gnu/dist/gettext/gettext-tools/lib/execute.c

   1 /* Creation of autonomous subprocesses.
   2    Copyright (C) 2001-2004 Free Software Foundation, Inc.
   3    Written by Bruno Haible <haible@clisp.cons.org>, 2001.
   4
   5    This program is free software; you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 2, or (at your option)
   8    any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program; if not, write to the Free Software Foundation,
  17    Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  18
  19
  20 #ifdef HAVE_CONFIG_H
  21 # include "config.h"
  22 #endif
  23
  24 /* Specification.  */
  25 #include "execute.h"
  26
  27 #include <errno.h>
  28 #include <fcntl.h>
  29 #include <stdbool.h>
  30 #include <stdlib.h>
  31 #include <signal.h>
  32
  33 #ifdef HAVE_UNISTD_H
  34 # include <unistd.h>
  35 #endif
  36
  37 #include "error.h"
  38 #include "exit.h"
  39 #include "fatal-signal.h"
  40 #include "wait-process.h"
  41 #include "gettext.h"
  42
  43 #define _(str) gettext (str)
  44
  45 #if defined _MSC_VER || defined __MINGW32__
  46
  47 /* Native Woe32 API.  */
  48 # include <process.h>
  49 # include "w32spawn.h"
  50
  51 #else
  52
  53 /* Unix API.  */
  54 # ifdef HAVE_POSIX_SPAWN
  55 #  include <spawn.h>
  56 # else
  57 #  ifdef HAVE_VFORK_H
  58 #   include <vfork.h>
  59 #  endif
  60 # endif
  61
  62 #endif
  63
  64 #ifndef HAVE_ENVIRON_DECL
  65 extern char **environ;
  66 #endif
  67
  68 #ifndef STDIN_FILENO
  69 # define STDIN_FILENO 0
  70 #endif
  71 #ifndef STDOUT_FILENO
  72 # define STDOUT_FILENO 1
  73 #endif
  74 #ifndef STDERR_FILENO
  75 # define STDERR_FILENO 2
  76 #endif
  77
  78
  79 #ifdef EINTR
  80
  81 /* EINTR handling for close(), open().
  82    These functions can return -1/EINTR even though we don't have any
  83    signal handlers set up, namely when we get interrupted via SIGSTOP.  */
  84
  85 static inline int
  86 nonintr_close (int fd)
  87 {
  88   int retval;
  89
  90   do
  91     retval = close (fd);
  92   while (retval < 0 && errno == EINTR);
  93
  94   return retval;
  95 }
  96 #define close nonintr_close
  97
  98 static inline int
  99 nonintr_open (const char *pathname, int oflag, mode_t mode)
 100 {
 101   int retval;
 102
 103   do
 104     retval = open (pathname, oflag, mode);
 105   while (retval < 0 && errno == EINTR);
 106
 107   return retval;
 108 }
 109 #undef open /* avoid warning on VMS */
 110 #define open nonintr_open
 111
 112 #endif
 113
 114
 115 /* Execute a command, optionally redirecting any of the three standard file
 116    descriptors to /dev/null.  Return its exit code.
 117    If it didn't terminate correctly, exit if exit_on_error is true, otherwise
 118    return 127.
 119    If slave_process is true, the child process will be terminated when its
 120    creator receives a catchable fatal signal.  */
 121 int
 122 execute (const char *progname,
 123          const char *prog_path, char **prog_argv,
 124          bool ignore_sigpipe,
 125          bool null_stdin, bool null_stdout, bool null_stderr,
 126          bool slave_process, bool exit_on_error)
 127 {
 128 #if defined _MSC_VER || defined __MINGW32__
 129
 130   /* Native Woe32 API.  */
 131   int orig_stdin;
 132   int orig_stdout;
 133   int orig_stderr;
 134   int exitcode;
 135   int nullinfd;
 136   int nulloutfd;
 137
 138   prog_argv = prepare_spawn (prog_argv);
 139
 140   /* Save standard file handles of parent process.  */
 141   if (null_stdin)
 142     orig_stdin = dup_noinherit (STDIN_FILENO);
 143   if (null_stdout)
 144     orig_stdout = dup_noinherit (STDOUT_FILENO);
 145   if (null_stderr)
 146     orig_stderr = dup_noinherit (STDERR_FILENO);
 147   exitcode = -1;
 148
 149   /* Create standard file handles of child process.  */
 150   nullinfd = -1;
 151   nulloutfd = -1;
 152   if ((!null_stdin
 153        || ((nullinfd = open ("NUL", O_RDONLY, 0)) >= 0
 154            && (nullinfd == STDIN_FILENO
 155                || (dup2 (nullinfd, STDIN_FILENO) >= 0
 156                    && close (nullinfd) >= 0))))
 157       && (!(null_stdout || null_stderr)
 158           || ((nulloutfd = open ("NUL", O_RDWR, 0)) >= 0
 159               && (!null_stdout
 160                   || nulloutfd == STDOUT_FILENO
 161                   || dup2 (nulloutfd, STDOUT_FILENO) >= 0)
 162               && (!null_stderr
 163                   || nulloutfd == STDERR_FILENO
 164                   || dup2 (nulloutfd, STDERR_FILENO) >= 0)
 165               && ((null_stdout && nulloutfd == STDOUT_FILENO)
 166                   || (null_stderr && nulloutfd == STDERR_FILENO)
 167                   || close (nulloutfd) >= 0))))
 168     exitcode = spawnvp (P_WAIT, prog_path, prog_argv);
 169   if (nulloutfd >= 0)
 170     close (nulloutfd);
 171   if (nullinfd >= 0)
 172     close (nullinfd);
 173
 174   /* Restore standard file handles of parent process.  */
 175   if (null_stderr)
 176     dup2 (orig_stderr, STDERR_FILENO), close (orig_stderr);
 177   if (null_stdout)
 178     dup2 (orig_stdout, STDOUT_FILENO), close (orig_stdout);
 179   if (null_stdin)
 180     dup2 (orig_stdin, STDIN_FILENO), close (orig_stdin);
 181
 182   if (exitcode == -1)
 183     {
 184       if (exit_on_error || !null_stderr)
 185         error (exit_on_error ? EXIT_FAILURE : 0, errno,
 186                _("%s subprocess failed"), progname);
 187       return 127;
 188     }
 189
 190   return exitcode;
 191
 192 #else
 193
 194   /* Unix API.  */
 195   /* Note about 127: Some errors during posix_spawnp() cause the function
 196      posix_spawnp() to return an error code; some other errors cause the
 197      subprocess to exit with return code 127.  It is implementation
 198      dependent which error is reported which way.  We treat both cases as
 199      equivalent.  */
 200 #if HAVE_POSIX_SPAWN
 201   sigset_t blocked_signals;
 202   posix_spawn_file_actions_t actions;
 203   bool actions_allocated;
 204   posix_spawnattr_t attrs;
 205   bool attrs_allocated;
 206   int err;
 207   pid_t child;
 208 #else
 209   int child;
 210 #endif
 211
 212 #if HAVE_POSIX_SPAWN
 213   if (slave_process)
 214     {
 215       sigprocmask (SIG_SETMASK, NULL, &blocked_signals);
 216       block_fatal_signals ();
 217     }
 218   actions_allocated = false;
 219   attrs_allocated = false;
 220   if ((err = posix_spawn_file_actions_init (&actions)) != 0
 221       || (actions_allocated = true,
 222           (null_stdin
 223             && (err = posix_spawn_file_actions_addopen (&actions,
 224                                                         STDIN_FILENO,
 225                                                         "/dev/null", O_RDONLY,
 226                                                         0))
 227                != 0)
 228           || (null_stdout
 229               && (err = posix_spawn_file_actions_addopen (&actions,
 230                                                           STDOUT_FILENO,
 231                                                           "/dev/null", O_RDWR,
 232                                                           0))
 233                  != 0)
 234           || (null_stderr
 235               && (err = posix_spawn_file_actions_addopen (&actions,
 236                                                           STDERR_FILENO,
 237                                                           "/dev/null", O_RDWR,
 238                                                           0))
 239                  != 0)
 240           || (slave_process
 241               && ((err = posix_spawnattr_init (&attrs)) != 0
 242                   || (attrs_allocated = true,
 243                       (err = posix_spawnattr_setsigmask (&attrs,
 244                                                          &blocked_signals))
 245                       != 0
 246                       || (err = posix_spawnattr_setflags (&attrs,
 247                                                         POSIX_SPAWN_SETSIGMASK))
 248                          != 0)))
 249           || (err = posix_spawnp (&child, prog_path, &actions,
 250                                   attrs_allocated ? &attrs : NULL, prog_argv,
 251                                   environ))
 252              != 0))
 253     {
 254       if (actions_allocated)
 255         posix_spawn_file_actions_destroy (&actions);
 256       if (attrs_allocated)
 257         posix_spawnattr_destroy (&attrs);
 258       if (slave_process)
 259         unblock_fatal_signals ();
 260       if (exit_on_error || !null_stderr)
 261         error (exit_on_error ? EXIT_FAILURE : 0, err,
 262                _("%s subprocess failed"), progname);
 263       return 127;
 264     }
 265   posix_spawn_file_actions_destroy (&actions);
 266   if (attrs_allocated)
 267     posix_spawnattr_destroy (&attrs);
 268 #else
 269   if (slave_process)
 270     block_fatal_signals ();
 271   /* Use vfork() instead of fork() for efficiency.  */
 272   if ((child = vfork ()) == 0)
 273     {
 274       /* Child process code.  */
 275       int nullinfd;
 276       int nulloutfd;
 277
 278       if ((!null_stdin
 279            || ((nullinfd = open ("/dev/null", O_RDONLY, 0)) >= 0
 280                && (nullinfd == STDIN_FILENO
 281                    || (dup2 (nullinfd, STDIN_FILENO) >= 0
 282                        && close (nullinfd) >= 0))))
 283           && (!(null_stdout || null_stderr)
 284               || ((nulloutfd = open ("/dev/null", O_RDWR, 0)) >= 0
 285                   && (!null_stdout
 286                       || nulloutfd == STDOUT_FILENO
 287                       || dup2 (nulloutfd, STDOUT_FILENO) >= 0)
 288                   && (!null_stderr
 289                       || nulloutfd == STDERR_FILENO
 290                       || dup2 (nulloutfd, STDERR_FILENO) >= 0)
 291                   && ((null_stdout && nulloutfd == STDOUT_FILENO)
 292                       || (null_stderr && nulloutfd == STDERR_FILENO)
 293                       || close (nulloutfd) >= 0)))
 294           && (!slave_process || (unblock_fatal_signals (), true)))
 295         execvp (prog_path, prog_argv);
 296       _exit (127);
 297     }
 298   if (child == -1)
 299     {
 300       if (slave_process)
 301         unblock_fatal_signals ();
 302       if (exit_on_error || !null_stderr)
 303         error (exit_on_error ? EXIT_FAILURE : 0, errno,
 304                _("%s subprocess failed"), progname);
 305       return 127;
 306     }
 307 #endif
 308   if (slave_process)
 309     {
 310       register_slave_subprocess (child);
 311       unblock_fatal_signals ();
 312     }
 313
 314   return wait_subprocess (child, progname, ignore_sigpipe, null_stderr,
 315                           slave_process, exit_on_error);
 316
 317 #endif
 318 }