGS |= $bit if eval { |
| 206 | # Make sure that redefined die handlers do not cause problems |
| 207 | # eg CGI::Carp |
| 208 | local $SIG{__DIE__} = sub {}; |
| 209 | local $SIG{__WARN__} = sub {}; |
| 210 | $bit = &$func(); |
| 211 | 1; |
| 212 | }; |
| 213 | } |
| 214 | } |
| 215 | |
| 216 | # On some systems the O_TEMPORARY flag can be used to tell the OS |
| 217 | # to automatically remove the file when it is closed. This is fine |
| 218 | # in most cases but not if tempfile is called with UNLINK=>0 and |
| 219 | # the filename is requested -- in the case where the filename is to |
| 220 | # be passed to another routine. This happens on windows. We overcome |
| 221 | # this by using a second open flags variable |
| 222 | |
| 223 | my $OPENTEMPFLAGS = $OPENFLAGS; |
| 224 | unless ($^O eq 'MacOS') { |
| 225 | for my $oflag (qw/ TEMPORARY /) { |
| 226 | my ($bit, $func) = (0, "Fcntl::O_" . $oflag); |
| 227 | no strict 'refs'; |
| 228 | $OPENTEMPFLAGS |= $bit if eval { |
| 229 | # Make sure that redefined die handlers do not cause problems |
| 230 | # eg CGI::Carp |
| 231 | local $SIG{__DIE__} = sub {}; |
| 232 | local $SIG{__WARN__} = sub {}; |
| 233 | $bit = &$func(); |
| 234 | 1; |
| 235 | }; |
| 236 | } |
| 237 | } |
| 238 | |
| 239 | # INTERNAL ROUTINES - not to be used outside of package |
| 240 | |
| 241 | # Generic routine for getting a temporary filename |
| 242 | # modelled on OpenBSD _gettemp() in mktemp.c |
| 243 | |
| 244 | # The template must contain X's that are to be replaced |
| 245 | # with the random values |
| 246 | |
| 247 | # Arguments: |
| 248 | |
| 249 | # TEMPLATE - string containing the XXXXX's that is converted |
| 250 | # to a random filename and opened if required |
| 251 | |
| 252 | # Optionally, a hash can also be supplied containing specific options |
| 253 | # "open" => if true open the temp file, else just return the name |
| 254 | # default is 0 |
| 255 | # "mkdir"=> if true, we are creating a temp directory rather than tempfile |
| 256 | # default is 0 |
| 257 | # "suffixlen" => number of characters at end of PATH to be ignored. |
| 258 | # default is 0. |
| 259 | # "unlink_on_close" => indicates that, if possible, the OS should remove |
| 260 | # the file as soon as it is closed. Usually indicates |
| 261 | # use of the O_TEMPORARY flag to sysopen. |
| 262 | # Usually irrelevant on unix |
| 263 | |
| 264 | # Optionally a reference to a scalar can be passed into the function |
| 265 | # On error this will be used to store the reason for the error |
| 266 | # "ErrStr" => \$errstr |
| 267 | |
| 268 | # "open" and "mkdir" can not both be true |
| 269 | # "unlink_on_close" is not used when "mkdir" is true. |
| 270 | |
| 271 | # The default options are equivalent to mktemp(). |
| 272 | |
| 273 | # Returns: |
| 274 | # filehandle - open file handle (if called with doopen=1, else undef) |
| 275 | # temp name - name of the temp file or directory |
| 276 | |
| 277 | # For example: |
| 278 | # ($fh, $name) = _gettemp($template, "open" => 1); |
| 279 | |
| 280 | # for the current version, failures are associated with |
| 281 | # stored in an error string and returned to give the reason whilst debugging |
| 282 | # This routine is not called by any external function |
| 283 | sub _gettemp { |
| 284 | |
| 285 | croak 'Usage: ($fh, $name) = _gettemp($template, OPTIONS);' |
| 286 | unless scalar(@_) >= 1; |
| 287 | |
| 288 | # the internal error string - expect it to be overridden |
| 289 | # Need this in case the caller decides not to supply us a value |
| 290 | # need an anonymous scalar |
| 291 | my $tempErrStr; |
| 292 | |
| 293 | # Default options |
| 294 | my %options = ( |
| 295 | "open" => 0, |
| 296 | "mkdir" => 0, |
| 297 | "suffixlen" => 0, |
| 298 | "unlink_on_close" => 0, |
| 299 | "ErrStr" => \$tempErrStr, |
| 300 | ); |
| 301 | |
| 302 | # Read the template |
| 303 | my $template = shift; |
| 304 | if (ref($template)) { |
| 305 | # Use a warning here since we have not yet merged ErrStr |
| 306 | carp "File::Temp::_gettemp: template must not be a reference"; |
| 307 | return (); |
| 308 | } |
| 309 | |
| 310 | # Check that the number of entries on stack are even |
| 311 | if (scalar(@_) % 2 != 0) { |
| 312 | # Use a warning here since we have not yet merged ErrStr |
| 313 | carp "File::Temp::_gettemp: Must have even number of options"; |
| 314 | return (); |
| 315 | } |
| 316 | |
| 317 | # Read the options and merge with defaults |
| 318 | %options = (%options, @_) if @_; |
| 319 | |
| 320 | # Make sure the error string is set to undef |
| 321 | ${$options{ErrStr}} = undef; |
| 322 | |
| 323 | # Can not open the file and make a directory in a single call |
| 324 | if ($options{"open"} && $options{"mkdir"}) { |
| 325 | ${$options{ErrStr}} = "doopen and domkdir can not both be true\n"; |
| 326 | return (); |
| 327 | } |
| 328 | |
| 329 | # Find the start of the end of the Xs (position of last X) |
| 330 | # Substr starts from 0 |
| 331 | my $start = length($template) - 1 - $options{"suffixlen"}; |
| 332 | |
| 333 | # Check that we have at least MINX x X (eg 'XXXX") at the end of the string |
| 334 | # (taking suffixlen into account). Any fewer is insecure. |
| 335 | |
| 336 | # Do it using substr - no reason to use a pattern match since |
| 337 | # we know where we are looking and what we are looking for |
| 338 | |
| 339 | if (substr($template, $start - MINX + 1, MINX) ne 'X' x MINX) { |
| 340 | ${$options{ErrStr}} = "The template must contain at least ". |
| 341 | MINX . " 'X' characters\n"; |
| 342 | return (); |
| 343 | } |
| 344 | |
| 345 | # Replace all the X at the end of the substring with a |
| 346 | # random character or just all the XX at the end of a full string. |
| 347 | # Do it as an if, since the suffix adjusts which section to replace |
| 348 | # and suffixlen=0 returns nothing if used in the substr directly |
| 349 | # and generate a full path from the template |
| 350 | |
| 351 | my $path = _replace_XX($template, $options{"suffixlen"}); |
| 352 | |
| 353 | |
| 354 | # Split the path into constituent parts - eventually we need to check |
| 355 | # whether the directory exists |
| 356 | # We need to know whether we are making a temp directory |
| 357 | # or a tempfile |
| 358 | |
| 359 | my ($volume, $directories, $file); |
| 360 | my $parent; # parent directory |
| 361 | if ($options{"mkdir"}) { |
| 362 | # There is no filename at the end |
| 363 | ($volume, $directories, $file) = File::Spec->splitpath( $path, 1); |
| 364 | |
| 365 | # The parent is then $directories without the last directory |
| 366 | # Split the directory and put it back together again |
| 367 | my @dirs = File::Spec->splitdir($directories); |
| 368 | |
| 369 | # If @dirs only has one entry (i.e. the directory template) that means |
| 370 | # we are in the current directory |
| 371 | if ($#dirs == 0) { |
| 372 | $parent = File::Spec->curdir; |
| 373 | } else { |
| 374 | |
| 375 | if ($^O eq 'VMS') { # need volume to avoid relative dir spec |
| 376 | $parent = File::Spec->catdir($volume, @dirs[0..$#dirs-1]); |
| 377 | $parent = 'sys$disk:[]' if $parent eq ''; |
| 378 | } else { |
| 379 | |
| 380 | # Put it back together without the last one |
| 381 | $parent = File::Spec->catdir(@dirs[0..$#dirs-1]); |
| 382 | |
| 383 | # ...and attach the volume (no filename) |
| 384 | $parent = File::Spec->catpath($volume, $parent, ''); |
| 385 | } |
| 386 | |
| 387 | } |
| 388 | |
| 389 | } else { |
| 390 | |
| 391 | # Get rid of the last filename (use File::Basename for this?) |
| 392 | ($volume, $directories, $file) = File::Spec->splitpath( $path ); |
| 393 | |
| 394 | # Join up without the file part |
| 395 | $parent = File::Spec->catpath($volume,$directories,''); |
| 396 | |
| 397 | # If $parent is empty replace with curdir |
| 398 | $parent = File::Spec->curdir |
| 399 | unless $directories ne ''; |
| 400 | |
| 401 | } |
| 402 | |
| 403 | # Check that the parent directories exist |
| 404 | # Do this even for the case where we are simply returning a name |
| 405 | # not a file -- no point returning a name that includes a directory |
| 406 | # that does not exist or is not writable |
| 407 | |
| 408 | unless (-d $parent) { |
| 409 | ${$options{ErrStr}} = "Parent directory ($parent) is not a directory"; |
| 410 | return (); |
| 411 | } |
| 412 | unless (-w _) { |
| 413 | ${$options{ErrStr}} = "Parent directory ($parent) is not writable\n"; |
| 414 | return (); |
| 415 | } |
| 416 | |
| 417 | |
| 418 | # Check the stickiness of the directory and chown giveaway if required |
| 419 | # If the directory is world writable the sticky bit |
| 420 | # must be set |
| 421 | |
| 422 | if (File::Temp->safe_level == MEDIUM) { |
| 423 | my $safeerr; |
| 424 | unless (_is_safe($parent,\$safeerr)) { |
| 425 | ${$options{ErrStr}} = "Parent directory ($parent) is not safe ($safeerr)"; |
| 426 | return (); |
| 427 | } |
| 428 | } elsif (File::Temp->safe_level == HIGH) { |
| 429 | my $safeerr; |
| 430 | unless (_is_verysafe($parent, \$safeerr)) { |
| 431 | ${$options{ErrStr}} = "Parent directory ($parent) is not safe ($safeerr)"; |
| 432 | return (); |
| 433 | } |
| 434 | } |
| 435 | |
| 436 | |
| 437 | # Now try MAX_TRIES time to open the file |
| 438 | for (my $i = 0; $i < MAX_TRIES; $i++) { |
| 439 | |
| 440 | # Try to open the file if requested |
| 441 | if ($options{"open"}) { |
| 442 | my $fh; |
| 443 | |
| 444 | # If we are running before perl5.6.0 we can not auto-vivify |
| 445 | if ($] < 5.006) { |
| 446 | $fh = &Symbol::gensym; |
| 447 | } |
| 448 | |
| 449 | # Try to make sure this will be marked close-on-exec |
| 450 | # XXX: Win32 doesn't respect this, nor the proper fcntl, |
| 451 | # but may have O_NOINHERIT. This may or may not be in Fcntl. |
| 452 | local $^F = 2; |
| 453 | |
| 454 | # Store callers umask |
| 455 | my $umask = umask(); |
| 456 | |
| 457 | # Set a known umask |
| 458 | umask(066); |
| 459 | |
| 460 | # Attempt to open the file |
| 461 | my $open_success = undef; |
| 462 | if ( $^O eq 'VMS' and $options{"unlink_on_close"} ) { |
| 463 | # make it auto delete on close by setting FAB$V_DLT bit |
| 464 | $fh = VMS::Stdio::vmssysopen($path, $OPENFLAGS, 0600, 'fop=dlt'); |
| 465 | $open_success = $fh; |
| 466 | } else { |
| 467 | my $flags = ( $options{"unlink_on_close"} ? |
| 468 | $OPENTEMPFLAGS : |
| 469 | $OPENFLAGS ); |
| 470 | $open_success = sysopen($fh, $path, $flags, 0600); |
| 471 | } |
| 472 | if ( $open_success ) { |
| 473 | |
| 474 | # Reset umask |
| 475 | umask($umask) if defined $umask; |
| 476 | |
| 477 | # Opened successfully - return file handle and name |
| 478 | return ($fh, $path); |
| 479 | |
| 480 | } else { |
| 481 | # Reset umask |
| 482 | umask($umask) if defined $umask; |
| 483 | |
| 484 | # Error opening file - abort with error |
| 485 | # if the reason was anything but EEXIST |
| 486 | unless ($!{EEXIST}) { |
| 487 | ${$options{ErrStr}} = "Could not create temp file $path: $!"; |
| 488 | return (); |
| 489 | } |
| 490 | |
| 491 | # Loop round for another try |
| 492 | |
| 493 | } |
| 494 | } elsif ($options{"mkdir"}) { |
| 495 | |
| 496 | # Store callers umask |
| 497 | my $umask = umask(); |
| 498 | |
| 499 | # Set a known umask |
| 500 | umask(066); |
| 501 | |
| 502 | # Open the temp directory |
| 503 | if (mkdir( $path, 0700)) { |
| 504 | # created okay |
| 505 | # Reset umask |
| 506 | umask($umask) if defined $umask; |
| 507 | |
| 508 | return undef, $path; |
| 509 | } else { |
| 510 | |
| 511 | # Reset umask |
| 512 | umask($umask) if defined $umask; |
| 513 | |
| 514 | # Abort with error if the reason for failure was anything |
| 515 | # except EEXIST |
| 516 | unless ($!{EEXIST}) { |
| 517 | ${$options{ErrStr}} = "Could not create directory $path: $!"; |
| 518 | return (); |
| 519 | } |
| 520 | |
| 521 | # Loop round for another try |
| 522 | |
| 523 | } |
| 524 | |
| 525 | } else { |
| 526 | |
| 527 | # Return true if the file can not be found |
| 528 | # Directory has been checked previously |
| 529 | |
| 530 | return (undef, $path) unless -e $path; |
| 531 | |
| 532 | # Try again until MAX_TRIES |
| 533 | |
| 534 | } |
| 535 | |
| 536 | # Did not successfully open the tempfile/dir |
| 537 | # so try again with a different set of random letters |
| 538 | # No point in trying to increment unless we have only |
| 539 | # 1 X say and the randomness could come up with the same |
| 540 | # file MAX_TRIES in a row. |
| 541 | |
| 542 | # Store current attempt - in principal this implies that the |
| 543 | # 3rd time around the open attempt that the first temp file |
| 544 | # name could be generated again. Probably should store each |
| 545 | # attempt and make sure that none are repeated |
| 546 | |
| 547 | my $original = $path; |
| 548 | my $counter = 0; # Stop infinite loop |
| 549 | my $MAX_GUESS = 50; |
| 550 | |
| 551 | do { |
| 552 | |
| 553 | # Generate new name from original template |
| 554 | $path = _replace_XX($template, $options{"suffixlen"}); |
| 555 | |
| 556 | $counter++; |
| 557 | |
| 558 | } until ($path ne $original || $counter > $MAX_GUESS); |
| 559 | |
| 560 | # Check for out of control looping |
| 561 | if ($counter > $MAX_GUESS) { |
| 562 | ${$options{ErrStr}} = "Tried to get a new temp name different to the previous value $MAX_GUESS times.\nSomething wrong with template?? ($template)"; |
| 563 | return (); |
| 564 | } |
| 565 | |
| 566 | } |
| 567 | |
| 568 | # If we get here, we have run out of tries |
| 569 | ${ $options{ErrStr} } = "Have exceeded the maximum number of attempts (" |
| 570 | . MAX_TRIES . ") to open temp file/dir"; |
| 571 | |
| 572 | return (); |
| 573 | |
| 574 | } |
| 575 | |
| 576 | # Internal routine to return a random character from the |
| 577 | # character list. Does not do an srand() since rand() |
| 578 | # will do one automatically |
| 579 | |
| 580 | # No arguments. Return value is the random character |
| 581 | |
| 582 | # No longer called since _replace_XX runs a few percent faster if |
| 583 | # I inline the code. This is important if we are creating thousands of |
| 584 | # temporary files. |
| 585 | |
| 586 | sub _randchar { |
| 587 | |
| 588 | $CHARS[ int( rand( $#CHARS ) ) ]; |
| 589 | |
| 590 | } |
| 591 | |
| 592 | # Internal routine to replace the XXXX... with random characters |
| 593 | # This has to be done by _gettemp() every time it fails to |
| 594 | # open a temp file/dir |
| 595 | |
| 596 | # Arguments: $template (the template with XXX), |
| 597 | # $ignore (number of characters at end to ignore) |
| 598 | |
| 599 | # Returns: modified template |
| 600 | |
| 601 | sub _replace_XX { |
| 602 | |
| 603 | croak 'Usage: _replace_XX($template, $ignore)' |
| 604 | unless scalar(@_) == 2; |
| 605 | |
| 606 | my ($path, $ignore) = @_; |
| 607 | |
| 608 | # Do it as an if, since the suffix adjusts which section to replace |
| 609 | # and suffixlen=0 returns nothing if used in the substr directly |
| 610 | # Alternatively, could simply set $ignore to length($path)-1 |
| 611 | # Don't want to always use substr when not required though. |
| 612 | |
| 613 | if ($ignore) { |
| 614 | substr($path, 0, - $ignore) =~ s/X(?=X*\z)/$CHARS[ int( rand( $#CHARS ) ) ]/ge; |
| 615 | } else { |
| 616 | $path =~ s/X(?=X*\z)/$CHARS[ int( rand( $#CHARS ) ) ]/ge; |
| 617 | } |
| 618 | |
| 619 | return $path; |
| 620 | } |
| 621 | |
| 622 | # internal routine to check to see if the directory is safe |
| 623 | # First checks to see if the directory is not owned by the |
| 624 | # current user or root. Then checks to see if anyone else |
| 625 | # can write to the directory and if so, checks to see if |
| 626 | # it has the sticky bit set |
| 627 | |
| 628 | # Will not work on systems that do not support sticky bit |
| 629 | |
| 630 | #Args: directory path to check |
| 631 | # Optionally: reference to scalar to contain error message |
| 632 | # Returns true if the path is safe and false otherwise. |
| 633 | # Returns undef if can not even run stat() on the path |
| 634 | |
| 635 | # This routine based on version written by Tom Christiansen |
| 636 | |
| 637 | # Presumably, by the time we actually attempt to create the |
| 638 | # file or directory in this directory, it may not be safe |
| 639 | # anymore... Have to run _is_safe directly after the open. |
| 640 | |
| 641 | sub _is_safe { |
| 642 | |
| 643 | my $path = shift; |
| 644 | my $err_ref = shift; |
| 645 | |
| 646 | # Stat path |
| 647 | my @info = stat($path); |
| 648 | unless (scalar(@info)) { |
| 649 | $$err_ref = "stat(path) returned no values"; |
| 650 | return 0; |
| 651 | }; |
| 652 | return 1 if $^O eq 'VMS'; # owner delete control at file level |
| 653 | |
| 654 | # Check to see whether owner is neither superuser (or a system uid) nor me |
| 655 | # Use the real uid from the $< variable |
| 656 | # UID is in [4] |
| 657 | if ($info[4] > File::Temp->top_system_uid() && $info[4] != $<) { |
| 658 | |
| 659 | Carp::cluck(sprintf "uid=$info[4] topuid=%s \$<=$< path='$path'", |
| 660 | File::Temp->top_system_uid()); |
| 661 | |
| 662 | $$err_ref = "Directory owned neither by root nor the current user" |
| 663 | if ref($err_ref); |
| 664 | return 0; |
| 665 | } |
| 666 | |
| 667 | # check whether group or other can write file |
| 668 | # use 066 to detect either reading or writing |
| 669 | # use 022 to check writability |
| 670 | # Do it with S_IWOTH and S_IWGRP for portability (maybe) |
| 671 | # mode is in info[2] |
| 672 | if (($info[2] & &Fcntl::S_IWGRP) || # Is group writable? |
| 673 | ($info[2] & &Fcntl::S_IWOTH) ) { # Is world writable? |
| 674 | # Must be a directory |
| 675 | unless (-d _) { |
| 676 | $$err_ref = "Path ($path) is not a directory" |
| 677 | if ref($err_ref); |
| 678 | return 0; |
| 679 | } |
| 680 | # Must have sticky bit set |
| 681 | unless (-k _) { |
| 682 | $$err_ref = "Sticky bit not set on $path when dir is group|world writable" |
| 683 | if ref($err_ref); |
| 684 | return 0; |
| 685 | } |
| 686 | } |
| 687 | |
| 688 | return 1; |
| 689 | } |
| 690 | |
| 691 | # Internal routine to check whether a directory is safe |
| 692 | # for temp files. Safer than _is_safe since it checks for |
| 693 | # the possibility of chown giveaway and if that is a possibility |
| 694 | # checks each directory in the path to see if it is safe (with _is_safe) |
| 695 | |
| 696 | # If _PC_CHOWN_RESTRICTED is not set, does the full test of each |
| 697 | # directory anyway. |
| 698 | |
| 699 | # Takes optional second arg as scalar ref to error reason |
| 700 | |
| 701 | sub _is_verysafe { |
| 702 | |
| 703 | # Need POSIX - but only want to bother if really necessary due to overhead |
| 704 | require POSIX; |
| 705 | |
| 706 | my $path = shift; |
| 707 | print "_is_verysafe testing $path\n" if $DEBUG; |
| 708 | return 1 if $^O eq 'VMS'; # owner delete control at file level |
| 709 | |
| 710 | my $err_ref = shift; |
| 711 | |
| 712 | # Should Get the value of _PC_CHOWN_RESTRICTED if it is defined |
| 713 | # and If it is not there do the extensive test |
| 714 | my $chown_restricted; |
| 715 | $chown_restricted = &POSIX::_PC_CHOWN_RESTRICTED() |
| 716 | if eval { &POSIX::_PC_CHOWN_RESTRICTED(); 1}; |
| 717 | |
| 718 | # If chown_resticted is set to some value we should test it |
| 719 | if (defined $chown_restricted) { |
| 720 | |
| 721 | # Return if the current directory is safe |
| 722 | return _is_safe($path,$err_ref) if POSIX::sysconf( $chown_restricted ); |
| 723 | |
| 724 | } |
| 725 | |
| 726 | # To reach this point either, the _PC_CHOWN_RESTRICTED symbol |
| 727 | # was not avialable or the symbol was there but chown giveaway |
| 728 | # is allowed. Either way, we now have to test the entire tree for |
| 729 | # safety. |
| 730 | |
| 731 | # Convert path to an absolute directory if required |
| 732 | unless (File::Spec->file_name_is_absolute($path)) { |
| 733 | $path = File::Spec->rel2abs($path); |
| 734 | } |
| 735 | |
| 736 | # Split directory into components - assume no file |
| 737 | my ($volume, $directories, undef) = File::Spec->splitpath( $path, 1); |
| 738 | |
| 739 | # Slightly less efficient than having a function in File::Spec |
| 740 | # to chop off the end of a directory or even a function that |
| 741 | # can handle ../ in a directory tree |
| 742 | # Sometimes splitdir() returns a blank at the end |
| 743 | # so we will probably check the bottom directory twice in some cases |
| 744 | my @dirs = File::Spec->splitdir($directories); |
| 745 | |
| 746 | # Concatenate one less directory each time around |
| 747 | foreach my $pos (0.. $#dirs) { |
| 748 | # Get a directory name |
| 749 | my $dir = File::Spec->catpath($volume, |
| 750 | File::Spec->catdir(@dirs[0.. $#dirs - $pos]), |
| 751 | '' |
| 752 | ); |
| 753 | |
| 754 | print "TESTING DIR $dir\n" if $DEBUG; |
| 755 | |
| 756 | # Check the directory |
| 757 | return 0 unless _is_safe($dir,$err_ref); |
| 758 | |
| 759 | } |
| 760 | |
| 761 | return 1; |
| 762 | } |
| 763 | |
| 764 | |
| 765 | |
| 766 | # internal routine to determine whether unlink works on this |
| 767 | # platform for files that are currently open. |
| 768 | # Returns true if we can, false otherwise. |
| 769 | |
| 770 | # Currently WinNT, OS/2 and VMS can not unlink an opened file |
| 771 | # On VMS this is because the O_EXCL flag is used to open the |
| 772 | # temporary file. Currently I do not know enough about the issues |
| 773 | # on VMS to decide whether O_EXCL is a requirement. |
| 774 | |
| 775 | sub _can_unlink_opened_file { |
| 776 | |
| 777 | if ($^O eq 'MSWin32' || $^O eq 'os2' || $^O eq 'VMS' || $^O eq 'dos' || $^O eq 'MacOS') { |
| 778 | return 0; |
| 779 | } else { |
| 780 | return 1; |
| 781 | } |
| 782 | |
| 783 | } |
| 784 | |
| 785 | # internal routine to decide which security levels are allowed |
| 786 | # see safe_level() for more information on this |
| 787 | |
| 788 | # Controls whether the supplied security level is allowed |
| 789 | |
| 790 | # $cando = _can_do_level( $level ) |
| 791 | |
| 792 | sub _can_do_level { |
| 793 | |
| 794 | # Get security level |
| 795 | my $level = shift; |
| 796 | |
| 797 | # Always have to be able to do STANDARD |
| 798 | return 1 if $level == STANDARD; |
| 799 | |
| 800 | # Currently, the systems that can do HIGH or MEDIUM are identical |
| 801 | if ( $^O eq 'MSWin32' || $^O eq 'os2' || $^O eq 'cygwin' || $^O eq 'dos' || $^O eq 'MacOS') { |
| 802 | return 0; |
| 803 | } else { |
| 804 | return 1; |
| 805 | } |
| 806 | |
| 807 | } |
| 808 | |
| 809 | # This routine sets up a deferred unlinking of a specified |
| 810 | # filename and filehandle. It is used in the following cases: |
| 811 | # - Called by unlink0 if an opened file can not be unlinked |
| 812 | # - Called by tempfile() if files are to be removed on shutdown |
| 813 | # - Called by tempdir() if directories are to be removed on shutdown |
| 814 | |
| 815 | # Arguments: |
| 816 | # _deferred_unlink( $fh, $fname, $isdir ); |
| 817 | # |
| 818 | # - filehandle (so that it can be expclicitly closed if open |
| 819 | # - filename (the thing we want to remove) |
| 820 | # - isdir (flag to indicate that we are being given a directory) |
| 821 | # [and hence no filehandle] |
| 822 | |
| 823 | # Status is not referred to since all the magic is done with an END block |
| 824 | |
| 825 | { |
| 826 | # Will set up two lexical variables to contain all the files to be |
| 827 | # removed. One array for files, another for directories |
| 828 | # They will only exist in this block |
| 829 | # This means we only have to set up a single END block to remove all files |
| 830 | # @files_to_unlink contains an array ref with the filehandle and filename |
| 831 | my (@files_to_unlink, @dirs_to_unlink); |
| 832 | |
| 833 | # Set up an end block to use these arrays |
| 834 | END { |
| 835 | # Files |
| 836 | foreach my $file (@files_to_unlink) { |
| 837 | # close the filehandle without checking its state |
| 838 | # in order to make real sure that this is closed |
| 839 | # if its already closed then I dont care about the answer |
| 840 | # probably a better way to do this |
| 841 | close($file->[0]); # file handle is [0] |
| 842 | |
| 843 | if (-f $file->[1]) { # file name is [1] |
| 844 | unlink $file->[1] or warn "Error removing ".$file->[1]; |
| 845 | } |
| 846 | } |
| 847 | # Dirs |
| 848 | foreach my $dir (@dirs_to_unlink) { |
| 849 | if (-d $dir) { |
| 850 | rmtree($dir, $DEBUG, 1); |
| 851 | } |
| 852 | } |
| 853 | |
| 854 | } |
| 855 | |
| 856 | # This is the sub called to register a file for deferred unlinking |
| 857 | # This could simply store the input parameters and defer everything |
| 858 | # until the END block. For now we do a bit of checking at this |
| 859 | # point in order to make sure that (1) we have a file/dir to delete |
| 860 | # and (2) we have been called with the correct arguments. |
| 861 | sub _deferred_unlink { |
| 862 | |
| 863 | croak 'Usage: _deferred_unlink($fh, $fname, $isdir)' |
| 864 | unless scalar(@_) == 3; |
| 865 | |
| 866 | my ($fh, $fname, $isdir) = @_; |
| 867 | |
| 868 | warn "Setting up deferred removal of $fname\n" |
| 869 | if $DEBUG; |
| 870 | |
| 871 | # If we have a directory, check that it is a directory |
| 872 | if ($isdir) { |
| 873 | |
| 874 | if (-d $fname) { |
| 875 | |
| 876 | # Directory exists so store it |
| 877 | # first on VMS turn []foo into [.foo] for rmtree |
| 878 | $fname = VMS::Filespec::vmspath($fname) if $^O eq 'VMS'; |
| 879 | push (@dirs_to_unlink, $fname); |
| 880 | |
| 881 | } else { |
| 882 | carp "Request to remove directory $fname could not be completed since it does not exist!\n" if $^W; |
| 883 | } |
| 884 | |
| 885 | } else { |
| 886 | |
| 887 | if (-f $fname) { |
| 888 | |
| 889 | # file exists so store handle and name for later removal |
| 890 | push(@files_to_unlink, [$fh, $fname]); |
| 891 | |
| 892 | } else { |
| 893 | carp "Request to remove file $fname could not be completed since it is not there!\n" if $^W; |
| 894 | } |
| 895 | |
| 896 | } |
| 897 | |
| 898 | } |
| 899 | |
| 900 | |
| 901 | } |
| 902 | |
| 903 | =head1 FUNCTIONS |
| 904 | |
| 905 | This section describes the recommended interface for generating |
| 906 | temporary files and directories. |
| 907 | |
| 908 | =over 4 |
| 909 | |
| 910 | =item B<tempfile> |
| 911 | |
| 912 | This is the basic function to generate temporary files. |
| 913 | The behaviour of the file can be changed using various options: |
| 914 | |
| 915 | ($fh, $filename) = tempfile(); |
| 916 | |
| 917 | Create a temporary file in the directory specified for temporary |
| 918 | files, as specified by the tmpdir() function in L<File::Spec>. |
| 919 | |
| 920 | ($fh, $filename) = tempfile($template); |
| 921 | |
| 922 | Create a temporary file in the current directory using the supplied |
| 923 | template. Trailing `X' characters are replaced with random letters to |
| 924 | generate the filename. At least four `X' characters must be present |
| 925 | in the template. |
| 926 | |
| 927 | ($fh, $filename) = tempfile($template, SUFFIX => $suffix) |
| 928 | |
| 929 | Same as previously, except that a suffix is added to the template |
| 930 | after the `X' translation. Useful for ensuring that a temporary |
| 931 | filename has a particular extension when needed by other applications. |
| 932 | But see the WARNING at the end. |
| 933 | |
| 934 | ($fh, $filename) = tempfile($template, DIR => $dir); |
| 935 | |
| 936 | Translates the template as before except that a directory name |
| 937 | is specified. |
| 938 | |
| 939 | ($fh, $filename) = tempfile($template, UNLINK => 1); |
| 940 | |
| 941 | Return the filename and filehandle as before except that the file is |
| 942 | automatically removed when the program exits. Default is for the file |
| 943 | to be removed if a file handle is requested and to be kept if the |
| 944 | filename is requested. In a scalar context (where no filename is |
| 945 | returned) the file is always deleted either on exit or when it is closed. |
| 946 | |
| 947 | If the template is not specified, a template is always |
| 948 | automatically generated. This temporary file is placed in tmpdir() |
| 949 | (L<File::Spec>) unless a directory is specified explicitly with the |
| 950 | DIR option. |
| 951 | |
| 952 | $fh = tempfile( $template, DIR => $dir ); |
| 953 | |
| 954 | If called in scalar context, only the filehandle is returned |
| 955 | and the file will automatically be deleted when closed (see |
| 956 | the description of tmpfile() elsewhere in this document). |
| 957 | This is the preferred mode of operation, as if you only |
| 958 | have a filehandle, you can never create a race condition |
| 959 | by fumbling with the filename. On systems that can not unlink |
| 960 | an open file or can not mark a file as temporary when it is opened |
| 961 | (for example, Windows NT uses the C<O_TEMPORARY> flag)) |
| 962 | the file is marked for deletion when the program ends (equivalent |
| 963 | to setting UNLINK to 1). The C<UNLINK> flag is ignored if present. |
| 964 | |
| 965 | (undef, $filename) = tempfile($template, OPEN => 0); |
| 966 | |
| 967 | This will return the filename based on the template but |
| 968 | will not open this file. Cannot be used in conjunction with |
| 969 | UNLINK set to true. Default is to always open the file |
| 970 | to protect from possible race conditions. A warning is issued |
| 971 | if warnings are turned on. Consider using the tmpnam() |
| 972 | and mktemp() functions described elsewhere in this document |
| 973 | if opening the file is not required. |
| 974 | |
| 975 | Options can be combined as required. |
| 976 | |
| 977 | =cut |
| 978 | |
| 979 | sub tempfile { |
| 980 | |
| 981 | # Can not check for argument count since we can have any |
| 982 | # number of args |
| 983 | |
| 984 | # Default options |
| 985 | my %options = ( |
| 986 | "DIR" => undef, # Directory prefix |
| 987 | "SUFFIX" => '', # Template suffix |
| 988 | "UNLINK" => 0, # Do not unlink file on exit |
| 989 | "OPEN" => 1, # Open file |
| 990 | ); |
| 991 | |
| 992 | # Check to see whether we have an odd or even number of arguments |
| 993 | my $template = (scalar(@_) % 2 == 1 ? shift(@_) : undef); |
| 994 | |
| 995 | # Read the options and merge with defaults |
| 996 | %options = (%options, @_) if @_; |
| 997 | |
| 998 | # First decision is whether or not to open the file |
| 999 | if (! $options{"OPEN"}) { |
| 1000 | |
| 1001 | warn "tempfile(): temporary filename requested but not opened.\nPossibly unsafe, consider using tempfile() with OPEN set to true\n" |
| 1002 | if $^W; |
| 1003 | |
| 1004 | } |
| 1005 | |
| 1006 | if ($options{"DIR"} and $^O eq 'VMS') { |
| 1007 | |
| 1008 | # on VMS turn []foo into [.foo] for concatenation |
| 1009 | $options{"DIR"} = VMS::Filespec::vmspath($options{"DIR"}); |
| 1010 | } |
| 1011 | |
| 1012 | # Construct the template |
| 1013 | |
| 1014 | # Have a choice of trying to work around the mkstemp/mktemp/tmpnam etc |
| 1015 | # functions or simply constructing a template and using _gettemp() |
| 1016 | # explicitly. Go for the latter |
| 1017 | |
| 1018 | # First generate a template if not defined and prefix the directory |
| 1019 | # If no template must prefix the temp directory |
| 1020 | if (defined $template) { |
| 1021 | if ($options{"DIR"}) { |
| 1022 | |
| 1023 | $template = File::Spec->catfile($options{"DIR"}, $template); |
| 1024 | |
| 1025 | } |
| 1026 | |
| 1027 | } else { |
| 1028 | |
| 1029 | if ($options{"DIR"}) { |
| 1030 | |
| 1031 | $template = File::Spec->catfile($options{"DIR"}, TEMPXXX); |
| 1032 | |
| 1033 | } else { |
| 1034 | |
| 1035 | $template = File::Spec->catfile(File::Spec->tmpdir, TEMPXXX); |
| 1036 | |
| 1037 | } |
| 1038 | |
| 1039 | } |
| 1040 | |
| 1041 | # Now add a suffix |
| 1042 | $template .= $options{"SUFFIX"}; |
| 1043 | |
| 1044 | # Determine whether we should tell _gettemp to unlink the file |
| 1045 | # On unix this is irrelevant and can be worked out after the file is |
| 1046 | # opened (simply by unlinking the open filehandle). On Windows or VMS |
| 1047 | # we have to indicate temporary-ness when we open the file. In general |
| 1048 | # we only want a true temporary file if we are returning just the |
| 1049 | # filehandle - if the user wants the filename they probably do not |
| 1050 | # want the file to disappear as soon as they close it. |
| 1051 | # For this reason, tie unlink_on_close to the return context regardless |
| 1052 | # of OS. |
| 1053 | my $unlink_on_close = ( wantarray ? 0 : 1); |
| 1054 | |
| 1055 | # Create the file |
| 1056 | my ($fh, $path, $errstr); |
| 1057 | croak "Error in tempfile() using $template: $errstr" |
| 1058 | unless (($fh, $path) = _gettemp($template, |
| 1059 | "open" => $options{'OPEN'}, |
| 1060 | "mkdir"=> 0 , |
| 1061 | "unlink_on_close" => $unlink_on_close, |
| 1062 | "suffixlen" => length($options{'SUFFIX'}), |
| 1063 | "ErrStr" => \$errstr, |
| 1064 | ) ); |
| 1065 | |
| 1066 | # Set up an exit handler that can do whatever is right for the |
| 1067 | # system. This removes files at exit when requested explicitly or when |
| 1068 | # system is asked to unlink_on_close but is unable to do so because |
| 1069 | # of OS limitations. |
| 1070 | # The latter should be achieved by using a tied filehandle. |
| 1071 | # Do not check return status since this is all done with END blocks. |
| 1072 | _deferred_unlink($fh, $path, 0) if $options{"UNLINK"}; |
| 1073 | |
| 1074 | # Return |
| 1075 | if (wantarray()) { |
| 1076 | |
| 1077 | if ($options{'OPEN'}) { |
| 1078 | return ($fh, $path); |
| 1079 | } else { |
| 1080 | return (undef, $path); |
| 1081 | } |
| 1082 | |
| 1083 | } else { |
| 1084 | |
| 1085 | # Unlink the file. It is up to unlink0 to decide what to do with |
| 1086 | # this (whether to unlink now or to defer until later) |
| 1087 | unlink0($fh, $path) or croak "Error unlinking file $path using unlink0"; |
| 1088 | |
| 1089 | # Return just the filehandle. |
| 1090 | return $fh; |
| 1091 | } |
| 1092 | |
| 1093 | |
| 1094 | } |
| 1095 | |
| 1096 | =item B<tempdir> |
| 1097 | |
| 1098 | This is the recommended interface for creation of temporary directories. |
| 1099 | The behaviour of the function depends on the arguments: |
| 1100 | |
| 1101 | $tempdir = tempdir(); |
| 1102 | |
| 1103 | Create a directory in tmpdir() (see L<File::Spec|File::Spec>). |
| 1104 | |
| 1105 | $tempdir = tempdir( $template ); |
| 1106 | |
| 1107 | Create a directory from the supplied template. This template is |
| 1108 | similar to that described for tempfile(). `X' characters at the end |
| 1109 | of the template are replaced with random letters to construct the |
| 1110 | directory name. At least four `X' characters must be in the template. |
| 1111 | |
| 1112 | $tempdir = tempdir ( DIR => $dir ); |
| 1113 | |
| 1114 | Specifies the directory to use for the temporary directory. |
| 1115 | The temporary directory name is derived from an internal template. |
| 1116 | |
| 1117 | $tempdir = tempdir ( $template, DIR => $dir ); |
| 1118 | |
| 1119 | Prepend the supplied directory name to the template. The template |
| 1120 | should not include parent directory specifications itself. Any parent |
| 1121 | directory specifications are removed from the template before |
| 1122 | prepending the supplied directory. |
| 1123 | |
| 1124 | $tempdir = tempdir ( $template, TMPDIR => 1 ); |
| 1125 | |
| 1126 | Using the supplied template, create the temporary directory in |
| 1127 | a standard location for temporary files. Equivalent to doing |
| 1128 | |
| 1129 | $tempdir = tempdir ( $template, DIR => File::Spec->tmpdir); |
| 1130 | |
| 1131 | but shorter. Parent directory specifications are stripped from the |
| 1132 | template itself. The C<TMPDIR> option is ignored if C<DIR> is set |
| 1133 | explicitly. Additionally, C<TMPDIR> is implied if neither a template |
| 1134 | nor a directory are supplied. |
| 1135 | |
| 1136 | $tempdir = tempdir( $template, CLEANUP => 1); |
| 1137 | |
| 1138 | Create a temporary directory using the supplied template, but |
| 1139 | attempt to remove it (and all files inside it) when the program |
| 1140 | exits. Note that an attempt will be made to remove all files from |
| 1141 | the directory even if they were not created by this module (otherwise |
| 1142 | why ask to clean it up?). The directory removal is made with |
| 1143 | the rmtree() function from the L<File::Path|File::Path> module. |
| 1144 | Of course, if the template is not specified, the temporary directory |
| 1145 | will be created in tmpdir() and will also be removed at program exit. |
| 1146 | |
| 1147 | =cut |
| 1148 | |
| 1149 | # ' |
| 1150 | |
| 1151 | sub tempdir { |
| 1152 | |
| 1153 | # Can not check for argument count since we can have any |
| 1154 | # number of args |
| 1155 | |
| 1156 | # Default options |
| 1157 | my %options = ( |
| 1158 | "CLEANUP" => 0, # Remove directory on exit |
| 1159 | "DIR" => '', # Root directory |
| 1160 | "TMPDIR" => 0, # Use tempdir with template |
| 1161 | ); |
| 1162 | |
| 1163 | # Check to see whether we have an odd or even number of arguments |
| 1164 | my $template = (scalar(@_) % 2 == 1 ? shift(@_) : undef ); |
| 1165 | |
| 1166 | # Read the options and merge with defaults |
| 1167 | %options = (%options, @_) if @_; |
| 1168 | |
| 1169 | # Modify or generate the template |
| 1170 | |
| 1171 | # Deal with the DIR and TMPDIR options |
| 1172 | if (defined $template) { |
| 1173 | |
| 1174 | # Need to strip directory path if using DIR or TMPDIR |
| 1175 | if ($options{'TMPDIR'} || $options{'DIR'}) { |
| 1176 | |
| 1177 | # Strip parent directory from the filename |
| 1178 | # |
| 1179 | # There is no filename at the end |
| 1180 | $template = VMS::Filespec::vmspath($template) if $^O eq 'VMS'; |
| 1181 | my ($volume, $directories, undef) = File::Spec->splitpath( $template, 1); |
| 1182 | |
| 1183 | # Last directory is then our template |
| 1184 | $template = (File::Spec->splitdir($directories))[-1]; |
| 1185 | |
| 1186 | # Prepend the supplied directory or temp dir |
| 1187 | if ($options{"DIR"}) { |
| 1188 | |
| 1189 | $template = File::Spec->catdir($options{"DIR"}, $template); |
| 1190 | |
| 1191 | } elsif ($options{TMPDIR}) { |
| 1192 | |
| 1193 | # Prepend tmpdir |
| 1194 | $template = File::Spec->catdir(File::Spec->tmpdir, $template); |
| 1195 | |
| 1196 | } |
| 1197 | |
| 1198 | } |
| 1199 | |
| 1200 | } else { |
| 1201 | |
| 1202 | if ($options{"DIR"}) { |
| 1203 | |
| 1204 | $template = File::Spec->catdir($options{"DIR"}, TEMPXXX); |
| 1205 | |
| 1206 | } else { |
| 1207 | |
| 1208 | $template = File::Spec->catdir(File::Spec->tmpdir, TEMPXXX); |
| 1209 | |
| 1210 | } |
| 1211 | |
| 1212 | } |
| 1213 | |
| 1214 | # Create the directory |
| 1215 | my $tempdir; |
| 1216 | my $suffixlen = 0; |
| 1217 | if ($^O eq 'VMS') { # dir names can end in delimiters |
| 1218 | $template =~ m/([\.\]:>]+)$/; |
| 1219 | $suffixlen = length($1); |
| 1220 | } |
| 1221 | if ( ($^O eq 'MacOS') && (substr($template, -1) eq ':') ) { |
| 1222 | # dir name has a trailing ':' |
| 1223 | ++$suffixlen; |
| 1224 | } |
| 1225 | |
| 1226 | my $errstr; |
| 1227 | croak "Error in tempdir() using $template: $errstr" |
| 1228 | unless ((undef, $tempdir) = _gettemp($template, |
| 1229 | "open" => 0, |
| 1230 | "mkdir"=> 1 , |
| 1231 | "suffixlen" => $suffixlen, |
| 1232 | "ErrStr" => \$errstr, |
| 1233 | ) ); |
| 1234 | |
| 1235 | # Install exit handler; must be dynamic to get lexical |
| 1236 | if ( $options{'CLEANUP'} && -d $tempdir) { |
| 1237 | _deferred_unlink(undef, $tempdir, 1); |
| 1238 | } |
| 1239 | |
| 1240 | # Return the dir name |
| 1241 | return $tempdir; |
| 1242 | |
| 1243 | } |
| 1244 | |
| 1245 | =back |
| 1246 | |
| 1247 | =head1 MKTEMP FUNCTIONS |
| 1248 | |
| 1249 | The following functions are Perl implementations of the |
| 1250 | mktemp() family of temp file generation system calls. |
| 1251 | |
| 1252 | =over 4 |
| 1253 | |
| 1254 | =item B<mkstemp> |
| 1255 | |
| 1256 | Given a template, returns a filehandle to the temporary file and the name |
| 1257 | of the file. |
| 1258 | |
| 1259 | ($fh, $name) = mkstemp( $template ); |
| 1260 | |
| 1261 | In scalar context, just the filehandle is returned. |
| 1262 | |
| 1263 | The template may be any filename with some number of X's appended |
| 1264 | to it, for example F</tmp/temp.XXXX>. The trailing X's are replaced |
| 1265 | with unique alphanumeric combinations. |
| 1266 | |
| 1267 | =cut |
| 1268 | |
| 1269 | |
| 1270 | |
| 1271 | sub mkstemp { |
| 1272 | |
| 1273 | croak "Usage: mkstemp(template)" |
| 1274 | if scalar(@_) != 1; |
| 1275 | |
| 1276 | my $template = shift; |
| 1277 | |
| 1278 | my ($fh, $path, $errstr); |
| 1279 | croak "Error in mkstemp using $template: $errstr" |
| 1280 | unless (($fh, $path) = _gettemp($template, |
| 1281 | "open" => 1, |
| 1282 | "mkdir"=> 0 , |
| 1283 | "suffixlen" => 0, |
| 1284 | "ErrStr" => \$errstr, |
| 1285 | ) ); |
| 1286 | |
| 1287 | if (wantarray()) { |
| 1288 | return ($fh, $path); |
| 1289 | } else { |
| 1290 | return $fh; |
| 1291 | } |
| 1292 | |
| 1293 | } |
| 1294 | |
| 1295 | |
| 1296 | =item B<mkstemps> |
| 1297 | |
| 1298 | Similar to mkstemp(), except that an extra argument can be supplied |
| 1299 | with a suffix to be appended to the template. |
| 1300 | |
| 1301 | ($fh, $name) = mkstemps( $template, $suffix ); |
| 1302 | |
| 1303 | For example a template of C<testXXXXXX> and suffix of C<.dat> |
| 1304 | would generate a file similar to F<testhGji_w.dat>. |
| 1305 | |
| 1306 | Returns just the filehandle alone when called in scalar context. |
| 1307 | |
| 1308 | =cut |
| 1309 | |
| 1310 | sub mkstemps { |
| 1311 | |
| 1312 | croak "Usage: mkstemps(template, suffix)" |
| 1313 | if scalar(@_) != 2; |
| 1314 | |
| 1315 | |
| 1316 | my $template = shift; |
| 1317 | my $suffix = shift; |
| 1318 | |
| 1319 | $template .= $suffix; |
| 1320 | |
| 1321 | my ($fh, $path, $errstr); |
| 1322 | croak "Error in mkstemps using $template: $errstr" |
| 1323 | unless (($fh, $path) = _gettemp($template, |
| 1324 | "open" => 1, |
| 1325 | "mkdir"=> 0 , |
| 1326 | "suffixlen" => length($suffix), |
| 1327 | "ErrStr" => \$errstr, |
| 1328 | ) ); |
| 1329 | |
| 1330 | if (wantarray()) { |
| 1331 | return ($fh, $path); |
| 1332 | } else { |
| 1333 | return $fh; |
| 1334 | } |
| 1335 | |
| 1336 | } |
| 1337 | |
| 1338 | =item B<mkdtemp> |
| 1339 | |
| 1340 | Create a directory from a template. The template must end in |
| 1341 | X's that are replaced by the routine. |
| 1342 | |
| 1343 | $tmpdir_name = mkdtemp($template); |
| 1344 | |
| 1345 | Returns the name of the temporary directory created. |
| 1346 | Returns undef on failure. |
| 1347 | |
| 1348 | Directory must be removed by the caller. |
| 1349 | |
| 1350 | =cut |
| 1351 | |
| 1352 | #' # for emacs |
| 1353 | |
| 1354 | sub mkdtemp { |
| 1355 | |
| 1356 | croak "Usage: mkdtemp(template)" |
| 1357 | if scalar(@_) != 1; |
| 1358 | |
| 1359 | my $template = shift; |
| 1360 | my $suffixlen = 0; |
| 1361 | if ($^O eq 'VMS') { # dir names can end in delimiters |
| 1362 | $template =~ m/([\.\]:>]+)$/; |
| 1363 | $suffixlen = length($1); |
| 1364 | } |
| 1365 | if ( ($^O eq 'MacOS') && (substr($template, -1) eq ':') ) { |
| 1366 | # dir name has a trailing ':' |
| 1367 | ++$suffixlen; |
| 1368 | } |
| 1369 | my ($junk, $tmpdir, $errstr); |
| 1370 | croak "Error creating temp directory from template $template\: $errstr" |
| 1371 | unless (($junk, $tmpdir) = _gettemp($template, |
| 1372 | "open" => 0, |
| 1373 | "mkdir"=> 1 , |
| 1374 | "suffixlen" => $suffixlen, |
| 1375 | "ErrStr" => \$errstr, |
| 1376 | ) ); |
| 1377 | |
| 1378 | return $tmpdir; |
| 1379 | |
| 1380 | } |
| 1381 | |
| 1382 | =item B<mktemp> |
| 1383 | |
| 1384 | Returns a valid temporary filename but does not guarantee |
| 1385 | that the file will not be opened by someone else. |
| 1386 | |
| 1387 | $unopened_file = mktemp($template); |
| 1388 | |
| 1389 | Template is the same as that required by mkstemp(). |
| 1390 | |
| 1391 | =cut |
| 1392 | |
| 1393 | sub mktemp { |
| 1394 | |
| 1395 | croak "Usage: mktemp(template)" |
| 1396 | if scalar(@_) != 1; |
| 1397 | |
| 1398 | my $template = shift; |
| 1399 | |
| 1400 | my ($tmpname, $junk, $errstr); |
| 1401 | croak "Error getting name to temp file from template $template: $errstr" |
| 1402 | unless (($junk, $tmpname) = _gettemp($template, |
| 1403 | "open" => 0, |
| 1404 | "mkdir"=> 0 , |
| 1405 | "suffixlen" => 0, |
| 1406 | "ErrStr" => \$errstr, |
| 1407 | ) ); |
| 1408 | |
| 1409 | return $tmpname; |
| 1410 | } |
| 1411 | |
| 1412 | =back |
| 1413 | |
| 1414 | =head1 POSIX FUNCTIONS |
| 1415 | |
| 1416 | This section describes the re-implementation of the tmpnam() |
| 1417 | and tmpfile() functions described in L<POSIX> |
| 1418 | using the mkstemp() from this module. |
| 1419 | |
| 1420 | Unlike the L<POSIX|POSIX> implementations, the directory used |
| 1421 | for the temporary file is not specified in a system include |
| 1422 | file (C<P_tmpdir>) but simply depends on the choice of tmpdir() |
| 1423 | returned by L<File::Spec|File::Spec>. On some implementations this |
| 1424 | location can be set using the C<TMPDIR> environment variable, which |
| 1425 | may not be secure. |
| 1426 | If this is a problem, simply use mkstemp() and specify a template. |
| 1427 | |
| 1428 | =over 4 |
| 1429 | |
| 1430 | =item B<tmpnam> |
| 1431 | |
| 1432 | When called in scalar context, returns the full name (including path) |
| 1433 | of a temporary file (uses mktemp()). The only check is that the file does |
| 1434 | not already exist, but there is no guarantee that that condition will |
| 1435 | continue to apply. |
| 1436 | |
| 1437 | $file = tmpnam(); |
| 1438 | |
| 1439 | When called in list context, a filehandle to the open file and |
| 1440 | a filename are returned. This is achieved by calling mkstemp() |
| 1441 | after constructing a suitable template. |
| 1442 | |
| 1443 | ($fh, $file) = tmpnam(); |
| 1444 | |
| 1445 | If possible, this form should be used to prevent possible |
| 1446 | race conditions. |
| 1447 | |
| 1448 | See L<File::Spec/tmpdir> for information on the choice of temporary |
| 1449 | directory for a particular operating system. |
| 1450 | |
| 1451 | =cut |
| 1452 | |
| 1453 | sub tmpnam { |
| 1454 | |
| 1455 | # Retrieve the temporary directory name |
| 1456 | my $tmpdir = File::Spec->tmpdir; |
| 1457 | |
| 1458 | croak "Error temporary directory is not writable" |
| 1459 | if $tmpdir eq ''; |
| 1460 | |
| 1461 | # Use a ten character template and append to tmpdir |
| 1462 | my $template = File::Spec->catfile($tmpdir, TEMPXXX); |
| 1463 | |
| 1464 | if (wantarray() ) { |
| 1465 | return mkstemp($template); |
| 1466 | } else { |
| 1467 | return mktemp($template); |
| 1468 | } |
| 1469 | |
| 1470 | } |
| 1471 | |
| 1472 | =item B<tmpfile> |
| 1473 | |
| 1474 | In scalar context, returns the filehandle of a temporary file. |
| 1475 | |
| 1476 | $fh = tmpfile(); |
| 1477 | |
| 1478 | The file is removed when the filehandle is closed or when the program |
| 1479 | exits. No access to the filename is provided. |
| 1480 | |
| 1481 | If the temporary file can not be created undef is returned. |
| 1482 | Currently this command will probably not work when the temporary |
| 1483 | directory is on an NFS file system. |
| 1484 | |
| 1485 | =cut |
| 1486 | |
| 1487 | sub tmpfile { |
| 1488 | |
| 1489 | # Simply call tmpnam() in a list context |
| 1490 | my ($fh, $file) = tmpnam(); |
| 1491 | |
| 1492 | # Make sure file is removed when filehandle is closed |
| 1493 | # This will fail on NFS |
| 1494 | unlink0($fh, $file) |
| 1495 | or return undef; |
| 1496 | |
| 1497 | return $fh; |
| 1498 | |
| 1499 | } |
| 1500 | |
| 1501 | =back |
| 1502 | |
| 1503 | =head1 ADDITIONAL FUNCTIONS |
| 1504 | |
| 1505 | These functions are provided for backwards compatibility |
| 1506 | with common tempfile generation C library functions. |
| 1507 | |
| 1508 | They are not exported and must be addressed using the full package |
| 1509 | name. |
| 1510 | |
| 1511 | =over 4 |
| 1512 | |
| 1513 | =item B<tempnam> |
| 1514 | |
| 1515 | Return the name of a temporary file in the specified directory |
| 1516 | using a prefix. The file is guaranteed not to exist at the time |
| 1517 | the function was called, but such guarantees are good for one |
| 1518 | clock tick only. Always use the proper form of C<sysopen> |
| 1519 | with C<O_CREAT | O_EXCL> if you must open such a filename. |
| 1520 | |
| 1521 | $filename = File::Temp::tempnam( $dir, $prefix ); |
| 1522 | |
| 1523 | Equivalent to running mktemp() with $dir/$prefixXXXXXXXX |
| 1524 | (using unix file convention as an example) |
| 1525 | |
| 1526 | Because this function uses mktemp(), it can suffer from race conditions. |
| 1527 | |
| 1528 | =cut |
| 1529 | |
| 1530 | sub tempnam { |
| 1531 | |
| 1532 | croak 'Usage tempnam($dir, $prefix)' unless scalar(@_) == 2; |
| 1533 | |
| 1534 | my ($dir, $prefix) = @_; |
| 1535 | |
| 1536 | # Add a string to the prefix |
| 1537 | $prefix .= 'XXXXXXXX'; |
| 1538 | |
| 1539 | # Concatenate the directory to the file |
| 1540 | my $template = File::Spec->catfile($dir, $prefix); |
| 1541 | |
| 1542 | return mktemp($template); |
| 1543 | |
| 1544 | } |
| 1545 | |
| 1546 | =back |
| 1547 | |
| 1548 | =head1 UTILITY FUNCTIONS |
| 1549 | |
| 1550 | Useful functions for dealing with the filehandle and filename. |
| 1551 | |
| 1552 | =over 4 |
| 1553 | |
| 1554 | =item B<unlink0> |
| 1555 | |
| 1556 | Given an open filehandle and the associated filename, make a safe |
| 1557 | unlink. This is achieved by first checking that the filename and |
| 1558 | filehandle initially point to the same file and that the number of |
| 1559 | links to the file is 1 (all fields returned by stat() are compared). |
| 1560 | Then the filename is unlinked and the filehandle checked once again to |
| 1561 | verify that the number of links on that file is now 0. This is the |
| 1562 | closest you can come to making sure that the filename unlinked was the |
| 1563 | same as the file whose descriptor you hold. |
| 1564 | |
| 1565 | unlink0($fh, $path) or die "Error unlinking file $path safely"; |
| 1566 | |
| 1567 | Returns false on error. The filehandle is not closed since on some |
| 1568 | occasions this is not required. |
| 1569 | |
| 1570 | On some platforms, for example Windows NT, it is not possible to |
| 1571 | unlink an open file (the file must be closed first). On those |
| 1572 | platforms, the actual unlinking is deferred until the program ends and |
| 1573 | good status is returned. A check is still performed to make sure that |
| 1574 | the filehandle and filename are pointing to the same thing (but not at |
| 1575 | the time the end block is executed since the deferred removal may not |
| 1576 | have access to the filehandle). |
| 1577 | |
| 1578 | Additionally, on Windows NT not all the fields returned by stat() can |
| 1579 | be compared. For example, the C<dev> and C<rdev> fields seem to be |
| 1580 | different. Also, it seems that the size of the file returned by stat() |
| 1581 | does not always agree, with C<stat(FH)> being more accurate than |
| 1582 | C<stat(filename)>, presumably because of caching issues even when |
| 1583 | using autoflush (this is usually overcome by waiting a while after |
| 1584 | writing to the tempfile before attempting to C<unlink0> it). |
| 1585 | |
| 1586 | Finally, on NFS file systems the link count of the file handle does |
| 1587 | not always go to zero immediately after unlinking. Currently, this |
| 1588 | command is expected to fail on NFS disks. |
| 1589 | |
| 1590 | =cut |
| 1591 | |
| 1592 | sub unlink0 { |
| 1593 | |
| 1594 | croak 'Usage: unlink0(filehandle, filename)' |
| 1595 | unless scalar(@_) == 2; |
| 1596 | |
| 1597 | # Read args |
| 1598 | my ($fh, $path) = @_; |
| 1599 | |
| 1600 | warn "Unlinking $path using unlink0\n" |
| 1601 | if $DEBUG; |
| 1602 | |
| 1603 | # Stat the filehandle |
| 1604 | my @fh = stat $fh; |
| 1605 | |
| 1606 | if ($fh[3] > 1 && $^W) { |
| 1607 | carp "unlink0: fstat found too many links; SB=@fh" if $^W; |
| 1608 | } |
| 1609 | |
| 1610 | # Stat the path |
| 1611 | my @path = stat $path; |
| 1612 | |
| 1613 | unless (@path) { |
| 1614 | carp "unlink0: $path is gone already" if $^W; |
| 1615 | return; |
| 1616 | } |
| 1617 | |
| 1618 | # this is no longer a file, but may be a directory, or worse |
| 1619 | unless (-f _) { |
| 1620 | confess "panic: $path is no longer a file: SB=@fh"; |
| 1621 | } |
| 1622 | |
| 1623 | # Do comparison of each member of the array |
| 1624 | # On WinNT dev and rdev seem to be different |
| 1625 | # depending on whether it is a file or a handle. |
| 1626 | # Cannot simply compare all members of the stat return |
| 1627 | # Select the ones we can use |
| 1628 | my @okstat = (0..$#fh); # Use all by default |
| 1629 | if ($^O eq 'MSWin32') { |
| 1630 | @okstat = (1,2,3,4,5,7,8,9,10); |
| 1631 | } elsif ($^O eq 'os2') { |
| 1632 | @okstat = (0, 2..$#fh); |
| 1633 | } elsif ($^O eq 'VMS') { # device and file ID are sufficient |
| 1634 | @okstat = (0, 1); |
| 1635 | } elsif ($^O eq 'dos') { |
| 1636 | @okstat = (0,2..7,11..$#fh); |
| 1637 | } |
| 1638 | |
| 1639 | # Now compare each entry explicitly by number |
| 1640 | for (@okstat) { |
| 1641 | print "Comparing: $_ : $fh[$_] and $path[$_]\n" if $DEBUG; |
| 1642 | # Use eq rather than == since rdev, blksize, and blocks (6, 11, |
| 1643 | # and 12) will be '' on platforms that do not support them. This |
| 1644 | # is fine since we are only comparing integers. |
| 1645 | unless ($fh[$_] eq $path[$_]) { |
| 1646 | warn "Did not match $_ element of stat\n" if $DEBUG; |
| 1647 | return 0; |
| 1648 | } |
| 1649 | } |
| 1650 | |
| 1651 | # attempt remove the file (does not work on some platforms) |
| 1652 | if (_can_unlink_opened_file()) { |
| 1653 | # XXX: do *not* call this on a directory; possible race |
| 1654 | # resulting in recursive removal |
| 1655 | croak "unlink0: $path has become a directory!" if -d $path; |
| 1656 | unlink($path) or return 0; |
| 1657 | |
| 1658 | # Stat the filehandle |
| 1659 | @fh = stat $fh; |
| 1660 | |
| 1661 | print "Link count = $fh[3] \n" if $DEBUG; |
| 1662 | |
| 1663 | # Make sure that the link count is zero |
| 1664 | # - Cygwin provides deferred unlinking, however, |
| 1665 | # on Win9x the link count remains 1 |
| 1666 | # On NFS the link count may still be 1 but we cant know that |
| 1667 | # we are on NFS |
| 1668 | return ( $fh[3] == 0 or $^O eq 'cygwin' ? 1 : 0); |
| 1669 | |
| 1670 | } else { |
| 1671 | _deferred_unlink($fh, $path, 0); |
| 1672 | return 1; |
| 1673 | } |
| 1674 | |
| 1675 | } |
| 1676 | |
| 1677 | =back |
| 1678 | |
| 1679 | =head1 PACKAGE VARIABLES |
| 1680 | |
| 1681 | These functions control the global state of the package. |
| 1682 | |
| 1683 | =over 4 |
| 1684 | |
| 1685 | =item B<safe_level> |
| 1686 | |
| 1687 | Controls the lengths to which the module will go to check the safety of the |
| 1688 | temporary file or directory before proceeding. |
| 1689 | Options are: |
| 1690 | |
| 1691 | =over 8 |
| 1692 | |
| 1693 | =item STANDARD |
| 1694 | |
| 1695 | Do the basic security measures to ensure the directory exists and |
| 1696 | is writable, that the umask() is fixed before opening of the file, |
| 1697 | that temporary files are opened only if they do not already exist, and |
| 1698 | that possible race conditions are avoided. Finally the L<unlink0|"unlink0"> |
| 1699 | function is used to remove files safely. |
| 1700 | |
| 1701 | =item MEDIUM |
| 1702 | |
| 1703 | In addition to the STANDARD security, the output directory is checked |
| 1704 | to make sure that it is owned either by root or the user running the |
| 1705 | program. If the directory is writable by group or by other, it is then |
| 1706 | checked to make sure that the sticky bit is set. |
| 1707 | |
| 1708 | Will not work on platforms that do not support the C<-k> test |
| 1709 | for sticky bit. |
| 1710 | |
| 1711 | =item HIGH |
| 1712 | |
| 1713 | In addition to the MEDIUM security checks, also check for the |
| 1714 | possibility of ``chown() giveaway'' using the L<POSIX|POSIX> |
| 1715 | sysconf() function. If this is a possibility, each directory in the |
| 1716 | path is checked in turn for safeness, recursively walking back to the |
| 1717 | root directory. |
| 1718 | |
| 1719 | For platforms that do not support the L<POSIX|POSIX> |
| 1720 | C<_PC_CHOWN_RESTRICTED> symbol (for example, Windows NT) it is |
| 1721 | assumed that ``chown() giveaway'' is possible and the recursive test |
| 1722 | is performed. |
| 1723 | |
| 1724 | =back |
| 1725 | |
| 1726 | The level can be changed as follows: |
| 1727 | |
| 1728 | File::Temp->safe_level( File::Temp::HIGH ); |
| 1729 | |
| 1730 | The level constants are not exported by the module. |
| 1731 | |
| 1732 | Currently, you must be running at least perl v5.6.0 in order to |
| 1733 | run with MEDIUM or HIGH security. This is simply because the |
| 1734 | safety tests use functions from L<Fcntl|Fcntl> that are not |
| 1735 | available in older versions of perl. The problem is that the version |
| 1736 | number for Fcntl is the same in perl 5.6.0 and in 5.005_03 even though |
| 1737 | they are different versions. |
| 1738 | |
| 1739 | On systems that do not support the HIGH or MEDIUM safety levels |
| 1740 | (for example Win NT or OS/2) any attempt to change the level will |
| 1741 | be ignored. The decision to ignore rather than raise an exception |
| 1742 | allows portable programs to be written with high security in mind |
| 1743 | for the systems that can support this without those programs failing |
| 1744 | on systems where the extra tests are irrelevant. |
| 1745 | |
| 1746 | If you really need to see whether the change has been accepted |
| 1747 | simply examine the return value of C<safe_level>. |
| 1748 | |
| 1749 | $newlevel = File::Temp->safe_level( File::Temp::HIGH ); |
| 1750 | die "Could not change to high security" |
| 1751 | if $newlevel != File::Temp::HIGH; |
| 1752 | |
| 1753 | =cut |
| 1754 | |
| 1755 | { |
| 1756 | # protect from using the variable itself |
| 1757 | my $LEVEL = STANDARD; |
| 1758 | sub safe_level { |
| 1759 | my $self = shift; |
| 1760 | if (@_) { |
| 1761 | my $level = shift; |
| 1762 | if (($level != STANDARD) && ($level != MEDIUM) && ($level != HIGH)) { |
| 1763 | carp "safe_level: Specified level ($level) not STANDARD, MEDIUM or HIGH - ignoring\n" if $^W; |
| 1764 | } else { |
| 1765 | # Dont allow this on perl 5.005 or earlier |
| 1766 | if ($] < 5.006 && $level != STANDARD) { |
| 1767 | # Cant do MEDIUM or HIGH checks |
| 1768 | croak "Currently requires perl 5.006 or newer to do the safe checks"; |
| 1769 | } |
| 1770 | # Check that we are allowed to change level |
| 1771 | # Silently ignore if we can not. |
| 1772 | $LEVEL = $level if _can_do_level($level); |
| 1773 | } |
| 1774 | } |
| 1775 | return $LEVEL; |
| 1776 | } |
| 1777 | } |
| 1778 | |
| 1779 | =item TopSystemUID |
| 1780 | |
| 1781 | This is the highest UID on the current system that refers to a root |
| 1782 | UID. This is used to make sure that the temporary directory is |
| 1783 | owned by a system UID (C<root>, C<bin>, C<sys> etc) rather than |
| 1784 | simply by root. |
| 1785 | |
| 1786 | This is required since on many unix systems C</tmp> is not owned |
| 1787 | by root. |
| 1788 | |
| 1789 | Default is to assume that any UID less than or equal to 10 is a root |
| 1790 | UID. |
| 1791 | |
| 1792 | File::Temp->top_system_uid(10); |
| 1793 | my $topid = File::Temp->top_system_uid; |
| 1794 | |
| 1795 | This value can be adjusted to reduce security checking if required. |
| 1796 | The value is only relevant when C<safe_level> is set to MEDIUM or higher. |
| 1797 | |
| 1798 | =back |
| 1799 | |
| 1800 | =cut |
| 1801 | |
| 1802 | { |
| 1803 | my $TopSystemUID = 10; |
| 1804 | sub top_system_uid { |
| 1805 | my $self = shift; |
| 1806 | if (@_) { |
| 1807 | my $newuid = shift; |
| 1808 | croak "top_system_uid: UIDs should be numeric" |
| 1809 | unless $newuid =~ /^\d+$/s; |
| 1810 | $TopSystemUID = $newuid; |
| 1811 | } |
| 1812 | return $TopSystemUID; |
| 1813 | } |
| 1814 | } |
| 1815 | |
| 1816 | =head1 WARNING |
| 1817 | |
| 1818 | For maximum security, endeavour always to avoid ever looking at, |
| 1819 | touching, or even imputing the existence of the filename. You do not |
| 1820 | know that that filename is connected to the same file as the handle |
| 1821 | you have, and attempts to check this can only trigger more race |
| 1822 | conditions. It's far more secure to use the filehandle alone and |
| 1823 | dispense with the filename altogether. |
| 1824 | |
| 1825 | If you need to pass the handle to something that expects a filename |
| 1826 | then, on a unix system, use C<"/dev/fd/" . fileno($fh)> for arbitrary |
| 1827 | programs, or more generally C<< "+<=&" . fileno($fh) >> for Perl |
| 1828 | programs. You will have to clear the close-on-exec bit on that file |
| 1829 | descriptor before passing it to another process. |
| 1830 | |
| 1831 | use Fcntl qw/F_SETFD F_GETFD/; |
| 1832 | fcntl($tmpfh, F_SETFD, 0) |
| 1833 | or die "Can't clear close-on-exec flag on temp fh: $!\n"; |
| 1834 | |
| 1835 | =head2 Temporary files and NFS |
| 1836 | |
| 1837 | Some problems are associated with using temporary files that reside |
| 1838 | on NFS file systems and it is recommended that a local filesystem |
| 1839 | is used whenever possible. Some of the security tests will most probably |
| 1840 | fail when the temp file is not local. Additionally, be aware that |
| 1841 | the performance of I/O operations over NFS will not be as good as for |
| 1842 | a local disk. |
| 1843 | |
| 1844 | =head1 HISTORY |
| 1845 | |
| 1846 | Originally began life in May 1999 as an XS interface to the system |
| 1847 | mkstemp() function. In March 2000, the OpenBSD mkstemp() code was |
| 1848 | translated to Perl for total control of the code's |
| 1849 | security checking, to ensure the presence of the function regardless of |
| 1850 | operating system and to help with portability. |
| 1851 | |
| 1852 | =head1 SEE ALSO |
| 1853 | |
| 1854 | L<POSIX/tmpnam>, L<POSIX/tmpfile>, L<File::Spec>, L<File::Path> |
| 1855 | |
| 1856 | See L<IO::File> and L<File::MkTemp> for different implementations of |
| 1857 | temporary file handling. |
| 1858 | |
| 1859 | =head1 AUTHOR |
| 1860 | |
| 1861 | Tim Jenness E<lt>t.jenness@jach.hawaii.eduE<gt> |
| 1862 | |
| 1863 | Copyright (C) 1999-2001 Tim Jenness and the UK Particle Physics and |
| 1864 | Astronomy Research Council. All Rights Reserved. This program is free |
| 1865 | software; you can redistribute it and/or modify it under the same |
| 1866 | terms as Perl itself. |
| 1867 | |
| 1868 | Original Perl implementation loosely based on the OpenBSD C code for |
| 1869 | mkstemp(). Thanks to Tom Christiansen for suggesting that this module |
| 1870 | should be written and providing ideas for code improvements and |
| 1871 | security enhancements. |
| 1872 | |
| 1873 | =cut |
| 1874 | |
| 1875 | |
| 1876 | 1; |