]> git.ipfire.org Git - thirdparty/gettext.git/commitdiff
Pipe creation primitives.
authorBruno Haible <bruno@clisp.org>
Tue, 3 Feb 2004 12:59:58 +0000 (12:59 +0000)
committerBruno Haible <bruno@clisp.org>
Tue, 23 Jun 2009 10:11:47 +0000 (12:11 +0200)
gettext-tools/lib/pipe.c [new file with mode: 0644]

diff --git a/gettext-tools/lib/pipe.c b/gettext-tools/lib/pipe.c
new file mode 100644 (file)
index 0000000..36d7ad0
--- /dev/null
@@ -0,0 +1,506 @@
+/* Creation of subprocesses, communicating via pipes.
+   Copyright (C) 2001-2004 Free Software Foundation, Inc.
+   Written by Bruno Haible <haible@clisp.cons.org>, 2001.
+
+   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 version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   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.  */
+
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+/* Specification.  */
+#include "pipe.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <signal.h>
+
+#ifdef HAVE_UNISTD_H
+# include <unistd.h>
+#endif
+
+#include "error.h"
+#include "exit.h"
+#include "fatal-signal.h"
+#include "wait-process.h"
+#include "gettext.h"
+
+#define _(str) gettext (str)
+
+#if defined _MSC_VER || defined __MINGW32__
+
+/* Native Woe32 API.  */
+# include <process.h>
+# include "w32spawn.h"
+
+#else
+
+/* Unix API.  */
+# ifdef HAVE_POSIX_SPAWN
+#  include <spawn.h>
+# else
+#  ifdef HAVE_VFORK_H
+#   include <vfork.h>
+#  endif
+# endif
+
+#endif
+
+#ifndef STDIN_FILENO
+# define STDIN_FILENO 0
+#endif
+#ifndef STDOUT_FILENO
+# define STDOUT_FILENO 1
+#endif
+#ifndef STDERR_FILENO
+# define STDERR_FILENO 2
+#endif
+
+
+#ifdef EINTR
+
+/* EINTR handling for close().
+   These functions can return -1/EINTR even though we don't have any
+   signal handlers set up, namely when we get interrupted via SIGSTOP.  */
+
+static inline int
+nonintr_close (int fd)
+{
+  int retval;
+
+  do
+    retval = close (fd);
+  while (retval < 0 && errno == EINTR);
+
+  return retval;
+}
+#define close nonintr_close
+
+static inline int
+nonintr_open (const char *pathname, int oflag, mode_t mode)
+{
+  int retval;
+
+  do
+    retval = open (pathname, oflag, mode);
+  while (retval < 0 && errno == EINTR);
+
+  return retval;
+}
+#undef open /* avoid warning on VMS */
+#define open nonintr_open
+
+#endif
+
+
+/* Open a pipe connected to a child process.
+ *
+ *           write       system                read
+ *    parent  ->   fd[1]   ->   STDIN_FILENO    ->   child       if pipe_stdin
+ *    parent  <-   fd[0]   <-   STDOUT_FILENO   <-   child       if pipe_stdout
+ *           read        system                write
+ *
+ * At least one of pipe_stdin, pipe_stdout must be true.
+ * pipe_stdin and prog_stdin together determine the child's standard input.
+ * pipe_stdout and prog_stdout together determine the child's standard output.
+ * If pipe_stdin is true, prog_stdin is ignored.
+ * If pipe_stdout is true, prog_stdout is ignored.
+ */
+static pid_t
+create_pipe (const char *progname,
+            const char *prog_path, char **prog_argv,
+            bool pipe_stdin, bool pipe_stdout,
+            const char *prog_stdin, const char *prog_stdout,
+            bool null_stderr,
+            bool slave_process, bool exit_on_error,
+            int fd[2])
+{
+#if defined _MSC_VER || defined __MINGW32__
+
+  /* Native Woe32 API.
+     This uses _pipe(), dup2(), and spawnv().  It could also be implemented
+     using the low-level functions CreatePipe(), DuplicateHandle(),
+     CreateProcess() and _open_osfhandle(); see the GNU make and GNU clisp
+     and cvs source code.  */
+  int ifd[2];
+  int ofd[2];
+  int orig_stdin;
+  int orig_stdout;
+  int orig_stderr;
+  int child;
+  int nulloutfd;
+  int stdinfd;
+  int stdoutfd;
+
+  prog_argv = prepare_spawn (prog_argv);
+
+  if (pipe_stdout)
+    if (_pipe (ifd, 4096, O_BINARY | O_NOINHERIT) < 0)
+      error (EXIT_FAILURE, errno, _("cannot create pipe"));
+  if (pipe_stdin)
+    if (_pipe (ofd, 4096, O_BINARY | O_NOINHERIT) < 0)
+      error (EXIT_FAILURE, errno, _("cannot create pipe"));
+/* Data flow diagram:
+ *
+ *           write        system         read
+ *    parent  ->   ofd[1]   ->   ofd[0]   ->   child       if pipe_stdin
+ *    parent  <-   ifd[0]   <-   ifd[1]   <-   child       if pipe_stdout
+ *           read         system         write
+ *
+ */
+
+  /* Save standard file handles of parent process.  */
+  if (pipe_stdin || prog_stdin != NULL)
+    orig_stdin = dup_noinherit (STDIN_FILENO);
+  if (pipe_stdout || prog_stdout != NULL)
+    orig_stdout = dup_noinherit (STDOUT_FILENO);
+  if (null_stderr)
+    orig_stderr = dup_noinherit (STDERR_FILENO);
+  child = -1;
+
+  /* Create standard file handles of child process.  */
+  nulloutfd = -1;
+  stdinfd = -1;
+  stdoutfd = -1;
+  if ((!pipe_stdin || dup2 (ofd[0], STDIN_FILENO) >= 0)
+      && (!pipe_stdout || dup2 (ifd[1], STDOUT_FILENO) >= 0)
+      && (!null_stderr
+         || ((nulloutfd = open ("NUL", O_RDWR, 0)) >= 0
+             && (nulloutfd == STDERR_FILENO
+                 || (dup2 (nulloutfd, STDERR_FILENO) >= 0
+                     && close (nulloutfd) >= 0))))
+      && (pipe_stdin
+         || prog_stdin == NULL
+         || ((stdinfd = open (prog_stdin, O_RDONLY, 0)) >= 0
+             && (stdinfd == STDIN_FILENO
+                 || (dup2 (stdinfd, STDIN_FILENO) >= 0
+                     && close (stdinfd) >= 0))))
+      && (pipe_stdout
+         || prog_stdout == NULL
+         || ((stdoutfd = open (prog_stdout, O_WRONLY, 0)) >= 0
+             && (stdoutfd == STDOUT_FILENO
+                 || (dup2 (stdoutfd, STDOUT_FILENO) >= 0
+                     && close (stdoutfd) >= 0)))))
+    /* The child process doesn't inherit ifd[0], ifd[1], ofd[0], ofd[1],
+       but it inherits all open()ed or dup2()ed file handles (which is what
+       we want in the case of STD*_FILENO) and also orig_stdin,
+       orig_stdout, orig_stderr (which is not explicitly wanted but
+       harmless).  */
+    child = spawnvp (P_NOWAIT, prog_path, prog_argv);
+  if (stdinfd >= 0)
+    close (stdinfd);
+  if (stdoutfd >= 0)
+    close (stdoutfd);
+  if (nulloutfd >= 0)
+    close (nulloutfd);
+
+  /* Restore standard file handles of parent process.  */
+  if (null_stderr)
+    dup2 (orig_stderr, STDERR_FILENO), close (orig_stderr);
+  if (pipe_stdout || prog_stdout != NULL)
+    dup2 (orig_stdout, STDOUT_FILENO), close (orig_stdout);
+  if (pipe_stdin || prog_stdin != NULL)
+    dup2 (orig_stdin, STDIN_FILENO), close (orig_stdin);
+
+  if (pipe_stdin)
+    close (ofd[0]);
+  if (pipe_stdout)
+    close (ifd[1]);
+  if (child == -1)
+    {
+      if (exit_on_error || !null_stderr)
+       error (exit_on_error ? EXIT_FAILURE : 0, errno,
+              _("%s subprocess failed"), progname);
+      if (pipe_stdout)
+       close (ifd[0]);
+      if (pipe_stdin)
+       close (ofd[1]);
+      return -1;
+    }
+
+  if (pipe_stdout)
+    fd[0] = ifd[0];
+  if (pipe_stdin)
+    fd[1] = ofd[1];
+  return child;
+
+#else
+
+  /* Unix API.  */
+  int ifd[2];
+  int ofd[2];
+# if HAVE_POSIX_SPAWN
+  sigset_t blocked_signals;
+  posix_spawn_file_actions_t actions;
+  bool actions_allocated;
+  posix_spawnattr_t attrs;
+  bool attrs_allocated;
+  int err;
+  pid_t child;
+# else
+  int child;
+# endif
+
+  if (pipe_stdout)
+    if (pipe (ifd) < 0)
+      error (EXIT_FAILURE, errno, _("cannot create pipe"));
+  if (pipe_stdin)
+    if (pipe (ofd) < 0)
+      error (EXIT_FAILURE, errno, _("cannot create pipe"));
+/* Data flow diagram:
+ *
+ *           write        system         read
+ *    parent  ->   ofd[1]   ->   ofd[0]   ->   child       if pipe_stdin
+ *    parent  <-   ifd[0]   <-   ifd[1]   <-   child       if pipe_stdout
+ *           read         system         write
+ *
+ */
+
+# if HAVE_POSIX_SPAWN
+  if (slave_process)
+    {
+      sigprocmask (SIG_SETMASK, NULL, &blocked_signals);
+      block_fatal_signals ();
+    }
+  actions_allocated = false;
+  attrs_allocated = false;
+  if ((err = posix_spawn_file_actions_init (&actions)) != 0
+      || (actions_allocated = true,
+         (pipe_stdin
+          && (err = posix_spawn_file_actions_adddup2 (&actions,
+                                                      ofd[0], STDIN_FILENO))
+             != 0)
+         || (pipe_stdout
+             && (err = posix_spawn_file_actions_adddup2 (&actions,
+                                                         ifd[1], STDOUT_FILENO))
+                != 0)
+         || (pipe_stdin
+             && (err = posix_spawn_file_actions_addclose (&actions, ofd[0]))
+                != 0)
+         || (pipe_stdout
+             && (err = posix_spawn_file_actions_addclose (&actions, ifd[1]))
+                != 0)
+         || (pipe_stdin
+             && (err = posix_spawn_file_actions_addclose (&actions, ofd[1]))
+                != 0)
+         || (pipe_stdout
+             && (err = posix_spawn_file_actions_addclose (&actions, ifd[0]))
+                != 0)
+         || (null_stderr
+             && (err = posix_spawn_file_actions_addopen (&actions,
+                                                         STDERR_FILENO,
+                                                         "/dev/null", O_RDWR,
+                                                         0))
+                != 0)
+         || (!pipe_stdin
+             && prog_stdin != NULL
+             && (err = posix_spawn_file_actions_addopen (&actions,
+                                                         STDIN_FILENO,
+                                                         prog_stdin, O_RDONLY,
+                                                         0))
+                != 0)
+         || (!pipe_stdout
+             && prog_stdout != NULL
+             && (err = posix_spawn_file_actions_addopen (&actions,
+                                                         STDOUT_FILENO,
+                                                         prog_stdout, O_WRONLY,
+                                                         0))
+                != 0)
+         || (slave_process
+             && ((err = posix_spawnattr_init (&attrs)) != 0
+                 || (attrs_allocated = true,
+                     (err = posix_spawnattr_setsigmask (&attrs,
+                                                        &blocked_signals))
+                     != 0
+                     || (err = posix_spawnattr_setflags (&attrs,
+                                                       POSIX_SPAWN_SETSIGMASK))
+                        != 0)))
+         || (err = posix_spawnp (&child, prog_path, &actions,
+                                 attrs_allocated ? &attrs : NULL, prog_argv,
+                                 environ))
+            != 0))
+    {
+      if (actions_allocated)
+       posix_spawn_file_actions_destroy (&actions);
+      if (attrs_allocated)
+       posix_spawnattr_destroy (&attrs);
+      if (slave_process)
+       unblock_fatal_signals ();
+      if (exit_on_error || !null_stderr)
+       error (exit_on_error ? EXIT_FAILURE : 0, err,
+              _("%s subprocess failed"), progname);
+      if (pipe_stdout)
+       {
+         close (ifd[0]);
+         close (ifd[1]);
+       }
+      if (pipe_stdin)
+       {
+         close (ofd[0]);
+         close (ofd[1]);
+       }
+      return -1;
+    }
+  posix_spawn_file_actions_destroy (&actions);
+  if (attrs_allocated)
+    posix_spawnattr_destroy (&attrs);
+# else
+  if (slave_process)
+    block_fatal_signals ();
+  /* Use vfork() instead of fork() for efficiency.  */
+  if ((child = vfork ()) == 0)
+    {
+      /* Child process code.  */
+      int nulloutfd;
+      int stdinfd;
+      int stdoutfd;
+
+      if ((!pipe_stdin || dup2 (ofd[0], STDIN_FILENO) >= 0)
+         && (!pipe_stdout || dup2 (ifd[1], STDOUT_FILENO) >= 0)
+         && (!pipe_stdin || close (ofd[0]) >= 0)
+         && (!pipe_stdout || close (ifd[1]) >= 0)
+         && (!pipe_stdin || close (ofd[1]) >= 0)
+         && (!pipe_stdout || close (ifd[0]) >= 0)
+         && (!null_stderr
+             || ((nulloutfd = open ("/dev/null", O_RDWR, 0)) >= 0
+                 && (nulloutfd == STDERR_FILENO
+                     || (dup2 (nulloutfd, STDERR_FILENO) >= 0
+                         && close (nulloutfd) >= 0))))
+         && (pipe_stdin
+             || prog_stdin == NULL
+             || ((stdinfd = open (prog_stdin, O_RDONLY, 0)) >= 0
+                 && (stdinfd == STDIN_FILENO
+                     || (dup2 (stdinfd, STDIN_FILENO) >= 0
+                         && close (stdinfd) >= 0))))
+         && (pipe_stdout
+             || prog_stdout == NULL
+             || ((stdoutfd = open (prog_stdout, O_WRONLY, 0)) >= 0
+                 && (stdoutfd == STDOUT_FILENO
+                     || (dup2 (stdoutfd, STDOUT_FILENO) >= 0
+                         && close (stdoutfd) >= 0))))
+         && (!slave_process || (unblock_fatal_signals (), true)))
+       execvp (prog_path, prog_argv);
+      _exit (127);
+    }
+  if (child == -1)
+    {
+      if (slave_process)
+       unblock_fatal_signals ();
+      if (exit_on_error || !null_stderr)
+       error (exit_on_error ? EXIT_FAILURE : 0, errno,
+              _("%s subprocess failed"), progname);
+      if (pipe_stdout)
+       {
+         close (ifd[0]);
+         close (ifd[1]);
+       }
+      if (pipe_stdin)
+       {
+         close (ofd[0]);
+         close (ofd[1]);
+       }
+      return -1;
+    }
+# endif
+  if (slave_process)
+    {
+      register_slave_subprocess (child);
+      unblock_fatal_signals ();
+    }
+  if (pipe_stdin)
+    close (ofd[0]);
+  if (pipe_stdout)
+    close (ifd[1]);
+
+  if (pipe_stdout)
+    fd[0] = ifd[0];
+  if (pipe_stdin)
+    fd[1] = ofd[1];
+  return child;
+
+#endif
+}
+
+/* Open a bidirectional pipe.
+ *
+ *           write       system                read
+ *    parent  ->   fd[1]   ->   STDIN_FILENO    ->   child
+ *    parent  <-   fd[0]   <-   STDOUT_FILENO   <-   child
+ *           read        system                write
+ *
+ */
+pid_t
+create_pipe_bidi (const char *progname,
+                 const char *prog_path, char **prog_argv,
+                 bool null_stderr,
+                 bool slave_process, bool exit_on_error,
+                 int fd[2])
+{
+  pid_t result = create_pipe (progname, prog_path, prog_argv,
+                             true, true, NULL, NULL,
+                             null_stderr, slave_process, exit_on_error,
+                             fd);
+  return result;
+}
+
+/* Open a pipe for input from a child process.
+ * The child's stdin comes from a file.
+ *
+ *           read        system                write
+ *    parent  <-   fd[0]   <-   STDOUT_FILENO   <-   child
+ *
+ */
+pid_t
+create_pipe_in (const char *progname,
+               const char *prog_path, char **prog_argv,
+               const char *prog_stdin, bool null_stderr,
+               bool slave_process, bool exit_on_error,
+               int fd[1])
+{
+  int iofd[2];
+  pid_t result = create_pipe (progname, prog_path, prog_argv,
+                             false, true, prog_stdin, NULL,
+                             null_stderr, slave_process, exit_on_error,
+                             iofd);
+  if (result != -1)
+    fd[0] = iofd[0];
+  return result;
+}
+
+/* Open a pipe for output to a child process.
+ * The child's stdout goes to a file.
+ *
+ *           write       system                read
+ *    parent  ->   fd[0]   ->   STDIN_FILENO    ->   child
+ *
+ */
+pid_t
+create_pipe_out (const char *progname,
+                const char *prog_path, char **prog_argv,
+                const char *prog_stdout, bool null_stderr,
+                bool slave_process, bool exit_on_error,
+                int fd[1])
+{
+  int iofd[2];
+  pid_t result = create_pipe (progname, prog_path, prog_argv,
+                             true, false, NULL, prog_stdout,
+                             null_stderr, slave_process, exit_on_error,
+                             iofd);
+  if (result != -1)
+    fd[0] = iofd[1];
+  return result;
+}