build: new configure option --enable-gcc-warnings

[chaz/tar] / src / system.c

diff --git a/src/system.c b/src/system.c
index bf8e0500ef55c090c7f514625cfe1fd467ab276c..e985462dbb9360c323d497118a408c86aae8ab76 100644 (file)
--- a/src/system.c
+++ b/src/system.c
@@ -1,10 +1,11 @@
 /* System-dependent calls for tar.
 
 /* System-dependent calls for tar.
 

-   Copyright (C) 2003, 2004 Free Software Foundation, Inc.
+   Copyright (C) 2003, 2004, 2005, 2006, 2007,
+   2008, 2010 Free Software Foundation, Inc.

 
    This program is free software; you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by the
 
    This program is free software; you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by the

-   Free Software Foundation; either version 2, or (at your option) any later
+   Free Software Foundation; either version 3, or (at your option) any later

    version.
 
    This program is distributed in the hope that it will be useful, but
    version.
 
    This program is distributed in the hope that it will be useful, but


@@ -14,38 +15,15 @@
 
    You should have received a copy of the GNU General Public License along
    with this program; if not, write to the Free Software Foundation, Inc.,
 
    You should have received a copy of the GNU General Public License along
    with this program; if not, write to the Free Software Foundation, Inc.,

-   59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+   51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */

 
 #include <system.h>
 
 #include "common.h"
 
 #include <system.h>
 
 #include "common.h"

+#include <priv-set.h>

 #include <rmt.h>
 #include <signal.h>
 
 #include <rmt.h>
 #include <signal.h>
 

-void
-sys_stat_nanoseconds (struct tar_stat_info *st)
-{
-#if defined(HAVE_STRUCT_STAT_ST_SPARE1)
-  st->atime_nsec = st->stat.st_spare1 * 1000;
-  st->mtime_nsec = st->stat.st_spare2 * 1000;
-  st->ctime_nsec = st->stat.st_spare3 * 1000;
-#elif defined(HAVE_STRUCT_STAT_ST_ATIM_TV_NSEC)
-  st->atime_nsec = st->stat.st_atim.tv_nsec;
-  st->mtime_nsec = st->stat.st_mtim.tv_nsec;
-  st->ctime_nsec = st->stat.st_ctim.tv_nsec;
-#elif defined(HAVE_STRUCT_STAT_ST_ATIMESPEC_TV_NSEC)
-  st->atime_nsec = st->stat.st_atimespec.tv_nsec;
-  st->mtime_nsec = st->stat.st_mtimespec.tv_nsec;
-  st->ctime_nsec = st->stat.st_ctimespec.tv_nsec;
-#elif defined(HAVE_STRUCT_STAT_ST_ATIMENSEC)
-  st->atime_nsec = st->stat.st_atimensec;
-  st->mtime_nsec = st->stat.st_mtimensec;
-  st->ctime_nsec = st->stat.st_ctimensec;
-#else
-  st->atime_nsec  = st->mtime_nsec = st->ctime_nsec = 0;
-#endif
-}
-

 #if MSDOS
 
 bool
 #if MSDOS
 
 bool


@@ -75,12 +53,7 @@ sys_detect_dev_null_output (void)
 }
 
 void
 }
 
 void

-sys_drain_input_pipe (void)
-{
-}
-
-void
-sys_wait_for_child (pid_t child_pid)
+sys_wait_for_child (pid_t child_pid, bool eof)

 {
 }
 
 {
 }
 


@@ -184,26 +157,8 @@ sys_detect_dev_null_output (void)
                         && archive_stat.st_ino == dev_null_stat.st_ino));
 }
 
                         && archive_stat.st_ino == dev_null_stat.st_ino));
 }
 

-/* Manage to fully drain a pipe we might be reading, so to not break it on
-   the producer after the EOF block.  FIXME: one of these days, GNU tar
-   might become clever enough to just stop working, once there is no more
-   work to do, we might have to revise this area in such time.  */
-
-void
-sys_drain_input_pipe (void)
-{
-  size_t r;
-
-  if (access_mode == ACCESS_READ
-      && ! _isrmt (archive)
-      && (S_ISFIFO (archive_stat.st_mode) || S_ISSOCK (archive_stat.st_mode)))
-    while ((r = rmtread (archive, record_start->buffer, record_size)) != 0
-          && r != SAFE_READ_ERROR)
-      continue;
-}
-

 void
 void

-sys_wait_for_child (pid_t child_pid)
+sys_wait_for_child (pid_t child_pid, bool eof)

 {
   if (child_pid)
     {
 {
   if (child_pid)
     {


@@ -217,11 +172,14 @@ sys_wait_for_child (pid_t child_pid)
          }
 
       if (WIFSIGNALED (wait_status))
          }
 
       if (WIFSIGNALED (wait_status))

-       ERROR ((0, 0, _("Child died with signal %d"),
-               WTERMSIG (wait_status)));
+       {
+         int sig = WTERMSIG (wait_status);
+         if (!(!eof && sig == SIGPIPE))
+           FATAL_ERROR ((0, 0, _("Child died with signal %d"), sig));
+       }

       else if (WEXITSTATUS (wait_status) != 0)
       else if (WEXITSTATUS (wait_status) != 0)

-       ERROR ((0, 0, _("Child returned status %d"),
-               WEXITSTATUS (wait_status)));
+       FATAL_ERROR ((0, 0, _("Child returned status %d"),
+                     WEXITSTATUS (wait_status)));

     }
 }
 
     }
 }
 


@@ -235,6 +193,7 @@ sys_spawn_shell (void)
   child = xfork ();
   if (child == 0)
     {
   child = xfork ();
   if (child == 0)
     {

+      priv_set_restore_linkdir ();

       execlp (shell, "-sh", "-i", (char *) 0);
       exec_fatal (shell);
     }
       execlp (shell, "-sh", "-i", (char *) 0);
       exec_fatal (shell);
     }


@@ -326,6 +285,30 @@ xdup2 (int from, int into)
     }
 }
 
     }
 }
 

+static void wait_for_grandchild (pid_t pid) __attribute__ ((__noreturn__));
+
+/* Propagate any failure of the grandchild back to the parent.  */
+static void
+wait_for_grandchild (pid_t pid)
+{
+  int wait_status;
+  int exit_code = 0;
+
+  while (waitpid (pid, &wait_status, 0) == -1)
+    if (errno != EINTR)
+      {
+       waitpid_error (use_compress_program_option);
+       break;
+      }
+
+  if (WIFSIGNALED (wait_status))
+    raise (WTERMSIG (wait_status));
+  else if (WEXITSTATUS (wait_status) != 0)
+    exit_code = WEXITSTATUS (wait_status);
+
+  exit (exit_code);
+}
+

 /* Set ARCHIVE for writing, then compressing an archive.  */
 pid_t
 sys_child_open_for_compress (void)
 /* Set ARCHIVE for writing, then compressing an archive.  */
 pid_t
 sys_child_open_for_compress (void)


@@ -334,7 +317,6 @@ sys_child_open_for_compress (void)
   int child_pipe[2];
   pid_t grandchild_pid;
   pid_t child_pid;
   int child_pipe[2];
   pid_t grandchild_pid;
   pid_t child_pid;

-  int wait_status;

 
   xpipe (parent_pipe);
   child_pid = xfork ();
 
   xpipe (parent_pipe);
   child_pid = xfork ();


@@ -350,18 +332,17 @@ sys_child_open_for_compress (void)
 
   /* The new born child tar is here!  */
 
 
   /* The new born child tar is here!  */
 

-  program_name = _("tar (child)");
+  set_program_name (_("tar (child)"));
+  signal (SIGPIPE, SIG_DFL);

 
   xdup2 (parent_pipe[PREAD], STDIN_FILENO);
   xclose (parent_pipe[PWRITE]);
 
   /* Check if we need a grandchild tar.  This happens only if either:
 
   xdup2 (parent_pipe[PREAD], STDIN_FILENO);
   xclose (parent_pipe[PWRITE]);
 
   /* Check if we need a grandchild tar.  This happens only if either:

-     a) we are writing stdout: to force reblocking;
-     b) the file is to be accessed by rmt: compressor doesn't know how;
-     c) the file is not a plain file.  */
+     a) the file is to be accessed by rmt: compressor doesn't know how;
+     b) the file is not a plain file.  */

 
 

-  if (strcmp (archive_name_array[0], "-") != 0
-      && !_remdev (archive_name_array[0])
+  if (!_remdev (archive_name_array[0])

       && is_regular_file (archive_name_array[0]))
     {
       if (backup_option)
       && is_regular_file (archive_name_array[0]))
     {
       if (backup_option)


@@ -369,20 +350,22 @@ sys_child_open_for_compress (void)
 
       /* We don't need a grandchild tar.  Open the archive and launch the
         compressor.  */
 
       /* We don't need a grandchild tar.  Open the archive and launch the
         compressor.  */

-
-      archive = creat (archive_name_array[0], MODE_RW);
-      if (archive < 0)
+      if (strcmp (archive_name_array[0], "-"))

        {
        {

-         int saved_errno = errno;
+         archive = creat (archive_name_array[0], MODE_RW);
+         if (archive < 0)
+           {
+             int saved_errno = errno;

 
 

-         if (backup_option)
-           undo_last_backup ();
-         errno = saved_errno;
-         open_fatal (archive_name_array[0]);
+             if (backup_option)
+               undo_last_backup ();
+             errno = saved_errno;
+             open_fatal (archive_name_array[0]);
+           }
+         xdup2 (archive, STDOUT_FILENO);

        }
        }

-      xdup2 (archive, STDOUT_FILENO);
-      execlp (use_compress_program_option, use_compress_program_option,
-             (char *) 0);
+      priv_set_restore_linkdir ();
+      execlp (use_compress_program_option, use_compress_program_option, NULL);

       exec_fatal (use_compress_program_option);
     }
 
       exec_fatal (use_compress_program_option);
     }
 


@@ -395,10 +378,11 @@ sys_child_open_for_compress (void)
     {
       /* The newborn grandchild tar is here!  Launch the compressor.  */
 
     {
       /* The newborn grandchild tar is here!  Launch the compressor.  */
 

-      program_name = _("tar (grandchild)");
+      set_program_name (_("tar (grandchild)"));

 
       xdup2 (child_pipe[PWRITE], STDOUT_FILENO);
       xclose (child_pipe[PREAD]);
 
       xdup2 (child_pipe[PWRITE], STDOUT_FILENO);
       xclose (child_pipe[PREAD]);

+      priv_set_restore_linkdir ();

       execlp (use_compress_program_option, use_compress_program_option,
              (char *) 0);
       exec_fatal (use_compress_program_option);
       execlp (use_compress_program_option, use_compress_program_option,
              (char *) 0);
       exec_fatal (use_compress_program_option);


@@ -468,24 +452,30 @@ sys_child_open_for_compress (void)
        archive_write_error (status);
     }
 
        archive_write_error (status);
     }
 

-  /* Propagate any failure of the grandchild back to the parent.  */
+  wait_for_grandchild (grandchild_pid);
+}

 
 

-  while (waitpid (grandchild_pid, &wait_status, 0) == -1)
-    if (errno != EINTR)
-      {
-       waitpid_error (use_compress_program_option);
-       break;
-      }
+static void
+run_decompress_program (void)
+{
+  int i;
+  const char *p, *prog = NULL;

 
 

-  if (WIFSIGNALED (wait_status))
+  for (p = first_decompress_program (&i); p; p = next_decompress_program (&i))

     {
     {

-      kill (child_pid, WTERMSIG (wait_status));
-      exit_status = TAREXIT_FAILURE;
+      if (prog)
+       {
+         WARNOPT (WARN_DECOMPRESS_PROGRAM,
+                  (0, errno, _("cannot run %s"), prog));
+         WARNOPT (WARN_DECOMPRESS_PROGRAM,
+                  (0, 0, _("trying %s"), p));
+       }
+      prog = p;
+      execlp (p, p, "-d", NULL);

     }
     }

-  else if (WEXITSTATUS (wait_status) != 0)
-    exit_status = WEXITSTATUS (wait_status);
-
-  exit (exit_status);
+  if (!prog)
+    FATAL_ERROR ((0, 0, _("unable to run decompression program")));
+  exec_fatal (prog);

 }
 
 /* Set ARCHIVE for uncompressing, then reading an archive.  */
 }
 
 /* Set ARCHIVE for uncompressing, then reading an archive.  */


@@ -496,7 +486,6 @@ sys_child_open_for_uncompress (void)
   int child_pipe[2];
   pid_t grandchild_pid;
   pid_t child_pid;
   int child_pipe[2];
   pid_t grandchild_pid;
   pid_t child_pid;

-  int wait_status;

 
   xpipe (parent_pipe);
   child_pid = xfork ();
 
   xpipe (parent_pipe);
   child_pid = xfork ();


@@ -512,7 +501,8 @@ sys_child_open_for_uncompress (void)
 
   /* The newborn child tar is here!  */
 
 
   /* The newborn child tar is here!  */
 

-  program_name = _("tar (child)");
+  set_program_name (_("tar (child)"));
+  signal (SIGPIPE, SIG_DFL);

 
   xdup2 (parent_pipe[PWRITE], STDOUT_FILENO);
   xclose (parent_pipe[PREAD]);
 
   xdup2 (parent_pipe[PWRITE], STDOUT_FILENO);
   xclose (parent_pipe[PREAD]);


@@ -533,9 +523,8 @@ sys_child_open_for_uncompress (void)
       if (archive < 0)
        open_fatal (archive_name_array[0]);
       xdup2 (archive, STDIN_FILENO);
       if (archive < 0)
        open_fatal (archive_name_array[0]);
       xdup2 (archive, STDIN_FILENO);

-      execlp (use_compress_program_option, use_compress_program_option,
-             "-d", (char *) 0);
-      exec_fatal (use_compress_program_option);
+      priv_set_restore_linkdir ();
+      run_decompress_program ();

     }
 
   /* We do need a grandchild tar.  */
     }
 
   /* We do need a grandchild tar.  */


@@ -547,13 +536,12 @@ sys_child_open_for_uncompress (void)
     {
       /* The newborn grandchild tar is here!  Launch the uncompressor.  */
 
     {
       /* The newborn grandchild tar is here!  Launch the uncompressor.  */
 

-      program_name = _("tar (grandchild)");
+      set_program_name (_("tar (grandchild)"));

 
       xdup2 (child_pipe[PREAD], STDIN_FILENO);
       xclose (child_pipe[PWRITE]);
 
       xdup2 (child_pipe[PREAD], STDIN_FILENO);
       xclose (child_pipe[PWRITE]);

-      execlp (use_compress_program_option, use_compress_program_option,
-             "-d", (char *) 0);
-      exec_fatal (use_compress_program_option);
+      priv_set_restore_linkdir ();
+      run_decompress_program ();

     }
 
   /* The child tar is still here!  */
     }
 
   /* The child tar is still here!  */


@@ -606,80 +594,84 @@ sys_child_open_for_uncompress (void)
 
   xclose (STDOUT_FILENO);
 
 
   xclose (STDOUT_FILENO);
 

-  /* Propagate any failure of the grandchild back to the parent.  */
-
-  while (waitpid (grandchild_pid, &wait_status, 0) == -1)
-    if (errno != EINTR)
-      {
-       waitpid_error (use_compress_program_option);
-       break;
-      }
-
-  if (WIFSIGNALED (wait_status))
-    {
-      kill (child_pid, WTERMSIG (wait_status));
-      exit_status = TAREXIT_FAILURE;
-    }
-  else if (WEXITSTATUS (wait_status) != 0)
-    exit_status = WEXITSTATUS (wait_status);
-
-  exit (exit_status);
+  wait_for_grandchild (grandchild_pid);

 }
 
 \f
 
 static void
 }
 
 \f
 
 static void

-dec_to_env (char *envar, uintmax_t num)
+dec_to_env (char const *envar, uintmax_t num)

 {
   char buf[UINTMAX_STRSIZE_BOUND];
   char *numstr;
 
   numstr = STRINGIFY_BIGINT (num, buf);
 {
   char buf[UINTMAX_STRSIZE_BOUND];
   char *numstr;
 
   numstr = STRINGIFY_BIGINT (num, buf);

-  setenv (envar, numstr, 1);
+  if (setenv (envar, numstr, 1) != 0)
+    xalloc_die ();

 }
 
 static void
 }
 
 static void

-oct_to_env (char *envar, unsigned long num)
+time_to_env (char const *envar, struct timespec t)
+{
+  char buf[TIMESPEC_STRSIZE_BOUND];
+  if (setenv (envar, code_timespec (t, buf), 1) != 0)
+    xalloc_die ();
+}
+
+static void
+oct_to_env (char const *envar, unsigned long num)

 {
   char buf[1+1+(sizeof(unsigned long)*CHAR_BIT+2)/3];
 {
   char buf[1+1+(sizeof(unsigned long)*CHAR_BIT+2)/3];

-  
+

   snprintf (buf, sizeof buf, "0%lo", num);
   snprintf (buf, sizeof buf, "0%lo", num);

-  setenv (envar, buf, 1);
+  if (setenv (envar, buf, 1) != 0)
+    xalloc_die ();

 }
 
 static void
 }
 
 static void

-str_to_env (char *envar, char const *str)
+str_to_env (char const *envar, char const *str)

 {
   if (str)
 {
   if (str)

-    setenv (envar, str, 1);
+    {
+      if (setenv (envar, str, 1) != 0)
+       xalloc_die ();
+    }

   else
     unsetenv (envar);
 }
 
 static void
   else
     unsetenv (envar);
 }
 
 static void

-chr_to_env (char *envar, char c)
+chr_to_env (char const *envar, char c)

 {
   char buf[2];
   buf[0] = c;
   buf[1] = 0;
 {
   char buf[2];
   buf[0] = c;
   buf[1] = 0;

-  setenv (envar, buf, 1);
+  if (setenv (envar, buf, 1) != 0)
+    xalloc_die ();

 }
 
 static void
 stat_to_env (char *name, char type, struct tar_stat_info *st)
 {
 }
 
 static void
 stat_to_env (char *name, char type, struct tar_stat_info *st)
 {

+  str_to_env ("TAR_VERSION", PACKAGE_VERSION);
+  str_to_env ("TAR_ARCHIVE", *archive_name_cursor);
+  dec_to_env ("TAR_VOLUME", archive_name_cursor - archive_name_array + 1);
+  dec_to_env ("TAR_BLOCKING_FACTOR", blocking_factor);
+  str_to_env ("TAR_FORMAT",
+             archive_format_string (current_format == DEFAULT_FORMAT ?
+                                    archive_format : current_format));

   chr_to_env ("TAR_FILETYPE", type);
   oct_to_env ("TAR_MODE", st->stat.st_mode);
   str_to_env ("TAR_FILENAME", name);
   str_to_env ("TAR_REALNAME", st->file_name);
   str_to_env ("TAR_UNAME", st->uname);
   str_to_env ("TAR_GNAME", st->gname);
   chr_to_env ("TAR_FILETYPE", type);
   oct_to_env ("TAR_MODE", st->stat.st_mode);
   str_to_env ("TAR_FILENAME", name);
   str_to_env ("TAR_REALNAME", st->file_name);
   str_to_env ("TAR_UNAME", st->uname);
   str_to_env ("TAR_GNAME", st->gname);

-  dec_to_env ("TAR_MTIME", st->stat.st_mtime);
-  dec_to_env ("TAR_ATIME", st->stat.st_atime);
-  dec_to_env ("TAR_CTIME", st->stat.st_ctime);
+  time_to_env ("TAR_ATIME", st->atime);
+  time_to_env ("TAR_MTIME", st->mtime);
+  time_to_env ("TAR_CTIME", st->ctime);

   dec_to_env ("TAR_SIZE", st->stat.st_size);
   dec_to_env ("TAR_UID", st->stat.st_uid);
   dec_to_env ("TAR_SIZE", st->stat.st_size);
   dec_to_env ("TAR_UID", st->stat.st_uid);

-  dec_to_env ("TAR_GID", st->stat.st_gid);     
+  dec_to_env ("TAR_GID", st->stat.st_gid);

 
   switch (type)
     {
 
   switch (type)
     {


@@ -705,7 +697,7 @@ stat_to_env (char *name, char type, struct tar_stat_info *st)
     }
 }
 
     }
 }
 

-static pid_t pid;
+static pid_t global_pid;

 static RETSIGTYPE (*pipe_handler) (int sig);
 
 int
 static RETSIGTYPE (*pipe_handler) (int sig);
 
 int


@@ -713,12 +705,12 @@ sys_exec_command (char *file_name, int typechar, struct tar_stat_info *st)
 {
   int p[2];
   char *argv[4];
 {
   int p[2];
   char *argv[4];

-  
+

   xpipe (p);
   pipe_handler = signal (SIGPIPE, SIG_IGN);
   xpipe (p);
   pipe_handler = signal (SIGPIPE, SIG_IGN);

-  pid = xfork ();
+  global_pid = xfork ();

 
 

-  if (pid != 0)
+  if (global_pid != 0)

     {
       xclose (p[PREAD]);
       return p[PWRITE];
     {
       xclose (p[PREAD]);
       return p[PWRITE];


@@ -727,14 +719,15 @@ sys_exec_command (char *file_name, int typechar, struct tar_stat_info *st)
   /* Child */
   xdup2 (p[PREAD], STDIN_FILENO);
   xclose (p[PWRITE]);
   /* Child */
   xdup2 (p[PREAD], STDIN_FILENO);
   xclose (p[PWRITE]);

-  
+

   stat_to_env (file_name, typechar, st);
 
   stat_to_env (file_name, typechar, st);
 

-  argv[0] = "/bin/sh";
-  argv[1] = "-c";
+  argv[0] = (char *) "/bin/sh";
+  argv[1] = (char *) "-c";

   argv[2] = to_command_option;
   argv[3] = NULL;
 
   argv[2] = to_command_option;
   argv[3] = NULL;
 

+  priv_set_restore_linkdir ();

   execv ("/bin/sh", argv);
 
   exec_fatal (file_name);
   execv ("/bin/sh", argv);
 
   exec_fatal (file_name);


@@ -744,15 +737,15 @@ void
 sys_wait_command (void)
 {
   int status;
 sys_wait_command (void)
 {
   int status;

-  
-  if (pid < 0)
+
+  if (global_pid < 0)

     return;
 
   signal (SIGPIPE, pipe_handler);
     return;
 
   signal (SIGPIPE, pipe_handler);

-  while (waitpid (pid, &status, 0) == -1)
+  while (waitpid (global_pid, &status, 0) == -1)

     if (errno != EINTR)
       {
     if (errno != EINTR)
       {

-        pid = -1;
+        global_pid = -1;

         waitpid_error (to_command_option);
         return;
       }
         waitpid_error (to_command_option);
         return;
       }


@@ -761,19 +754,146 @@ sys_wait_command (void)
     {
       if (!ignore_command_error_option && WEXITSTATUS (status))
        ERROR ((0, 0, _("%lu: Child returned status %d"),
     {
       if (!ignore_command_error_option && WEXITSTATUS (status))
        ERROR ((0, 0, _("%lu: Child returned status %d"),

-               (unsigned long) pid, WEXITSTATUS (status)));
+               (unsigned long) global_pid, WEXITSTATUS (status)));

     }
   else if (WIFSIGNALED (status))
     {
       WARN ((0, 0, _("%lu: Child terminated on signal %d"),
     }
   else if (WIFSIGNALED (status))
     {
       WARN ((0, 0, _("%lu: Child terminated on signal %d"),

-            (unsigned long) pid, WTERMSIG (status)));
+            (unsigned long) global_pid, WTERMSIG (status)));

     }
   else
     ERROR ((0, 0, _("%lu: Child terminated on unknown reason"),
     }
   else
     ERROR ((0, 0, _("%lu: Child terminated on unknown reason"),

-           (unsigned long) pid));
+           (unsigned long) global_pid));

 
 

-  pid = -1;
+  global_pid = -1;

 }
 
 }
 

-#endif /* not MSDOS */
+int
+sys_exec_info_script (const char **archive_name, int volume_number)
+{
+  pid_t pid;
+  char *argv[4];
+  char uintbuf[UINTMAX_STRSIZE_BOUND];
+  int p[2];
+  static RETSIGTYPE (*saved_handler) (int sig);
+
+  xpipe (p);
+  saved_handler = signal (SIGPIPE, SIG_IGN);
+
+  pid = xfork ();
+
+  if (pid != 0)
+    {
+      /* Master */
+
+      int rc;
+      int status;
+      char *buf = NULL;
+      size_t size = 0;
+      FILE *fp;
+
+      xclose (p[PWRITE]);
+      fp = fdopen (p[PREAD], "r");
+      rc = getline (&buf, &size, fp);
+      fclose (fp);
+
+      if (rc > 0 && buf[rc-1] == '\n')
+       buf[--rc] = 0;
+
+      while (waitpid (pid, &status, 0) == -1)
+       if (errno != EINTR)
+         {
+           signal (SIGPIPE, saved_handler);
+           waitpid_error (info_script_option);
+           return -1;
+         }
+
+      signal (SIGPIPE, saved_handler);

 
 

+      if (WIFEXITED (status))
+       {
+         if (WEXITSTATUS (status) == 0 && rc > 0)
+           *archive_name = buf;
+         else
+           free (buf);
+         return WEXITSTATUS (status);
+       }
+
+      free (buf);
+      return -1;
+    }
+
+  /* Child */
+  setenv ("TAR_VERSION", PACKAGE_VERSION, 1);
+  setenv ("TAR_ARCHIVE", *archive_name, 1);
+  setenv ("TAR_VOLUME", STRINGIFY_BIGINT (volume_number, uintbuf), 1);
+  setenv ("TAR_BLOCKING_FACTOR",
+         STRINGIFY_BIGINT (blocking_factor, uintbuf), 1);
+  setenv ("TAR_SUBCOMMAND", subcommand_string (subcommand_option), 1);
+  setenv ("TAR_FORMAT",
+         archive_format_string (current_format == DEFAULT_FORMAT ?
+                                archive_format : current_format), 1);
+  setenv ("TAR_FD", STRINGIFY_BIGINT (p[PWRITE], uintbuf), 1);
+
+  xclose (p[PREAD]);
+
+  argv[0] = (char *) "/bin/sh";
+  argv[1] = (char *) "-c";
+  argv[2] = (char *) info_script_option;
+  argv[3] = NULL;
+
+  priv_set_restore_linkdir ();
+  execv (argv[0], argv);
+
+  exec_fatal (info_script_option);
+}
+
+void
+sys_exec_checkpoint_script (const char *script_name,
+                           const char *archive_name,
+                           int checkpoint_number)
+{
+  pid_t pid;
+  char *argv[4];
+  char uintbuf[UINTMAX_STRSIZE_BOUND];
+
+  pid = xfork ();
+
+  if (pid != 0)
+    {
+      /* Master */
+
+      int status;
+
+      while (waitpid (pid, &status, 0) == -1)
+       if (errno != EINTR)
+         {
+           waitpid_error (script_name);
+           break;
+         }
+
+      return;
+    }
+
+  /* Child */
+  setenv ("TAR_VERSION", PACKAGE_VERSION, 1);
+  setenv ("TAR_ARCHIVE", archive_name, 1);
+  setenv ("TAR_CHECKPOINT", STRINGIFY_BIGINT (checkpoint_number, uintbuf), 1);
+  setenv ("TAR_BLOCKING_FACTOR",
+         STRINGIFY_BIGINT (blocking_factor, uintbuf), 1);
+  setenv ("TAR_SUBCOMMAND", subcommand_string (subcommand_option), 1);
+  setenv ("TAR_FORMAT",
+         archive_format_string (current_format == DEFAULT_FORMAT ?
+                                archive_format : current_format), 1);
+  argv[0] = (char *) "/bin/sh";
+  argv[1] = (char *) "-c";
+  argv[2] = (char *) script_name;
+  argv[3] = NULL;
+
+  priv_set_restore_linkdir ();
+  execv (argv[0], argv);
+
+  exec_fatal (script_name);
+}
+
+#endif /* not MSDOS */