1 .\"- 2 .\" Copyright (c) 1992 Keith Muller. 3 .\" Copyright (c) 1992, 1993 4 .\" The Regents of the University of California. All rights reserved. 5 .\" 6 .\" This code is derived from software contributed to Berkeley by 7 .\" Keith Muller of the University of California, San Diego. 8 .\" 9 .\" Redistribution and use in source and binary forms, with or without 10 .\" modification, are permitted provided that the following conditions 11 .\" are met: 12 .\" 1. Redistributions of source code must retain the above copyright 13 .\" notice, this list of conditions and the following disclaimer. 14 .\" 2. Redistributions in binary form must reproduce the above copyright 15 .\" notice, this list of conditions and the following disclaimer in the 16 .\" documentation and/or other materials provided with the distribution. 17 .\" 4. Neither the name of the University nor the names of its contributors 18 .\" may be used to endorse or promote products derived from this software 19 .\" without specific prior written permission. 20 .\" 21 .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 .\" SUCH DAMAGE. 32 .\" 33 .\" @(#)pax.1 8.4 (Berkeley) 4/18/94 34 .\" $FreeBSD$ 35 .\" 36 .Dd March 17, 2015 37 .Dt PAX 1 38 .Os 39 .Sh NAME 40 .Nm pax 41 .Nd read and write file archives and copy directory hierarchies 42 .Sh SYNOPSIS 43 .Nm 44 .Op Fl cdnvzO 45 .Bk -words 46 .Op Fl f Ar archive 47 .Ek 48 .Bk -words 49 .Op Fl s Ar replstr 50 .Ar ...\& 51 .Ek 52 .Bk -words 53 .Op Fl U Ar user 54 .Ar ...\& 55 .Ek 56 .Bk -words 57 .Op Fl G Ar group 58 .Ar ...\& 59 .Ek 60 .Bk -words 61 .Oo 62 .Fl T 63 .Op Ar from_date 64 .Op Ar ,to_date 65 .Oc 66 .Ar ...\& 67 .Ek 68 .Op Ar pattern ...\& 69 .Nm 70 .Fl r 71 .Op Fl cdiknuvzDOYZ 72 .Bk -words 73 .Op Fl f Ar archive 74 .Ek 75 .Bk -words 76 .Op Fl o Ar options 77 .Ar ...\& 78 .Ek 79 .Bk -words 80 .Op Fl p Ar string 81 .Ar ...\& 82 .Ek 83 .Bk -words 84 .Op Fl s Ar replstr 85 .Ar ...\& 86 .Ek 87 .Op Fl E Ar limit 88 .Bk -words 89 .Op Fl U Ar user 90 .Ar ...\& 91 .Ek 92 .Bk -words 93 .Op Fl G Ar group 94 .Ar ...\& 95 .Ek 96 .Bk -words 97 .Oo 98 .Fl T 99 .Op Ar from_date 100 .Op Ar ,to_date 101 .Oc 102 .Ar ...\& 103 .Ek 104 .Op Ar pattern ...\& 105 .Nm 106 .Fl w 107 .Op Fl dituvzHLOPX 108 .Bk -words 109 .Op Fl b Ar blocksize 110 .Ek 111 .Oo 112 .Op Fl a 113 .Op Fl f Ar archive 114 .Oc 115 .Bk -words 116 .Op Fl x Ar format 117 .Ek 118 .Bk -words 119 .Op Fl s Ar replstr 120 .Ar ...\& 121 .Ek 122 .Bk -words 123 .Op Fl o Ar options 124 .Ar ...\& 125 .Ek 126 .Bk -words 127 .Op Fl U Ar user 128 .Ar ...\& 129 .Ek 130 .Bk -words 131 .Op Fl G Ar group 132 .Ar ...\& 133 .Ek 134 .Bk -words 135 .Op Fl B Ar bytes 136 .Ek 137 .Bk -words 138 .Oo 139 .Fl T 140 .Op Ar from_date 141 .Op Ar ,to_date 142 .Op Ar /[c][m] 143 .Oc 144 .Ar ...\& 145 .Ek 146 .Op Ar 147 .Nm 148 .Fl r 149 .Fl w 150 .Op Fl diklntuvDHLOPXYZ 151 .Bk -words 152 .Op Fl p Ar string 153 .Ar ...\& 154 .Ek 155 .Bk -words 156 .Op Fl s Ar replstr 157 .Ar ...\& 158 .Ek 159 .Bk -words 160 .Op Fl U Ar user 161 .Ar ...\& 162 .Ek 163 .Bk -words 164 .Op Fl G Ar group 165 .Ar ...\& 166 .Ek 167 .Bk -words 168 .Oo 169 .Fl T 170 .Op Ar from_date 171 .Op Ar ,to_date 172 .Op Ar /[c][m] 173 .Oc 174 .Ar ...\& 175 .Ek 176 .Op Ar 177 .Ar directory 178 .Sh DESCRIPTION 179 The 180 .Nm 181 utility will read, write, and list the members of an archive file, 182 and will copy directory hierarchies. 183 These operations are independent of the specific archive format, 184 and support a wide variety of different archive formats. 185 A list of supported archive formats can be found under the description of the 186 .Fl x 187 option. 188 .Pp 189 The presence of the 190 .Fl r 191 and the 192 .Fl w 193 options specifies which of the following functional modes 194 .Nm 195 will operate under: 196 .Em list , read , write , 197 and 198 .Em copy . 199 .Bl -tag -width 6n 200 .It <none> 201 .Em List . 202 Write to 203 .Dv standard output 204 a table of contents of the members of the archive file read from 205 .Dv standard input , 206 whose pathnames match the specified 207 .Ar patterns . 208 The table of contents contains one filename per line 209 and is written using single line buffering. 210 .It Fl r 211 .Em Read . 212 Extract the members of the archive file read from the 213 .Dv standard input , 214 with pathnames matching the specified 215 .Ar patterns . 216 The archive format and blocking is automatically determined on input. 217 When an extracted file is a directory, the entire file hierarchy 218 rooted at that directory is extracted. 219 All extracted files are created relative to the current file hierarchy. 220 The setting of ownership, access and modification times, and file mode of 221 the extracted files are discussed in more detail under the 222 .Fl p 223 option. 224 .It Fl w 225 .Em Write . 226 Write an archive containing the 227 .Ar file 228 operands to 229 .Dv standard output 230 using the specified archive format. 231 When no 232 .Ar file 233 operands are specified, a list of files to copy with one per line is read from 234 .Dv standard input . 235 When a 236 .Ar file 237 operand is also a directory, the entire file hierarchy rooted 238 at that directory will be included. 239 .It Fl r Fl w 240 .Em Copy . 241 Copy the 242 .Ar file 243 operands to the destination 244 .Ar directory . 245 When no 246 .Ar file 247 operands are specified, a list of files to copy with one per line is read from 248 the 249 .Dv standard input . 250 When a 251 .Ar file 252 operand is also a directory the entire file 253 hierarchy rooted at that directory will be included. 254 The effect of the 255 .Em copy 256 is as if the copied files were written to an archive file and then 257 subsequently extracted, except that there may be hard links between 258 the original and the copied files (see the 259 .Fl l 260 option below). 261 .Pp 262 .Em Warning : 263 The destination 264 .Ar directory 265 must not be one of the 266 .Ar file 267 operands or a member of a file hierarchy rooted at one of the 268 .Ar file 269 operands. 270 The result of a 271 .Em copy 272 under these conditions is unpredictable. 273 .El 274 .Pp 275 While processing a damaged archive during a 276 .Em read 277 or 278 .Em list 279 operation, 280 .Nm 281 will attempt to recover from media defects and will search through the archive 282 to locate and process the largest number of archive members possible (see the 283 .Fl E 284 option for more details on error handling). 285 .Sh OPERANDS 286 The 287 .Ar directory 288 operand specifies a destination directory pathname. 289 If the 290 .Ar directory 291 operand does not exist, or it is not writable by the user, 292 or it is not of type directory, 293 .Nm 294 will exit with a non-zero exit status. 295 .Pp 296 The 297 .Ar pattern 298 operand is used to select one or more pathnames of archive members. 299 Archive members are selected using the pattern matching notation described 300 by 301 .Xr fnmatch 3 . 302 When the 303 .Ar pattern 304 operand is not supplied, all members of the archive will be selected. 305 When a 306 .Ar pattern 307 matches a directory, the entire file hierarchy rooted at that directory will 308 be selected. 309 When a 310 .Ar pattern 311 operand does not select at least one archive member, 312 .Nm 313 will write these 314 .Ar pattern 315 operands in a diagnostic message to 316 .Dv standard error 317 and then exit with a non-zero exit status. 318 .Pp 319 The 320 .Ar file 321 operand specifies the pathname of a file to be copied or archived. 322 When a 323 .Ar file 324 operand does not select at least one archive member, 325 .Nm 326 will write these 327 .Ar file 328 operand pathnames in a diagnostic message to 329 .Dv standard error 330 and then exit with a non-zero exit status. 331 .Sh OPTIONS 332 The following options are supported: 333 .Bl -tag -width 4n 334 .It Fl r 335 Read an archive file from 336 .Dv standard input 337 and extract the specified 338 .Ar files . 339 If any intermediate directories are needed in order to extract an archive 340 member, these directories will be created as if 341 .Xr mkdir 2 342 was called with the bitwise inclusive 343 .Dv OR 344 of 345 .Dv S_IRWXU , S_IRWXG , 346 and 347 .Dv S_IRWXO 348 as the mode argument. 349 When the selected archive format supports the specification of linked 350 files and these files cannot be linked while the archive is being extracted, 351 .Nm 352 will write a diagnostic message to 353 .Dv standard error 354 and exit with a non-zero exit status at the completion of operation. 355 .It Fl w 356 Write files to the 357 .Dv standard output 358 in the specified archive format. 359 When no 360 .Ar file 361 operands are specified, 362 .Dv standard input 363 is read for a list of pathnames with one per line without any leading or 364 trailing 365 .Aq blanks . 366 .It Fl a 367 Append 368 .Ar files 369 to the end of an archive that was previously written. 370 If an archive format is not specified with a 371 .Fl x 372 option, the format currently being used in the archive will be selected. 373 Any attempt to append to an archive in a format different from the 374 format already used in the archive will cause 375 .Nm 376 to exit immediately 377 with a non-zero exit status. 378 The blocking size used in the archive volume where writing starts 379 will continue to be used for the remainder of that archive volume. 380 .Pp 381 .Em Warning : 382 Many storage devices are not able to support the operations necessary 383 to perform an append operation. 384 Any attempt to append to an archive stored on such a device may damage the 385 archive or have other unpredictable results. 386 Tape drives in particular are more likely to not support an append operation. 387 An archive stored in a regular file system file or on a disk device will 388 usually support an append operation. 389 .It Fl b Ar blocksize 390 When 391 .Em writing 392 an archive, 393 block the output at a positive decimal integer number of 394 bytes per write to the archive file. 395 The 396 .Ar blocksize 397 must be a multiple of 512 bytes with a maximum of 64512 bytes. 398 A 399 .Ar blocksize 400 larger than 32256 bytes violates the 401 .Tn POSIX 402 standard and will not be portable to all systems. 403 A 404 .Ar blocksize 405 can end with 406 .Li k 407 or 408 .Li b 409 to specify multiplication by 1024 (1K) or 512, respectively. 410 A pair of 411 .Ar blocksizes 412 can be separated by 413 .Li x 414 to indicate a product. 415 A specific archive device may impose additional restrictions on the size 416 of blocking it will support. 417 When blocking is not specified, the default 418 .Ar blocksize 419 is dependent on the specific archive format being used (see the 420 .Fl x 421 option). 422 .It Fl c 423 Match all file or archive members 424 .Em except 425 those specified by the 426 .Ar pattern 427 and 428 .Ar file 429 operands. 430 .It Fl d 431 Cause files of type directory being copied or archived, or archive members of 432 type directory being extracted, to match only the directory file or archive 433 member and not the file hierarchy rooted at the directory. 434 .It Fl f Ar archive 435 Specify 436 .Ar archive 437 as the pathname of the input or output archive, overriding the default 438 .Dv standard input 439 (for 440 .Em list 441 and 442 .Em read ) 443 or 444 .Dv standard output 445 (for 446 .Em write ) . 447 A single archive may span multiple files and different archive devices. 448 When required, 449 .Nm 450 will prompt for the pathname of the file or device of the next volume in the 451 archive. 452 .It Fl i 453 Interactively rename files or archive members. 454 For each archive member matching a 455 .Ar pattern 456 operand or each file matching a 457 .Ar file 458 operand, 459 .Nm 460 will prompt to 461 .Pa /dev/tty 462 giving the name of the file, its file mode and its modification time. 463 The 464 .Nm 465 utility will then read a line from 466 .Pa /dev/tty . 467 If this line is blank, the file or archive member is skipped. 468 If this line consists of a single period, the 469 file or archive member is processed with no modification to its name. 470 Otherwise, its name is replaced with the contents of the line. 471 The 472 .Nm 473 utility will immediately exit with a non-zero exit status if 474 .Dv <EOF> 475 is encountered when reading a response or if 476 .Pa /dev/tty 477 cannot be opened for reading and writing. 478 .It Fl k 479 Do not overwrite existing files. 480 .It Fl l 481 Link files. 482 (The letter ell). 483 In the 484 .Em copy 485 mode 486 .Pq Fl r w , 487 hard links are made between the source and destination file hierarchies 488 whenever possible. 489 .It Fl n 490 Select the first archive member that matches each 491 .Ar pattern 492 operand. 493 No more than one archive member is matched for each 494 .Ar pattern . 495 When members of type directory are matched, the file hierarchy rooted at that 496 directory is also matched (unless 497 .Fl d 498 is also specified). 499 .It Fl o Ar options 500 Information to modify the algorithm for extracting or writing archive files 501 which is specific to the archive format specified by 502 .Fl x . 503 In general, 504 .Ar options 505 take the form: 506 .Cm name=value 507 .It Fl p Ar string 508 Specify one or more file characteristic options (privileges). 509 The 510 .Ar string 511 option-argument is a string specifying file characteristics to be retained or 512 discarded on extraction. 513 The string consists of the specification characters 514 .Cm a , e , m , o , 515 and 516 .Cm p . 517 Multiple characteristics can be concatenated within the same string 518 and multiple 519 .Fl p 520 options can be specified. 521 The meaning of the specification characters are as follows: 522 .Bl -tag -width 2n 523 .It Cm a 524 Do not preserve file access times. 525 By default, file access times are preserved whenever possible. 526 .It Cm e 527 .Sq Preserve everything , 528 the user ID, group ID, file mode bits, 529 file access time, and file modification time. 530 This is intended to be used by 531 .Em root , 532 someone with all the appropriate privileges, in order to preserve all 533 aspects of the files as they are recorded in the archive. 534 The 535 .Cm e 536 flag is the sum of the 537 .Cm o 538 and 539 .Cm p 540 flags. 541 .It Cm m 542 Do not preserve file modification times. 543 By default, file modification times are preserved whenever possible. 544 .It Cm o 545 Preserve the user ID and group ID. 546 .It Cm p 547 .Sq Preserve 548 the file mode bits. 549 This intended to be used by a 550 .Em user 551 with regular privileges who wants to preserve all aspects of the file other 552 than the ownership. 553 The file times are preserved by default, but two other flags are offered to 554 disable this and use the time of extraction instead. 555 .El 556 .Pp 557 In the preceding list, 558 .Sq preserve 559 indicates that an attribute stored in the archive is given to the 560 extracted file, subject to the permissions of the invoking 561 process. 562 Otherwise the attribute of the extracted file is determined as 563 part of the normal file creation action. 564 If neither the 565 .Cm e 566 nor the 567 .Cm o 568 specification character is specified, or the user ID and group ID are not 569 preserved for any reason, 570 .Nm 571 will not set the 572 .Dv S_ISUID 573 .Em ( setuid ) 574 and 575 .Dv S_ISGID 576 .Em ( setgid ) 577 bits of the file mode. 578 If the preservation of any of these items fails for any reason, 579 .Nm 580 will write a diagnostic message to 581 .Dv standard error . 582 Failure to preserve these items will affect the final exit status, 583 but will not cause the extracted file to be deleted. 584 If the file characteristic letters in any of the string option-arguments are 585 duplicated or conflict with each other, the one(s) given last will take 586 precedence. 587 For example, if 588 .Dl Fl p Ar eme 589 is specified, file modification times are still preserved. 590 .Pp 591 File flags set by 592 .Xr chflags 1 593 are not understood by 594 .Nm , 595 however 596 .Xr tar 1 597 and 598 .Xr dump 8 599 will preserve these. 600 .It Fl s Ar replstr 601 Modify the file or archive member names specified by the 602 .Ar pattern 603 or 604 .Ar file 605 operands according to the substitution expression 606 .Ar replstr , 607 using the syntax of the 608 .Xr ed 1 609 utility regular expressions. 610 The format of these regular expressions are: 611 .Dl /old/new/[gp] 612 As in 613 .Xr ed 1 , 614 .Cm old 615 is a basic regular expression and 616 .Cm new 617 can contain an ampersand (&), \\n (where n is a digit) back-references, 618 or subexpression matching. 619 The 620 .Cm old 621 string may also contain 622 .Dv <newline> 623 characters. 624 Any non-null character can be used as a delimiter (/ is shown here). 625 Multiple 626 .Fl s 627 expressions can be specified. 628 The expressions are applied in the order they are specified on the 629 command line, terminating with the first successful substitution. 630 The optional trailing 631 .Cm g 632 continues to apply the substitution expression to the pathname substring 633 which starts with the first character following the end of the last successful 634 substitution. 635 The first unsuccessful substitution stops the operation of the 636 .Cm g 637 option. 638 The optional trailing 639 .Cm p 640 will cause the final result of a successful substitution to be written to 641 .Dv standard error 642 in the following format: 643 .Dl <original pathname> >> <new pathname> 644 File or archive member names that substitute to the empty string 645 are not selected and will be skipped. 646 .It Fl t 647 Reset the access times of any file or directory read or accessed by 648 .Nm 649 to be the same as they were before being read or accessed by 650 .Nm . 651 .It Fl u 652 Ignore files that are older (having a less recent file modification time) 653 than a pre-existing file or archive member with the same name. 654 During 655 .Em read , 656 an archive member with the same name as a file in the file system will be 657 extracted if the archive member is newer than the file. 658 During 659 .Em write , 660 a file system member with the same name as an archive member will be 661 written to the archive if it is newer than the archive member. 662 During 663 .Em copy , 664 the file in the destination hierarchy is replaced by the file in the source 665 hierarchy or by a link to the file in the source hierarchy if the file in 666 the source hierarchy is newer. 667 .It Fl v 668 During a 669 .Em list 670 operation, produce a verbose table of contents using the format of the 671 .Xr ls 1 672 utility with the 673 .Fl l 674 option. 675 For pathnames representing a hard link to a previous member of the archive, 676 the output has the format: 677 .Dl <ls -l listing> == <link name> 678 For pathnames representing a symbolic link, the output has the format: 679 .Dl <ls -l listing> => <link name> 680 Where <ls -l listing> is the output format specified by the 681 .Xr ls 1 682 utility when used with the 683 .Fl l 684 option. 685 Otherwise for all the other operational modes 686 .Em ( read , write , 687 and 688 .Em copy ) , 689 pathnames are written and flushed to 690 .Dv standard error 691 without a trailing 692 .Dv <newline> 693 as soon as processing begins on that file or 694 archive member. 695 The trailing 696 .Dv <newline> , 697 is not buffered, and is written only after the file has been read or written. 698 .It Fl x Ar format 699 Specify the output archive format, with the default format being 700 .Ar ustar . 701 The 702 .Nm 703 utility currently supports the following formats: 704 .Bl -tag -width "sv4cpio" 705 .It Ar cpio 706 The extended cpio interchange format specified in the 707 .St -p1003.2 708 standard. 709 The default blocksize for this format is 5120 bytes. 710 Inode and device information about a file (used for detecting file hard links 711 by this format) which may be truncated by this format is detected by 712 .Nm 713 and is repaired. 714 .It Ar bcpio 715 The old binary cpio format. 716 The default blocksize for this format is 5120 bytes. 717 This format is not very portable and should not be used when other formats 718 are available. 719 Inode and device information about a file (used for detecting file hard links 720 by this format) which may be truncated by this format is detected by 721 .Nm 722 and is repaired. 723 .It Ar sv4cpio 724 The System V release 4 cpio. 725 The default blocksize for this format is 5120 bytes. 726 Inode and device information about a file (used for detecting file hard links 727 by this format) which may be truncated by this format is detected by 728 .Nm 729 and is repaired. 730 .It Ar sv4crc 731 The System V release 4 cpio with file crc checksums. 732 The default blocksize for this format is 5120 bytes. 733 Inode and device information about a file (used for detecting file hard links 734 by this format) which may be truncated by this format is detected by 735 .Nm 736 and is repaired. 737 .It Ar tar 738 The old 739 .Bx 740 tar format as found in 741 .Bx 4.3 . 742 The default blocksize for this format is 10240 bytes. 743 Pathnames stored by this format must be 100 characters or less in length. 744 Only 745 .Em regular 746 files, 747 .Em hard links , soft links , 748 and 749 .Em directories 750 will be archived (other file system types are not supported). 751 For backwards compatibility with even older tar formats, a 752 .Fl o 753 option can be used when writing an archive to omit the storage of directories. 754 This option takes the form: 755 .Dl Fl o Cm write_opt=nodir 756 .It Ar ustar 757 The extended tar interchange format specified in the 758 .St -p1003.2 759 standard. 760 The default blocksize for this format is 10240 bytes. 761 Pathnames stored by this format must be 255 characters or less in length. 762 The directory part may be at most 155 characters and each path component 763 must be less than 100 characters. 764 .El 765 .Pp 766 The 767 .Nm 768 utility will detect and report any file that it is unable to store or extract 769 as the result of any specific archive format restrictions. 770 The individual archive formats may impose additional restrictions on use. 771 Typical archive format restrictions include (but are not limited to): 772 file pathname length, file size, link pathname length and the type of the file. 773 .It Fl z 774 Use 775 .Xr gzip 1 776 to compress (decompress) the archive while writing (reading). 777 Incompatible with 778 .Fl a . 779 .It Fl B Ar bytes 780 Limit the number of bytes written to a single archive volume to 781 .Ar bytes . 782 The 783 .Ar bytes 784 limit can end with 785 .Li m , 786 .Li k , 787 or 788 .Li b 789 to specify multiplication by 1048576 (1M), 1024 (1K) or 512, respectively. 790 A pair of 791 .Ar bytes 792 limits can be separated by 793 .Li x 794 to indicate a product. 795 .Pp 796 .Em Warning : 797 Only use this option when writing an archive to a device which supports 798 an end of file read condition based on last (or largest) write offset 799 (such as a regular file or a tape drive). 800 The use of this option with a floppy or hard disk is not recommended. 801 .It Fl D 802 This option is the same as the 803 .Fl u 804 option, except that the file inode change time is checked instead of the 805 file modification time. 806 The file inode change time can be used to select files whose inode information 807 (e.g.\& uid, gid, etc.) is newer than a copy of the file in the destination 808 .Ar directory . 809 .It Fl E Ar limit 810 Limit the number of consecutive read faults while trying to read a flawed 811 archives to 812 .Ar limit . 813 With a positive 814 .Ar limit , 815 .Nm 816 will attempt to recover from an archive read error and will 817 continue processing starting with the next file stored in the archive. 818 A 819 .Ar limit 820 of 0 will cause 821 .Nm 822 to stop operation after the first read error is detected on an archive volume. 823 A 824 .Ar limit 825 of 826 .Li NONE 827 will cause 828 .Nm 829 to attempt to recover from read errors forever. 830 The default 831 .Ar limit 832 is a small positive number of retries. 833 .Pp 834 .Em Warning : 835 Using this option with 836 .Li NONE 837 should be used with extreme caution as 838 .Nm 839 may get stuck in an infinite loop on a very badly flawed archive. 840 .It Fl G Ar group 841 Select a file based on its 842 .Ar group 843 name, or when starting with a 844 .Cm # , 845 a numeric gid. 846 A '\\' can be used to escape the 847 .Cm # . 848 Multiple 849 .Fl G 850 options may be supplied and checking stops with the first match. 851 .It Fl H 852 Follow only command line symbolic links while performing a physical file 853 system traversal. 854 .It Fl L 855 Follow all symbolic links to perform a logical file system traversal. 856 .It Fl O 857 Force the archive to be one volume. 858 If a volume ends prematurely, 859 .Nm 860 will not prompt for a new volume. 861 This option can be useful for 862 automated tasks where error recovery cannot be performed by a human. 863 .It Fl P 864 Do not follow symbolic links, perform a physical file system traversal. 865 This is the default mode. 866 .It Fl T Ar [from_date][,to_date][/[c][m]] 867 Allow files to be selected based on a file modification or inode change 868 time falling within a specified time range of 869 .Ar from_date 870 to 871 .Ar to_date 872 (the dates are inclusive). 873 If only a 874 .Ar from_date 875 is supplied, all files with a modification or inode change time 876 equal to or younger are selected. 877 If only a 878 .Ar to_date 879 is supplied, all files with a modification or inode change time 880 equal to or older will be selected. 881 When the 882 .Ar from_date 883 is equal to the 884 .Ar to_date , 885 only files with a modification or inode change time of exactly that 886 time will be selected. 887 .Pp 888 When 889 .Nm 890 is in the 891 .Em write 892 or 893 .Em copy 894 mode, the optional trailing field 895 .Ar [c][m] 896 can be used to determine which file time (inode change, file modification or 897 both) are used in the comparison. 898 If neither is specified, the default is to use file modification time only. 899 The 900 .Ar m 901 specifies the comparison of file modification time (the time when 902 the file was last written). 903 The 904 .Ar c 905 specifies the comparison of inode change time (the time when the file 906 inode was last changed; e.g.\& a change of owner, group, mode, etc). 907 When 908 .Ar c 909 and 910 .Ar m 911 are both specified, then the modification and inode change times are 912 both compared. 913 The inode change time comparison is useful in selecting files whose 914 attributes were recently changed or selecting files which were recently 915 created and had their modification time reset to an older time (as what 916 happens when a file is extracted from an archive and the modification time 917 is preserved). 918 Time comparisons using both file times is useful when 919 .Nm 920 is used to create a time based incremental archive (only files that were 921 changed during a specified time range will be archived). 922 .Pp 923 A time range is made up of six different fields and each field must contain two 924 digits. 925 The format is: 926 .Dl [yy[mm[dd[hh]]]]mm[.ss] 927 Where 928 .Cm yy 929 is the last two digits of the year, 930 the first 931 .Cm mm 932 is the month (from 01 to 12), 933 .Cm dd 934 is the day of the month (from 01 to 31), 935 .Cm hh 936 is the hour of the day (from 00 to 23), 937 the second 938 .Cm mm 939 is the minute (from 00 to 59), 940 and 941 .Cm ss 942 is the seconds (from 00 to 59). 943 The minute field 944 .Cm mm 945 is required, while the other fields are optional and must be added in the 946 following order: 947 .Dl Cm hh , dd , mm , yy . 948 The 949 .Cm ss 950 field may be added independently of the other fields. 951 Time ranges are relative to the current time, so 952 .Dl Fl T Ar 1234/cm 953 would select all files with a modification or inode change time 954 of 12:34 PM today or later. 955 Multiple 956 .Fl T 957 time range can be supplied and checking stops with the first match. 958 .It Fl U Ar user 959 Select a file based on its 960 .Ar user 961 name, or when starting with a 962 .Cm # , 963 a numeric uid. 964 A '\\' can be used to escape the 965 .Cm # . 966 Multiple 967 .Fl U 968 options may be supplied and checking stops with the first match. 969 .It Fl X 970 When traversing the file hierarchy specified by a pathname, 971 do not descend into directories that have a different device ID. 972 See the 973 .Li st_dev 974 field as described in 975 .Xr stat 2 976 for more information about device ID's. 977 .It Fl Y 978 This option is the same as the 979 .Fl D 980 option, except that the inode change time is checked using the 981 pathname created after all the file name modifications have completed. 982 .It Fl Z 983 This option is the same as the 984 .Fl u 985 option, except that the modification time is checked using the 986 pathname created after all the file name modifications have completed. 987 .El 988 .Pp 989 The options that operate on the names of files or archive members 990 .Fl ( c , 991 .Fl i , 992 .Fl n , 993 .Fl s , 994 .Fl u , 995 .Fl v , 996 .Fl D , 997 .Fl G , 998 .Fl T , 999 .Fl U , 1000 .Fl Y , 1001 and 1002 .Fl Z ) 1003 interact as follows. 1004 .Pp 1005 When extracting files during a 1006 .Em read 1007 operation, archive members are 1008 .Sq selected , 1009 based only on the user specified pattern operands as modified by the 1010 .Fl c , 1011 .Fl n , 1012 .Fl u , 1013 .Fl D , 1014 .Fl G , 1015 .Fl T , 1016 .Fl U 1017 options. 1018 Then any 1019 .Fl s 1020 and 1021 .Fl i 1022 options will modify in that order, the names of these selected files. 1023 Then the 1024 .Fl Y 1025 and 1026 .Fl Z 1027 options will be applied based on the final pathname. 1028 Finally the 1029 .Fl v 1030 option will write the names resulting from these modifications. 1031 .Pp 1032 When archiving files during a 1033 .Em write 1034 operation, or copying files during a 1035 .Em copy 1036 operation, archive members are 1037 .Sq selected , 1038 based only on the user specified pathnames as modified by the 1039 .Fl n , 1040 .Fl u , 1041 .Fl D , 1042 .Fl G , 1043 .Fl T , 1044 and 1045 .Fl U 1046 options (the 1047 .Fl D 1048 option only applies during a copy operation). 1049 Then any 1050 .Fl s 1051 and 1052 .Fl i 1053 options will modify in that order, the names of these selected files. 1054 Then during a 1055 .Em copy 1056 operation the 1057 .Fl Y 1058 and the 1059 .Fl Z 1060 options will be applied based on the final pathname. 1061 Finally the 1062 .Fl v 1063 option will write the names resulting from these modifications. 1064 .Pp 1065 When one or both of the 1066 .Fl u 1067 or 1068 .Fl D 1069 options are specified along with the 1070 .Fl n 1071 option, a file is not considered selected unless it is newer 1072 than the file to which it is compared. 1073 .Sh EXIT STATUS 1074 The 1075 .Nm 1076 utility will exit with one of the following values: 1077 .Bl -tag -width 2n 1078 .It 0 1079 All files were processed successfully. 1080 .It 1 1081 An error occurred. 1082 .El 1083 .Sh EXAMPLES 1084 The command: 1085 .Dl "pax -w -f /dev/sa0 ." 1086 copies the contents of the current directory to the device 1087 .Pa /dev/sa0 . 1088 .Pp 1089 The command: 1090 .Dl pax -v -f filename 1091 gives the verbose table of contents for an archive stored in 1092 .Pa filename . 1093 .Pp 1094 The following commands: 1095 .Dl mkdir /tmp/to 1096 .Dl cd /tmp/from 1097 .Dl pax -rw .\ /tmp/to 1098 will copy the entire 1099 .Pa /tmp/from 1100 directory hierarchy to 1101 .Pa /tmp/to . 1102 .Pp 1103 The command: 1104 .Dl pax -r -s ',^//*usr//*,,' -f a.pax 1105 reads the archive 1106 .Pa a.pax , 1107 with all files rooted in ``/usr'' into the archive extracted relative to the 1108 current directory. 1109 .Pp 1110 The command: 1111 .Dl pax -rw -i .\ dest_dir 1112 can be used to interactively select the files to copy from the current 1113 directory to 1114 .Pa dest_dir . 1115 .Pp 1116 The command: 1117 .Dl pax -r -pe -U root -G bin -f a.pax 1118 will extract all files from the archive 1119 .Pa a.pax 1120 which are owned by 1121 .Em root 1122 with group 1123 .Em bin 1124 and will preserve all file permissions. 1125 .Pp 1126 The command: 1127 .Dl pax -r -w -v -Y -Z home /backup 1128 will update (and list) only those files in the destination directory 1129 .Pa /backup 1130 which are older (less recent inode change or file modification times) than 1131 files with the same name found in the source file tree 1132 .Pa home . 1133 .Sh DIAGNOSTICS 1134 Whenever 1135 .Nm 1136 cannot create a file or a link when reading an archive or cannot 1137 find a file when writing an archive, or cannot preserve the user ID, 1138 group ID, or file mode when the 1139 .Fl p 1140 option is specified, a diagnostic message is written to 1141 .Dv standard error 1142 and a non-zero exit status will be returned, but processing will continue. 1143 In the case where pax cannot create a link to a file, 1144 .Nm 1145 will not create a second copy of the file. 1146 .Pp 1147 If the extraction of a file from an archive is prematurely terminated by 1148 a signal or error, 1149 .Nm 1150 may have only partially extracted a file the user wanted. 1151 Additionally, the file modes of extracted files and directories 1152 may have incorrect file bits, and the modification and access times may be 1153 wrong. 1154 .Pp 1155 If the creation of an archive is prematurely terminated by a signal or error, 1156 .Nm 1157 may have only partially created the archive which may violate the specific 1158 archive format specification. 1159 .Pp 1160 If while doing a 1161 .Em copy , 1162 .Nm 1163 detects a file is about to overwrite itself, the file is not copied, 1164 a diagnostic message is written to 1165 .Dv standard error 1166 and when 1167 .Nm 1168 completes it will exit with a non-zero exit status. 1169 .Sh SEE ALSO 1170 .Xr cpio 1 , 1171 .Xr tar 1 1172 .Sh STANDARDS 1173 The 1174 .Nm 1175 utility is a superset of the 1176 .St -p1003.2 1177 standard. 1178 The options 1179 .Fl z , 1180 .Fl B , 1181 .Fl D , 1182 .Fl E , 1183 .Fl G , 1184 .Fl H , 1185 .Fl L , 1186 .Fl O , 1187 .Fl P , 1188 .Fl T , 1189 .Fl U , 1190 .Fl Y , 1191 .Fl Z , 1192 the archive formats 1193 .Ar bcpio , 1194 .Ar sv4cpio , 1195 .Ar sv4crc , 1196 .Ar tar , 1197 and the flawed archive handling during 1198 .Ar list 1199 and 1200 .Ar read 1201 operations are extensions to the 1202 .Tn POSIX 1203 standard. 1204 .Sh HISTORY 1205 The 1206 .Nm 1207 utility appeared in 1208 .Bx 4.4 . 1209 .Sh AUTHORS 1210 .An Keith Muller 1211 at the University of California, San Diego 1212 .Sh BUGS 1213 The 1214 .Nm 1215 utility does not recognize multibyte characters. 1216 .Pp 1217 File flags set by 1218 .Xr chflags 1 1219 are not preserved by 1220 .Nm . 1221 The BUGS section of 1222 .Xr chflags 1 1223 has a list of utilities that are unaware of flags. 1224