+\f
+
+static void
+dec_to_env (char *envar, uintmax_t num)
+{
+ char buf[UINTMAX_STRSIZE_BOUND];
+ char *numstr;
+
+ numstr = STRINGIFY_BIGINT (num, buf);
+ if (setenv (envar, numstr, 1) != 0)
+ xalloc_die ();
+}
+
+static void
+time_to_env (char *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 *envar, unsigned long num)
+{
+ char buf[1+1+(sizeof(unsigned long)*CHAR_BIT+2)/3];
+
+ snprintf (buf, sizeof buf, "0%lo", num);
+ if (setenv (envar, buf, 1) != 0)
+ xalloc_die ();
+}
+
+static void
+str_to_env (char *envar, char const *str)
+{
+ if (str)
+ {
+ if (setenv (envar, str, 1) != 0)
+ xalloc_die ();
+ }
+ else
+ unsetenv (envar);
+}
+
+static void
+chr_to_env (char *envar, char c)
+{
+ char buf[2];
+ buf[0] = c;
+ buf[1] = 0;
+ if (setenv (envar, buf, 1) != 0)
+ xalloc_die ();
+}
+
+static void
+stat_to_env (char *name, char type, struct tar_stat_info *st)
+{
+ 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);
+ 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_GID", st->stat.st_gid);
+
+ switch (type)
+ {
+ case 'b':
+ case 'c':
+ dec_to_env ("TAR_MINOR", minor (st->stat.st_rdev));
+ dec_to_env ("TAR_MAJOR", major (st->stat.st_rdev));
+ unsetenv ("TAR_LINKNAME");
+ break;
+
+ case 'l':
+ case 'h':
+ unsetenv ("TAR_MINOR");
+ unsetenv ("TAR_MAJOR");
+ str_to_env ("TAR_LINKNAME", st->link_name);
+ break;
+
+ default:
+ unsetenv ("TAR_MINOR");
+ unsetenv ("TAR_MAJOR");
+ unsetenv ("TAR_LINKNAME");
+ break;
+ }
+}
+
+static pid_t pid;
+static RETSIGTYPE (*pipe_handler) (int sig);
+
+int
+sys_exec_command (char *file_name, int typechar, struct tar_stat_info *st)
+{
+ int p[2];
+ char *argv[4];
+
+ xpipe (p);
+ pipe_handler = signal (SIGPIPE, SIG_IGN);
+ pid = xfork ();
+
+ if (pid != 0)
+ {
+ xclose (p[PREAD]);
+ return p[PWRITE];
+ }
+
+ /* Child */
+ xdup2 (p[PREAD], STDIN_FILENO);
+ xclose (p[PWRITE]);
+
+ stat_to_env (file_name, typechar, st);
+
+ argv[0] = "/bin/sh";
+ argv[1] = "-c";
+ argv[2] = to_command_option;
+ argv[3] = NULL;