-/* Creation of subprocesses, communicating via pipes.
- Copyright (C) 2001-2004, 2006-2007 Free Software Foundation, Inc.
- Written by Bruno Haible <haible@clisp.cons.org>, 2001.
+/* Create a pipe.
+ Copyright (C) 2009-2014 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
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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
-
+ You should have received a copy of the GNU General Public License along
+ with this program; if not, see <http://www.gnu.org/licenses/>. */
#include <config.h>
/* Specification. */
-#include "pipe.h"
-
-#include <errno.h>
-#include <fcntl.h>
-#include <stdlib.h>
-#include <signal.h>
#include <unistd.h>
-#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. */
-# if HAVE_POSIX_SPAWN
-# include <spawn.h>
-# else
-# if HAVE_VFORK_H
-# include <vfork.h>
-# endif
-# endif
-
-#endif
-
-#if ! HAVE_ENVIRON_DECL
-extern char **environ;
-#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
-
-/* The results of open() in this file are not used with fchdir,
- therefore save some unnecessary work in fchdir.c. */
-#undef open
-#undef close
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+/* Native Windows API. */
+/* Get _pipe(). */
+# include <io.h>
-#ifdef EINTR
+/* Get _O_BINARY. */
+# include <fcntl.h>
-/* 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
+pipe (int fd[2])
{
- 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)
+ /* Mingw changes fd to {-1,-1} on failure, but this violates
+ http://austingroupbugs.net/view.php?id=467 */
+ int tmp[2];
+ int result = _pipe (tmp, 4096, _O_BINARY);
+ if (!result)
{
- 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;
+ fd[0] = tmp[0];
+ fd[1] = tmp[1];
}
-
- if (pipe_stdout)
- fd[0] = ifd[0];
- if (pipe_stdin)
- fd[1] = ofd[1];
- return child;
+ return result;
+}
#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;
+# error "This platform lacks a pipe function, and Gnulib doesn't provide a replacement. This is a bug in Gnulib."
#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;
-}
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