2 * Copyright (c) 1992 Keith Muller.
3 * Copyright (c) 1992, 1993
4 * The Regents of the University of California. All rights reserved.
6 * This code is derived from software contributed to Berkeley by
7 * Keith Muller of the University of California, San Diego.
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
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 * 3. 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.
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
33 * @(#)ar_subs.c 8.2 (Berkeley) 4/18/94
34 * $FreeBSD: src/bin/pax/ar_subs.c,v 1.13.2.1 2001/08/01 05:03:11 obrien Exp $
35 * $DragonFly: src/bin/pax/ar_subs.c,v 1.7 2006/09/27 21:58:08 pavalos Exp $
38 #include <sys/types.h>
51 static void wr_archive (ARCHD *, int is_app);
52 static int get_arc (void);
53 static int next_head (ARCHD *);
54 extern sigset_t s_mask;
57 * Routines which control the overall operation modes of pax as specified by
58 * the user: list, append, read ...
61 static char hdbuf[BLKMULT]; /* space for archive header on read */
62 u_long flcnt; /* number of files processed */
66 * list the contents of an archive which match user supplied pattern(s)
67 * (no pattern matches all).
80 * figure out archive type; pass any format specific options to the
81 * archive option processing routine; call the format init routine. We
82 * also save current time for ls_list() so we do not make a system
83 * call for each file we need to print. If verbose (vflag) start up
84 * the name and group caches.
86 if ((get_arc() < 0) || ((*frmt->options)() < 0) ||
87 ((*frmt->st_rd)() < 0))
90 if (vflag && ((uidtb_start() < 0) || (gidtb_start() < 0)))
96 * step through the archive until the format says it is done
98 while (next_head(arcn) == 0) {
100 * check for pattern, and user specified options match.
101 * When all patterns are matched we are done.
103 if ((res = pat_match(arcn)) < 0)
106 if ((res == 0) && (sel_chk(arcn) == 0)) {
108 * pattern resulted in a selected file
110 if (pat_sel(arcn) < 0)
114 * modify the name as requested by the user if name
115 * survives modification, do a listing of the file
117 if ((res = mod_name(arcn)) < 0)
120 ls_list(arcn, now, stdout);
124 * skip to next archive format header using values calculated
125 * by the format header read routine
127 if (rd_skip(arcn->skip + arcn->pad) == 1)
132 * all done, let format have a chance to cleanup, and make sure that
133 * the patterns supplied by the user were all matched
136 sigprocmask(SIG_BLOCK, &s_mask, NULL);
143 * extract the member(s) of an archive as specified by user supplied
144 * pattern(s) (no patterns extracts all members)
160 * figure out archive type; pass any format specific options to the
161 * archive option processing routine; call the format init routine;
162 * start up the directory modification time and access mode database
164 if ((get_arc() < 0) || ((*frmt->options)() < 0) ||
165 ((*frmt->st_rd)() < 0) || (dir_start() < 0))
169 * When we are doing interactive rename, we store the mapping of names
170 * so we can fix up hard links files later in the archive.
172 if (iflag && (name_start() < 0))
178 * step through each entry on the archive until the format read routine
181 while (next_head(arcn) == 0) {
184 * check for pattern, and user specified options match. When
185 * all the patterns are matched we are done
187 if ((res = pat_match(arcn)) < 0)
190 if ((res > 0) || (sel_chk(arcn) != 0)) {
192 * file is not selected. skip past any file data and
193 * padding and go back for the next archive member
195 rd_skip(arcn->skip + arcn->pad);
200 * with -u or -D only extract when the archive member is newer
201 * than the file with the same name in the file system (no
202 * test of being the same type is required).
203 * NOTE: this test is done BEFORE name modifications as
204 * specified by pax. this operation can be confusing to the
205 * user who might expect the test to be done on an existing
206 * file AFTER the name mod. In honesty the pax spec is probably
207 * flawed in this respect.
209 if ((uflag || Dflag) && ((lstat(arcn->name, &sb) == 0))) {
210 if (uflag && Dflag) {
211 if ((arcn->sb.st_mtime <= sb.st_mtime) &&
212 (arcn->sb.st_ctime <= sb.st_ctime)) {
213 rd_skip(arcn->skip + arcn->pad);
217 if (arcn->sb.st_ctime <= sb.st_ctime) {
218 rd_skip(arcn->skip + arcn->pad);
221 } else if (arcn->sb.st_mtime <= sb.st_mtime) {
222 rd_skip(arcn->skip + arcn->pad);
228 * this archive member is now been selected. modify the name.
230 if ((pat_sel(arcn) < 0) || ((res = mod_name(arcn)) < 0))
234 * a bad name mod, skip and purge name from link table
237 rd_skip(arcn->skip + arcn->pad);
242 * Non standard -Y and -Z flag. When the existing file is
243 * same age or newer skip
245 if ((Yflag || Zflag) && ((lstat(arcn->name, &sb) == 0))) {
246 if (Yflag && Zflag) {
247 if ((arcn->sb.st_mtime <= sb.st_mtime) &&
248 (arcn->sb.st_ctime <= sb.st_ctime)) {
249 rd_skip(arcn->skip + arcn->pad);
253 if (arcn->sb.st_ctime <= sb.st_ctime) {
254 rd_skip(arcn->skip + arcn->pad);
257 } else if (arcn->sb.st_mtime <= sb.st_mtime) {
258 rd_skip(arcn->skip + arcn->pad);
265 ls_list(arcn, now, listf);
267 fputs(arcn->name, listf);
273 * if required, chdir around.
275 if ((arcn->pat != NULL) && (arcn->pat->chdname != NULL))
276 if (chdir(arcn->pat->chdname) != 0)
277 syswarn(1, errno, "Cannot chdir to %s",
281 * all ok, extract this member based on type
283 if ((arcn->type != PAX_REG) && (arcn->type != PAX_CTG)) {
285 * process archive members that are not regular files.
286 * throw out padding and any data that might follow the
287 * header (as determined by the format).
289 if ((arcn->type == PAX_HLK) || (arcn->type == PAX_HRG))
290 res = lnk_creat(arcn);
292 res = node_creat(arcn);
294 rd_skip(arcn->skip + arcn->pad);
298 if (vflag && vfpart) {
305 * we have a file with data here. If we can not create it, skip
306 * over the data and purge the name from hard link table
308 if ((fd = file_creat(arcn)) < 0) {
309 rd_skip(arcn->skip + arcn->pad);
314 * extract the file from the archive and skip over padding and
315 * any unprocessed data
317 res = (*frmt->rd_data)(arcn, fd, &cnt);
318 file_close(arcn, fd);
319 if (vflag && vfpart) {
324 rd_skip(cnt + arcn->pad);
327 * if required, chdir around.
329 if ((arcn->pat != NULL) && (arcn->pat->chdname != NULL))
330 if (fchdir(cwdfd) != 0)
332 "Can't fchdir to starting directory");
336 * all done, restore directory modes and times as required; make sure
337 * all patterns supplied by the user were matched; block off signals
338 * to avoid chance for multiple entry into the cleanup code.
341 sigprocmask(SIG_BLOCK, &s_mask, NULL);
349 * Write an archive. used in both creating a new archive and appends on
350 * previously written archive.
354 wr_archive(ARCHD *arcn, int is_app)
365 * if this format supports hard link storage, start up the database
368 if (((hlk = frmt->hlk) == 1) && (lnk_start() < 0))
372 * start up the file traversal code and format specific write
374 if ((ftree_start() < 0) || ((*frmt->st_wr)() < 0))
379 * When we are doing interactive rename, we store the mapping of names
380 * so we can fix up hard links files later in the archive.
382 if (iflag && (name_start() < 0))
386 * if this not append, and there are no files, we do no write a trailer
393 * while there are files to archive, process them one at at time
395 while (next_file(arcn) == 0) {
397 * check if this file meets user specified options match.
399 if (sel_chk(arcn) != 0)
404 * only archive if this file is newer than a file with
405 * the same name that is already stored on the archive
407 if ((res = chk_ftime(arcn)) < 0)
414 * this file is considered selected now. see if this is a hard
415 * link to a file already stored
418 if (hlk && (chk_lnk(arcn) < 0))
421 if ((arcn->type == PAX_REG) || (arcn->type == PAX_HRG) ||
422 (arcn->type == PAX_CTG)) {
424 * we will have to read this file. by opening it now we
425 * can avoid writing a header to the archive for a file
426 * we were later unable to read (we also purge it from
429 if ((fd = open(arcn->org_name, O_RDONLY, 0)) < 0) {
430 syswarn(1,errno, "Unable to open %s to read",
438 * Now modify the name as requested by the user
440 if ((res = mod_name(arcn)) < 0) {
442 * name modification says to skip this file, close the
443 * file and purge link table entry
445 rdfile_close(arcn, &fd);
450 if ((res > 0) || (docrc && (set_crc(arcn, fd) < 0))) {
452 * unable to obtain the crc we need, close the file,
453 * purge link table entry
455 rdfile_close(arcn, &fd);
462 ls_list(arcn, now, listf);
464 fputs(arcn->name, listf);
471 * looks safe to store the file, have the format specific
472 * routine write routine store the file header on the archive
474 if ((res = (*wrf)(arcn)) < 0) {
475 rdfile_close(arcn, &fd);
481 * format write says no file data needs to be stored
482 * so we are done messing with this file
484 if (vflag && vfpart) {
488 rdfile_close(arcn, &fd);
493 * Add file data to the archive, quit on write error. if we
494 * cannot write the entire file contents to the archive we
495 * must pad the archive to replace the missing file data
496 * (otherwise during an extract the file header for the file
497 * which FOLLOWS this one will not be where we expect it to
500 res = (*frmt->wr_data)(arcn, fd, &cnt);
501 rdfile_close(arcn, &fd);
502 if (vflag && vfpart) {
510 * pad as required, cnt is number of bytes not written
512 if (((cnt > 0) && (wr_skip(cnt) < 0)) ||
513 ((arcn->pad > 0) && (wr_skip(arcn->pad) < 0)))
518 * tell format to write trailer; pad to block boundary; reset directory
519 * mode/access times, and check if all patterns supplied by the user
520 * were matched. block off signals to avoid chance for multiple entry
521 * into the cleanup code
527 sigprocmask(SIG_BLOCK, &s_mask, NULL);
536 * Add file to previously written archive. Archive format specified by the
537 * user must agree with archive. The archive is read first to collect
538 * modification times (if -u) and locate the archive trailer. The archive
539 * is positioned in front of the record with the trailer and wr_archive()
540 * is called to add the new members.
541 * PAX IMPLEMENTATION DETAIL NOTE:
542 * -u is implemented by adding the new members to the end of the archive.
543 * Care is taken so that these do not end up as links to the older
544 * version of the same file already stored in the archive. It is expected
545 * when extraction occurs these newer versions will over-write the older
546 * ones stored "earlier" in the archive (this may be a bad assumption as
547 * it depends on the implementation of the program doing the extraction).
548 * It is really difficult to splice in members without either re-writing
549 * the entire archive (from the point were the old version was), or having
550 * assistance of the format specification in terms of a special update
551 * header that invalidates a previous archive record. The POSIX spec left
552 * the method used to implement -u unspecified. This pax is able to
553 * over write existing files that it creates.
570 * Do not allow an append operation if the actual archive is of a
571 * different format than the user specified format.
575 if ((orgfrmt != NULL) && (orgfrmt != frmt)) {
576 paxwarn(1, "Cannot mix current archive format %s with %s",
577 frmt->name, orgfrmt->name);
582 * pass the format any options and start up format
584 if (((*frmt->options)() < 0) || ((*frmt->st_rd)() < 0))
588 * if we only are adding members that are newer, we need to save the
589 * mod times for all files we see.
591 if (uflag && (ftime_start() < 0))
595 * some archive formats encode hard links by recording the device and
596 * file serial number (inode) but copy the file anyway (multiple times)
597 * to the archive. When we append, we run the risk that newly added
598 * files may have the same device and inode numbers as those recorded
599 * on the archive but during a previous run. If this happens, when the
600 * archive is extracted we get INCORRECT hard links. We avoid this by
601 * remapping the device numbers so that newly added files will never
602 * use the same device number as one found on the archive. remapping
603 * allows new members to safely have links among themselves. remapping
604 * also avoids problems with file inode (serial number) truncations
605 * when the inode number is larger than storage space in the archive
606 * header. See the remap routines for more details.
608 if ((udev = frmt->udev) && (dev_start() < 0))
612 * reading the archive may take a long time. If verbose tell the user
616 "%s: Reading archive to position at the end...", argv0);
621 * step through the archive until the format says it is done
623 while (next_head(arcn) == 0) {
625 * check if this file meets user specified options.
627 if (sel_chk(arcn) != 0) {
628 if (rd_skip(arcn->skip + arcn->pad) == 1)
635 * see if this is the newest version of this file has
636 * already been seen, if so skip.
638 if ((res = chk_ftime(arcn)) < 0)
641 if (rd_skip(arcn->skip + arcn->pad) == 1)
648 * Store this device number. Device numbers seen during the
649 * read phase of append will cause newly appended files with a
650 * device number seen in the old part of the archive to be
651 * remapped to an unused device number.
653 if ((udev && (add_dev(arcn) < 0)) ||
654 (rd_skip(arcn->skip + arcn->pad) == 1))
659 * done, finish up read and get the number of bytes to back up so we
660 * can add new members. The format might have used the hard link table,
663 tlen = (*frmt->end_rd)();
667 * try to position for write, if this fails quit. if any error occurs,
668 * we will refuse to write
670 if (appnd_start(tlen) < 0)
674 * tell the user we are done reading.
676 if (vflag && vfpart) {
677 fputs("done.\n", listf);
682 * go to the writing phase to add the new members
689 * write a new archive
698 * if we only are adding members that are newer, we need to save the
699 * mod times for all files; set up for writing; pass the format any
700 * options write the archive
702 if ((uflag && (ftime_start() < 0)) || (wr_start() < 0))
704 if ((*frmt->options)() < 0)
707 wr_archive(&archd, 0);
712 * copy files from one part of the file system to another. this does not
713 * use any archive storage. The EFFECT OF THE COPY IS THE SAME as if an
714 * archive was written and then extracted in the destination directory
715 * (except the files are forced to be under the destination directory).
730 char dirbuf[PAXPATHLEN+1];
734 * set up the destination dir path and make sure it is a directory. We
735 * make sure we have a trailing / on the destination
737 dlen = l_strncpy(dirbuf, dirptr, sizeof(dirbuf) - 1);
738 dest_pt = dirbuf + dlen;
739 if (*(dest_pt-1) != '/') {
744 drem = PAXPATHLEN - dlen;
746 if (stat(dirptr, &sb) < 0) {
747 syswarn(1, errno, "Cannot access destination directory %s",
751 if (!S_ISDIR(sb.st_mode)) {
752 paxwarn(1, "Destination is not a directory %s", dirptr);
757 * start up the hard link table; file traversal routines and the
758 * modification time and access mode database
760 if ((lnk_start() < 0) || (ftree_start() < 0) || (dir_start() < 0))
764 * When we are doing interactive rename, we store the mapping of names
765 * so we can fix up hard links files later in the archive.
767 if (iflag && (name_start() < 0))
771 * set up to cp file trees
776 * while there are files to archive, process them
778 while (next_file(arcn) == 0) {
782 * check if this file meets user specified options
784 if (sel_chk(arcn) != 0)
788 * if there is already a file in the destination directory with
789 * the same name and it is newer, skip the one stored on the
791 * NOTE: this test is done BEFORE name modifications as
792 * specified by pax. this can be confusing to the user who
793 * might expect the test to be done on an existing file AFTER
794 * the name mod. In honesty the pax spec is probably flawed in
797 if (uflag || Dflag) {
799 * create the destination name
801 if (*(arcn->name) == '/')
805 if ((arcn->nlen - res) > drem) {
806 paxwarn(1, "Destination pathname too long %s",
810 strncpy(dest_pt, arcn->name + res, drem);
811 dirbuf[PAXPATHLEN] = '\0';
814 * if existing file is same age or newer skip
816 res = lstat(dirbuf, &sb);
820 if (uflag && Dflag) {
821 if ((arcn->sb.st_mtime<=sb.st_mtime) &&
822 (arcn->sb.st_ctime<=sb.st_ctime))
825 if (arcn->sb.st_ctime <= sb.st_ctime)
827 } else if (arcn->sb.st_mtime <= sb.st_mtime)
833 * this file is considered selected. See if this is a hard link
834 * to a previous file; modify the name as requested by the
835 * user; set the final destination.
838 if ((chk_lnk(arcn) < 0) || ((res = mod_name(arcn)) < 0))
840 if ((res > 0) || (set_dest(arcn, dirbuf, dlen) < 0)) {
842 * skip file, purge from link table
849 * Non standard -Y and -Z flag. When the existing file is
850 * same age or newer skip
852 if ((Yflag || Zflag) && ((lstat(arcn->name, &sb) == 0))) {
853 if (Yflag && Zflag) {
854 if ((arcn->sb.st_mtime <= sb.st_mtime) &&
855 (arcn->sb.st_ctime <= sb.st_ctime))
858 if (arcn->sb.st_ctime <= sb.st_ctime)
860 } else if (arcn->sb.st_mtime <= sb.st_mtime)
865 fputs(arcn->name, listf);
871 * try to create a hard link to the src file if requested
872 * but make sure we are not trying to overwrite ourselves.
875 res = cross_lnk(arcn);
877 res = chk_same(arcn);
879 if (vflag && vfpart) {
887 * have to create a new file
889 if ((arcn->type != PAX_REG) && (arcn->type != PAX_CTG)) {
891 * create a link or special file
893 if ((arcn->type == PAX_HLK) || (arcn->type == PAX_HRG))
894 res = lnk_creat(arcn);
896 res = node_creat(arcn);
899 if (vflag && vfpart) {
907 * have to copy a regular file to the destination directory.
908 * first open source file and then create the destination file
910 if ((fdsrc = open(arcn->org_name, O_RDONLY, 0)) < 0) {
911 syswarn(1, errno, "Unable to open %s to read",
916 if ((fddest = file_creat(arcn)) < 0) {
917 rdfile_close(arcn, &fdsrc);
923 * copy source file data to the destination file
925 cp_file(arcn, fdsrc, fddest);
926 file_close(arcn, fddest);
927 rdfile_close(arcn, &fdsrc);
929 if (vflag && vfpart) {
936 * restore directory modes and times as required; make sure all
937 * patterns were selected block off signals to avoid chance for
938 * multiple entry into the cleanup code.
940 sigprocmask(SIG_BLOCK, &s_mask, NULL);
948 * try to find a valid header in the archive. Uses format specific
949 * routines to extract the header and id the trailer. Trailers may be
950 * located within a valid header or in an invalid header (the location
951 * is format specific. The inhead field from the option table tells us
952 * where to look for the trailer).
953 * We keep reading (and resyncing) until we get enough contiguous data
954 * to check for a header. If we cannot find one, we shift by a byte
955 * add a new byte from the archive to the end of the buffer and try again.
956 * If we get a read error, we throw out what we have (as we must have
957 * contiguous data) and start over again.
958 * ASSUMED: headers fit within a BLKMULT header.
960 * 0 if we got a header, -1 if we are unable to ever find another one
961 * (we reached the end of input, or we reached the limit on retries. see
962 * the specs for rd_wrbuf() for more details)
966 next_head(ARCHD *arcn)
973 int in_resync = 0; /* set when we are in resync mode */
974 int cnt = 0; /* counter for trailer function */
975 int first = 1; /* on 1st read, EOF isn't premature. */
978 * set up initial conditions, we want a whole frmt->hsz block as we
981 res = hsz = frmt->hsz;
986 * keep looping until we get a contiguous FULL buffer
987 * (frmt->hsz is the proper size)
990 if ((ret = rd_wrbuf(hdend, res)) == res)
994 * If we read 0 bytes (EOF) from an archive when we
995 * expect to find a header, we have stepped upon
996 * an archive without the customary block of zeroes
997 * end marker. It's just stupid to error out on
998 * them, so exit gracefully.
1000 if (first && ret == 0)
1005 * some kind of archive read problem, try to resync the
1006 * storage device, better give the user the bad news.
1008 if ((ret == 0) || (rd_sync() < 0)) {
1009 paxwarn(1,"Premature end of file on archive read");
1015 "Archive I/O error, cannot continue");
1018 paxwarn(1,"Archive I/O error. Trying to recover.");
1023 * oh well, throw it all out and start over
1030 * ok we have a contiguous buffer of the right size. Call the
1031 * format read routine. If this was not a valid header and this
1032 * format stores trailers outside of the header, call the
1033 * format specific trailer routine to check for a trailer. We
1034 * have to watch out that we do not mis-identify file data or
1035 * block padding as a header or trailer. Format specific
1036 * trailer functions must NOT check for the trailer while we
1037 * are running in resync mode. Some trailer functions may tell
1038 * us that this block cannot contain a valid header either, so
1039 * we then throw out the entire block and start over.
1041 if ((*frmt->rd)(arcn, hdbuf) == 0)
1044 if (!frmt->inhead) {
1046 * this format has trailers outside of valid headers
1048 if ((ret = (*frmt->trail)(hdbuf,in_resync,&cnt)) == 0){
1050 * valid trailer found, drain input as required
1058 * we are in resync and we were told to throw
1059 * the whole block out because none of the
1060 * bytes in this block can be used to form a
1070 * Brute force section.
1071 * not a valid header. We may be able to find a header yet. So
1072 * we shift over by one byte, and set up to read one byte at a
1073 * time from the archive and place it at the end of the buffer.
1074 * We will keep moving byte at a time until we find a header or
1075 * get a read error and have to start over.
1079 paxwarn(1,"Unable to append, archive header flaw");
1082 paxwarn(1,"Invalid header, starting valid header search.");
1085 memmove(hdbuf, hdbuf+1, shftsz);
1087 hdend = hdbuf + shftsz;
1091 * ok got a valid header, check for trailer if format encodes it in the
1092 * the header. NOTE: the parameters are different than trailer routines
1093 * which encode trailers outside of the header!
1095 if (frmt->inhead && ((*frmt->trail)(arcn) == 0)) {
1097 * valid trailer found, drain input as required
1109 * Figure out what format an archive is. Handles archive with flaws by
1110 * brute force searches for a legal header in any supported format. The
1111 * format id routines have to be careful to NOT mis-identify a format.
1112 * ASSUMED: headers fit within a BLKMULT header.
1114 * 0 if archive found -1 otherwise
1123 int minhd = BLKMULT;
1128 * find the smallest header size in all archive formats and then set up
1129 * to read the archive.
1131 for (i = 0; ford[i] >= 0; ++i) {
1132 if (fsub[ford[i]].hsz < minhd)
1133 minhd = fsub[ford[i]].hsz;
1143 * fill the buffer with at least the smallest header
1145 i = rd_wrbuf(hdend, res);
1152 * if we cannot recover from a read error quit
1154 if ((i == 0) || (rd_sync() < 0))
1158 * when we get an error none of the data we already
1159 * have can be used to create a legal header (we just
1160 * got an error in the middle), so we throw it all out
1161 * and refill the buffer with fresh data.
1169 paxwarn(1,"Cannot identify format. Searching...");
1175 * we have at least the size of the smallest header in any
1176 * archive format. Look to see if we have a match. The array
1177 * ford[] is used to specify the header id order to reduce the
1178 * chance of incorrectly id'ing a valid header (some formats
1179 * may be subsets of each other and the order would then be
1182 for (i = 0; ford[i] >= 0; ++i) {
1183 if ((*fsub[ford[i]].id)(hdbuf, hdsz) < 0)
1185 frmt = &(fsub[ford[i]]);
1187 * yuck, to avoid slow special case code in the extract
1188 * routines, just push this header back as if it was
1189 * not seen. We have left extra space at start of the
1190 * buffer for this purpose. This is a bit ugly, but
1191 * adding all the special case code is far worse.
1198 * We have a flawed archive, no match. we start searching, but
1199 * we never allow additions to flawed archives
1204 paxwarn(1, "Cannot identify format. Searching...");
1209 * brute force search for a header that we can id.
1210 * we shift through byte at a time. this is slow, but we cannot
1211 * determine the nature of the flaw in the archive in a
1215 memmove(hdbuf, hdbuf+1, hdsz);
1216 res = BLKMULT - hdsz;
1217 hdend = hdbuf + hdsz;
1227 * we cannot find a header, bow, apologize and quit
1229 paxwarn(1, "Sorry, unable to determine archive format.");