Dogcows Code - chaz/tar/blob - src/system.c

   1 /* System-dependent calls for tar.
   2
   3    Copyright (C) 2003, 2004, 2005, 2006, 2007,
   4    2008 Free Software Foundation, Inc.
   5
   6    This program is free software; you can redistribute it and/or modify it
   7    under the terms of the GNU General Public License as published by the
   8    Free Software Foundation; either version 3, or (at your option) any later
   9    version.
  10
  11    This program is distributed in the hope that it will be useful, but
  12    WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
  14    Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License along
  17    with this program; if not, write to the Free Software Foundation, Inc.,
  18    51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  19
  20 #include <system.h>
  21
  22 #include "common.h"
  23 #include <rmt.h>
  24 #include <signal.h>
  25
  26 #if MSDOS
  27
  28 bool
  29 sys_get_archive_stat (void)
  30 {
  31   return 0;
  32 }
  33
  34 bool
  35 sys_file_is_archive (struct tar_stat_info *p)
  36 {
  37   return false;
  38 }
  39
  40 void
  41 sys_save_archive_dev_ino (void)
  42 {
  43 }
  44
  45 void
  46 sys_detect_dev_null_output (void)
  47 {
  48   static char const dev_null[] = "nul";
  49
  50   dev_null_output = (strcmp (archive_name_array[0], dev_null) == 0
  51                      || (! _isrmt (archive)));
  52 }
  53
  54 void
  55 sys_wait_for_child (pid_t child_pid, bool eof)
  56 {
  57 }
  58
  59 void
  60 sys_spawn_shell (void)
  61 {
  62   spawnl (P_WAIT, getenv ("COMSPEC"), "-", 0);
  63 }
  64
  65 /* stat() in djgpp's C library gives a constant number of 42 as the
  66    uid and gid of a file.  So, comparing an FTP'ed archive just after
  67    unpack would fail on MSDOS.  */
  68
  69 bool
  70 sys_compare_uid (struct stat *a, struct stat *b)
  71 {
  72   return true;
  73 }
  74
  75 bool
  76 sys_compare_gid (struct stat *a, struct stat *b)
  77 {
  78   return true;
  79 }
  80
  81 void
  82 sys_compare_links (struct stat *link_data, struct stat *stat_data)
  83 {
  84   return true;
  85 }
  86
  87 int
  88 sys_truncate (int fd)
  89 {
  90   return write (fd, "", 0);
  91 }
  92
  93 size_t
  94 sys_write_archive_buffer (void)
  95 {
  96   return full_write (archive, record_start->buffer, record_size);
  97 }
  98
  99 /* Set ARCHIVE for writing, then compressing an archive.  */
 100 void
 101 sys_child_open_for_compress (void)
 102 {
 103   FATAL_ERROR ((0, 0, _("Cannot use compressed or remote archives")));
 104 }
 105
 106 /* Set ARCHIVE for uncompressing, then reading an archive.  */
 107 void
 108 sys_child_open_for_uncompress (void)
 109 {
 110   FATAL_ERROR ((0, 0, _("Cannot use compressed or remote archives")));
 111 }
 112
 113 #else
 114
 115 extern union block *record_start; /* FIXME */
 116
 117 static struct stat archive_stat; /* stat block for archive file */
 118
 119 bool
 120 sys_get_archive_stat (void)
 121 {
 122   return fstat (archive, &archive_stat) == 0;
 123 }
 124
 125 bool
 126 sys_file_is_archive (struct tar_stat_info *p)
 127 {
 128   return (ar_dev && p->stat.st_dev == ar_dev && p->stat.st_ino == ar_ino);
 129 }
 130
 131 /* Save archive file inode and device numbers */
 132 void
 133 sys_save_archive_dev_ino (void)
 134 {
 135   if (!_isrmt (archive) && S_ISREG (archive_stat.st_mode))
 136     {
 137       ar_dev = archive_stat.st_dev;
 138       ar_ino = archive_stat.st_ino;
 139     }
 140   else
 141     ar_dev = 0;
 142 }
 143
 144 /* Detect if outputting to "/dev/null".  */
 145 void
 146 sys_detect_dev_null_output (void)
 147 {
 148   static char const dev_null[] = "/dev/null";
 149   struct stat dev_null_stat;
 150
 151   dev_null_output = (strcmp (archive_name_array[0], dev_null) == 0
 152                      || (! _isrmt (archive)
 153                          && S_ISCHR (archive_stat.st_mode)
 154                          && stat (dev_null, &dev_null_stat) == 0
 155                          && archive_stat.st_dev == dev_null_stat.st_dev
 156                          && archive_stat.st_ino == dev_null_stat.st_ino));
 157 }
 158
 159 void
 160 sys_wait_for_child (pid_t child_pid, bool eof)
 161 {
 162   if (child_pid)
 163     {
 164       int wait_status;
 165
 166       while (waitpid (child_pid, &wait_status, 0) == -1)
 167         if (errno != EINTR)
 168           {
 169             waitpid_error (use_compress_program_option);
 170             break;
 171           }
 172
 173       if (WIFSIGNALED (wait_status))
 174         {
 175           int sig = WTERMSIG (wait_status);
 176           if (!(!eof && sig == SIGPIPE))
 177             FATAL_ERROR ((0, 0, _("Child died with signal %d"), sig));
 178         }
 179       else if (WEXITSTATUS (wait_status) != 0)
 180         FATAL_ERROR ((0, 0, _("Child returned status %d"),
 181                       WEXITSTATUS (wait_status)));
 182     }
 183 }
 184
 185 void
 186 sys_spawn_shell (void)
 187 {
 188   pid_t child;
 189   const char *shell = getenv ("SHELL");
 190   if (! shell)
 191     shell = "/bin/sh";
 192   child = xfork ();
 193   if (child == 0)
 194     {
 195       execlp (shell, "-sh", "-i", (char *) 0);
 196       exec_fatal (shell);
 197     }
 198   else
 199     {
 200       int wait_status;
 201       while (waitpid (child, &wait_status, 0) == -1)
 202         if (errno != EINTR)
 203           {
 204             waitpid_error (shell);
 205             break;
 206           }
 207     }
 208 }
 209
 210 bool
 211 sys_compare_uid (struct stat *a, struct stat *b)
 212 {
 213   return a->st_uid == b->st_uid;
 214 }
 215
 216 bool
 217 sys_compare_gid (struct stat *a, struct stat *b)
 218 {
 219   return a->st_gid == b->st_gid;
 220 }
 221
 222 bool
 223 sys_compare_links (struct stat *link_data, struct stat *stat_data)
 224 {
 225   return stat_data->st_dev == link_data->st_dev
 226          && stat_data->st_ino == link_data->st_ino;
 227 }
 228
 229 int
 230 sys_truncate (int fd)
 231 {
 232   off_t pos = lseek (fd, (off_t) 0, SEEK_CUR);
 233   return pos < 0 ? -1 : ftruncate (fd, pos);
 234 }
 235
 236 /* Return nonzero if NAME is the name of a regular file, or if the file
 237    does not exist (so it would be created as a regular file).  */
 238 static int
 239 is_regular_file (const char *name)
 240 {
 241   struct stat stbuf;
 242
 243   if (stat (name, &stbuf) == 0)
 244     return S_ISREG (stbuf.st_mode);
 245   else
 246     return errno == ENOENT;
 247 }
 248
 249 size_t
 250 sys_write_archive_buffer (void)
 251 {
 252   return rmtwrite (archive, record_start->buffer, record_size);
 253 }
 254
 255 #define PREAD 0                 /* read file descriptor from pipe() */
 256 #define PWRITE 1                /* write file descriptor from pipe() */
 257
 258 /* Duplicate file descriptor FROM into becoming INTO.
 259    INTO is closed first and has to be the next available slot.  */
 260 static void
 261 xdup2 (int from, int into)
 262 {
 263   if (from != into)
 264     {
 265       int status = close (into);
 266
 267       if (status != 0 && errno != EBADF)
 268         {
 269           int e = errno;
 270           FATAL_ERROR ((0, e, _("Cannot close")));
 271         }
 272       status = dup (from);
 273       if (status != into)
 274         {
 275           if (status < 0)
 276             {
 277               int e = errno;
 278               FATAL_ERROR ((0, e, _("Cannot dup")));
 279             }
 280           abort ();
 281         }
 282       xclose (from);
 283     }
 284 }
 285
 286 void wait_for_grandchild (pid_t pid) __attribute__ ((__noreturn__));
 287
 288 /* Propagate any failure of the grandchild back to the parent.  */
 289 void
 290 wait_for_grandchild (pid_t pid)
 291 {
 292   int wait_status;
 293   int exit_code = 0;
 294
 295   while (waitpid (pid, &wait_status, 0) == -1)
 296     if (errno != EINTR)
 297       {
 298         waitpid_error (use_compress_program_option);
 299         break;
 300       }
 301
 302   if (WIFSIGNALED (wait_status))
 303     raise (WTERMSIG (wait_status));
 304   else if (WEXITSTATUS (wait_status) != 0)
 305     exit_code = WEXITSTATUS (wait_status);
 306
 307   exit (exit_code);
 308 }
 309
 310 /* Set ARCHIVE for writing, then compressing an archive.  */
 311 pid_t
 312 sys_child_open_for_compress (void)
 313 {
 314   int parent_pipe[2];
 315   int child_pipe[2];
 316   pid_t grandchild_pid;
 317   pid_t child_pid;
 318
 319   xpipe (parent_pipe);
 320   child_pid = xfork ();
 321
 322   if (child_pid > 0)
 323     {
 324       /* The parent tar is still here!  Just clean up.  */
 325
 326       archive = parent_pipe[PWRITE];
 327       xclose (parent_pipe[PREAD]);
 328       return child_pid;
 329     }
 330
 331   /* The new born child tar is here!  */
 332
 333   set_program_name (_("tar (child)"));
 334   signal (SIGPIPE, SIG_DFL);
 335
 336   xdup2 (parent_pipe[PREAD], STDIN_FILENO);
 337   xclose (parent_pipe[PWRITE]);
 338
 339   /* Check if we need a grandchild tar.  This happens only if either:
 340      a) the file is to be accessed by rmt: compressor doesn't know how;
 341      b) the file is not a plain file.  */
 342
 343   if (!_remdev (archive_name_array[0])
 344       && is_regular_file (archive_name_array[0]))
 345     {
 346       if (backup_option)
 347         maybe_backup_file (archive_name_array[0], 1);
 348
 349       /* We don't need a grandchild tar.  Open the archive and launch the
 350          compressor.  */
 351       if (strcmp (archive_name_array[0], "-"))
 352         {
 353           archive = creat (archive_name_array[0], MODE_RW);
 354           if (archive < 0)
 355             {
 356               int saved_errno = errno;
 357
 358               if (backup_option)
 359                 undo_last_backup ();
 360               errno = saved_errno;
 361               open_fatal (archive_name_array[0]);
 362             }
 363           xdup2 (archive, STDOUT_FILENO);
 364         }
 365       execlp (use_compress_program_option, use_compress_program_option, NULL);
 366       exec_fatal (use_compress_program_option);
 367     }
 368
 369   /* We do need a grandchild tar.  */
 370
 371   xpipe (child_pipe);
 372   grandchild_pid = xfork ();
 373
 374   if (grandchild_pid == 0)
 375     {
 376       /* The newborn grandchild tar is here!  Launch the compressor.  */
 377
 378       set_program_name (_("tar (grandchild)"));
 379
 380       xdup2 (child_pipe[PWRITE], STDOUT_FILENO);
 381       xclose (child_pipe[PREAD]);
 382       execlp (use_compress_program_option, use_compress_program_option,
 383               (char *) 0);
 384       exec_fatal (use_compress_program_option);
 385     }
 386
 387   /* The child tar is still here!  */
 388
 389   /* Prepare for reblocking the data from the compressor into the archive.  */
 390
 391   xdup2 (child_pipe[PREAD], STDIN_FILENO);
 392   xclose (child_pipe[PWRITE]);
 393
 394   if (strcmp (archive_name_array[0], "-") == 0)
 395     archive = STDOUT_FILENO;
 396   else
 397     {
 398       archive = rmtcreat (archive_name_array[0], MODE_RW, rsh_command_option);
 399       if (archive < 0)
 400         open_fatal (archive_name_array[0]);
 401     }
 402
 403   /* Let's read out of the stdin pipe and write an archive.  */
 404
 405   while (1)
 406     {
 407       size_t status = 0;
 408       char *cursor;
 409       size_t length;
 410
 411       /* Assemble a record.  */
 412
 413       for (length = 0, cursor = record_start->buffer;
 414            length < record_size;
 415            length += status, cursor += status)
 416         {
 417           size_t size = record_size - length;
 418
 419           status = safe_read (STDIN_FILENO, cursor, size);
 420           if (status == SAFE_READ_ERROR)
 421             read_fatal (use_compress_program_option);
 422           if (status == 0)
 423             break;
 424         }
 425
 426       /* Copy the record.  */
 427
 428       if (status == 0)
 429         {
 430           /* We hit the end of the file.  Write last record at
 431              full length, as the only role of the grandchild is
 432              doing proper reblocking.  */
 433
 434           if (length > 0)
 435             {
 436               memset (record_start->buffer + length, 0, record_size - length);
 437               status = sys_write_archive_buffer ();
 438               if (status != record_size)
 439                 archive_write_error (status);
 440             }
 441
 442           /* There is nothing else to read, break out.  */
 443           break;
 444         }
 445
 446       status = sys_write_archive_buffer ();
 447       if (status != record_size)
 448         archive_write_error (status);
 449     }
 450
 451   wait_for_grandchild (grandchild_pid);
 452 }
 453
 454 /* Set ARCHIVE for uncompressing, then reading an archive.  */
 455 pid_t
 456 sys_child_open_for_uncompress (void)
 457 {
 458   int parent_pipe[2];
 459   int child_pipe[2];
 460   pid_t grandchild_pid;
 461   pid_t child_pid;
 462
 463   xpipe (parent_pipe);
 464   child_pid = xfork ();
 465
 466   if (child_pid > 0)
 467     {
 468       /* The parent tar is still here!  Just clean up.  */
 469
 470       archive = parent_pipe[PREAD];
 471       xclose (parent_pipe[PWRITE]);
 472       return child_pid;
 473     }
 474
 475   /* The newborn child tar is here!  */
 476
 477   set_program_name (_("tar (child)"));
 478   signal (SIGPIPE, SIG_DFL);
 479
 480   xdup2 (parent_pipe[PWRITE], STDOUT_FILENO);
 481   xclose (parent_pipe[PREAD]);
 482
 483   /* Check if we need a grandchild tar.  This happens only if either:
 484      a) we're reading stdin: to force unblocking;
 485      b) the file is to be accessed by rmt: compressor doesn't know how;
 486      c) the file is not a plain file.  */
 487
 488   if (strcmp (archive_name_array[0], "-") != 0
 489       && !_remdev (archive_name_array[0])
 490       && is_regular_file (archive_name_array[0]))
 491     {
 492       /* We don't need a grandchild tar.  Open the archive and lauch the
 493          uncompressor.  */
 494
 495       archive = open (archive_name_array[0], O_RDONLY | O_BINARY, MODE_RW);
 496       if (archive < 0)
 497         open_fatal (archive_name_array[0]);
 498       xdup2 (archive, STDIN_FILENO);
 499       execlp (use_compress_program_option, use_compress_program_option,
 500               "-d", (char *) 0);
 501       exec_fatal (use_compress_program_option);
 502     }
 503
 504   /* We do need a grandchild tar.  */
 505
 506   xpipe (child_pipe);
 507   grandchild_pid = xfork ();
 508
 509   if (grandchild_pid == 0)
 510     {
 511       /* The newborn grandchild tar is here!  Launch the uncompressor.  */
 512
 513       set_program_name (_("tar (grandchild)"));
 514
 515       xdup2 (child_pipe[PREAD], STDIN_FILENO);
 516       xclose (child_pipe[PWRITE]);
 517       execlp (use_compress_program_option, use_compress_program_option,
 518               "-d", (char *) 0);
 519       exec_fatal (use_compress_program_option);
 520     }
 521
 522   /* The child tar is still here!  */
 523
 524   /* Prepare for unblocking the data from the archive into the
 525      uncompressor.  */
 526
 527   xdup2 (child_pipe[PWRITE], STDOUT_FILENO);
 528   xclose (child_pipe[PREAD]);
 529
 530   if (strcmp (archive_name_array[0], "-") == 0)
 531     archive = STDIN_FILENO;
 532   else
 533     archive = rmtopen (archive_name_array[0], O_RDONLY | O_BINARY,
 534                        MODE_RW, rsh_command_option);
 535   if (archive < 0)
 536     open_fatal (archive_name_array[0]);
 537
 538   /* Let's read the archive and pipe it into stdout.  */
 539
 540   while (1)
 541     {
 542       char *cursor;
 543       size_t maximum;
 544       size_t count;
 545       size_t status;
 546
 547       clear_read_error_count ();
 548
 549     error_loop:
 550       status = rmtread (archive, record_start->buffer, record_size);
 551       if (status == SAFE_READ_ERROR)
 552         {
 553           archive_read_error ();
 554           goto error_loop;
 555         }
 556       if (status == 0)
 557         break;
 558       cursor = record_start->buffer;
 559       maximum = status;
 560       while (maximum)
 561         {
 562           count = maximum < BLOCKSIZE ? maximum : BLOCKSIZE;
 563           if (full_write (STDOUT_FILENO, cursor, count) != count)
 564             write_error (use_compress_program_option);
 565           cursor += count;
 566           maximum -= count;
 567         }
 568     }
 569
 570   xclose (STDOUT_FILENO);
 571
 572   wait_for_grandchild (grandchild_pid);
 573 }
 574
 575 \f
 576
 577 static void
 578 dec_to_env (char const *envar, uintmax_t num)
 579 {
 580   char buf[UINTMAX_STRSIZE_BOUND];
 581   char *numstr;
 582
 583   numstr = STRINGIFY_BIGINT (num, buf);
 584   if (setenv (envar, numstr, 1) != 0)
 585     xalloc_die ();
 586 }
 587
 588 static void
 589 time_to_env (char const *envar, struct timespec t)
 590 {
 591   char buf[TIMESPEC_STRSIZE_BOUND];
 592   if (setenv (envar, code_timespec (t, buf), 1) != 0)
 593     xalloc_die ();
 594 }
 595
 596 static void
 597 oct_to_env (char const *envar, unsigned long num)
 598 {
 599   char buf[1+1+(sizeof(unsigned long)*CHAR_BIT+2)/3];
 600
 601   snprintf (buf, sizeof buf, "0%lo", num);
 602   if (setenv (envar, buf, 1) != 0)
 603     xalloc_die ();
 604 }
 605
 606 static void
 607 str_to_env (char const *envar, char const *str)
 608 {
 609   if (str)
 610     {
 611       if (setenv (envar, str, 1) != 0)
 612         xalloc_die ();
 613     }
 614   else
 615     unsetenv (envar);
 616 }
 617
 618 static void
 619 chr_to_env (char const *envar, char c)
 620 {
 621   char buf[2];
 622   buf[0] = c;
 623   buf[1] = 0;
 624   if (setenv (envar, buf, 1) != 0)
 625     xalloc_die ();
 626 }
 627
 628 static void
 629 stat_to_env (char *name, char type, struct tar_stat_info *st)
 630 {
 631   str_to_env ("TAR_VERSION", PACKAGE_VERSION);
 632   str_to_env ("TAR_ARCHIVE", *archive_name_cursor);
 633   dec_to_env ("TAR_VOLUME", archive_name_cursor - archive_name_array + 1);
 634   dec_to_env ("TAR_BLOCKING_FACTOR", blocking_factor);
 635   str_to_env ("TAR_FORMAT",
 636               archive_format_string (current_format == DEFAULT_FORMAT ?
 637                                      archive_format : current_format));
 638   chr_to_env ("TAR_FILETYPE", type);
 639   oct_to_env ("TAR_MODE", st->stat.st_mode);
 640   str_to_env ("TAR_FILENAME", name);
 641   str_to_env ("TAR_REALNAME", st->file_name);
 642   str_to_env ("TAR_UNAME", st->uname);
 643   str_to_env ("TAR_GNAME", st->gname);
 644   time_to_env ("TAR_ATIME", st->atime);
 645   time_to_env ("TAR_MTIME", st->mtime);
 646   time_to_env ("TAR_CTIME", st->ctime);
 647   dec_to_env ("TAR_SIZE", st->stat.st_size);
 648   dec_to_env ("TAR_UID", st->stat.st_uid);
 649   dec_to_env ("TAR_GID", st->stat.st_gid);
 650
 651   switch (type)
 652     {
 653     case 'b':
 654     case 'c':
 655       dec_to_env ("TAR_MINOR", minor (st->stat.st_rdev));
 656       dec_to_env ("TAR_MAJOR", major (st->stat.st_rdev));
 657       unsetenv ("TAR_LINKNAME");
 658       break;
 659
 660     case 'l':
 661     case 'h':
 662       unsetenv ("TAR_MINOR");
 663       unsetenv ("TAR_MAJOR");
 664       str_to_env ("TAR_LINKNAME", st->link_name);
 665       break;
 666
 667     default:
 668       unsetenv ("TAR_MINOR");
 669       unsetenv ("TAR_MAJOR");
 670       unsetenv ("TAR_LINKNAME");
 671       break;
 672     }
 673 }
 674
 675 static pid_t global_pid;
 676 static RETSIGTYPE (*pipe_handler) (int sig);
 677
 678 int
 679 sys_exec_command (char *file_name, int typechar, struct tar_stat_info *st)
 680 {
 681   int p[2];
 682   char *argv[4];
 683
 684   xpipe (p);
 685   pipe_handler = signal (SIGPIPE, SIG_IGN);
 686   global_pid = xfork ();
 687
 688   if (global_pid != 0)
 689     {
 690       xclose (p[PREAD]);
 691       return p[PWRITE];
 692     }
 693
 694   /* Child */
 695   xdup2 (p[PREAD], STDIN_FILENO);
 696   xclose (p[PWRITE]);
 697
 698   stat_to_env (file_name, typechar, st);
 699
 700   argv[0] = "/bin/sh";
 701   argv[1] = "-c";
 702   argv[2] = to_command_option;
 703   argv[3] = NULL;
 704
 705   execv ("/bin/sh", argv);
 706
 707   exec_fatal (file_name);
 708 }
 709
 710 void
 711 sys_wait_command (void)
 712 {
 713   int status;
 714
 715   if (global_pid < 0)
 716     return;
 717
 718   signal (SIGPIPE, pipe_handler);
 719   while (waitpid (global_pid, &status, 0) == -1)
 720     if (errno != EINTR)
 721       {
 722         global_pid = -1;
 723         waitpid_error (to_command_option);
 724         return;
 725       }
 726
 727   if (WIFEXITED (status))
 728     {
 729       if (!ignore_command_error_option && WEXITSTATUS (status))
 730         ERROR ((0, 0, _("%lu: Child returned status %d"),
 731                 (unsigned long) global_pid, WEXITSTATUS (status)));
 732     }
 733   else if (WIFSIGNALED (status))
 734     {
 735       WARN ((0, 0, _("%lu: Child terminated on signal %d"),
 736              (unsigned long) global_pid, WTERMSIG (status)));
 737     }
 738   else
 739     ERROR ((0, 0, _("%lu: Child terminated on unknown reason"),
 740             (unsigned long) global_pid));
 741
 742   global_pid = -1;
 743 }
 744
 745 int
 746 sys_exec_info_script (const char **archive_name, int volume_number)
 747 {
 748   pid_t pid;
 749   char *argv[4];
 750   char uintbuf[UINTMAX_STRSIZE_BOUND];
 751   int p[2];
 752   static RETSIGTYPE (*saved_handler) (int sig);
 753
 754   xpipe (p);
 755   saved_handler = signal (SIGPIPE, SIG_IGN);
 756
 757   pid = xfork ();
 758
 759   if (pid != 0)
 760     {
 761       /* Master */
 762
 763       int rc;
 764       int status;
 765       char *buf = NULL;
 766       size_t size = 0;
 767       FILE *fp;
 768
 769       xclose (p[PWRITE]);
 770       fp = fdopen (p[PREAD], "r");
 771       rc = getline (&buf, &size, fp);
 772       fclose (fp);
 773
 774       if (rc > 0 && buf[rc-1] == '\n')
 775         buf[--rc] = 0;
 776
 777       while (waitpid (pid, &status, 0) == -1)
 778         if (errno != EINTR)
 779           {
 780             signal (SIGPIPE, saved_handler);
 781             waitpid_error (info_script_option);
 782             return -1;
 783           }
 784
 785       signal (SIGPIPE, saved_handler);
 786
 787       if (WIFEXITED (status))
 788         {
 789           if (WEXITSTATUS (status) == 0 && rc > 0)
 790             *archive_name = buf;
 791           else
 792             free (buf);
 793           return WEXITSTATUS (status);
 794         }
 795
 796       free (buf);
 797       return -1;
 798     }
 799
 800   /* Child */
 801   setenv ("TAR_VERSION", PACKAGE_VERSION, 1);
 802   setenv ("TAR_ARCHIVE", *archive_name, 1);
 803   setenv ("TAR_VOLUME", STRINGIFY_BIGINT (volume_number, uintbuf), 1);
 804   setenv ("TAR_BLOCKING_FACTOR",
 805           STRINGIFY_BIGINT (blocking_factor, uintbuf), 1);
 806   setenv ("TAR_SUBCOMMAND", subcommand_string (subcommand_option), 1);
 807   setenv ("TAR_FORMAT",
 808           archive_format_string (current_format == DEFAULT_FORMAT ?
 809                                  archive_format : current_format), 1);
 810   setenv ("TAR_FD", STRINGIFY_BIGINT (p[PWRITE], uintbuf), 1);
 811
 812   xclose (p[PREAD]);
 813
 814   argv[0] = "/bin/sh";
 815   argv[1] = "-c";
 816   argv[2] = (char *) info_script_option;
 817   argv[3] = NULL;
 818
 819   execv (argv[0], argv);
 820
 821   exec_fatal (info_script_option);
 822 }
 823
 824 void
 825 sys_exec_checkpoint_script (const char *script_name,
 826                             const char *archive_name,
 827                             int checkpoint_number)
 828 {
 829   pid_t pid;
 830   char *argv[4];
 831   char uintbuf[UINTMAX_STRSIZE_BOUND];
 832
 833   pid = xfork ();
 834
 835   if (pid != 0)
 836     {
 837       /* Master */
 838
 839       int status;
 840
 841       while (waitpid (pid, &status, 0) == -1)
 842         if (errno != EINTR)
 843           {
 844             waitpid_error (script_name);
 845             break;
 846           }
 847
 848       return;
 849     }
 850
 851   /* Child */
 852   setenv ("TAR_VERSION", PACKAGE_VERSION, 1);
 853   setenv ("TAR_ARCHIVE", archive_name, 1);
 854   setenv ("TAR_CHECKPOINT", STRINGIFY_BIGINT (checkpoint_number, uintbuf), 1);
 855   setenv ("TAR_BLOCKING_FACTOR",
 856           STRINGIFY_BIGINT (blocking_factor, uintbuf), 1);
 857   setenv ("TAR_SUBCOMMAND", subcommand_string (subcommand_option), 1);
 858   setenv ("TAR_FORMAT",
 859           archive_format_string (current_format == DEFAULT_FORMAT ?
 860                                  archive_format : current_format), 1);
 861   argv[0] = "/bin/sh";
 862   argv[1] = "-c";
 863   argv[2] = (char *) script_name;
 864   argv[3] = NULL;
 865
 866   execv (argv[0], argv);
 867
 868   exec_fatal (script_name);
 869 }
 870
 871 #endif /* not MSDOS */