Executing programs, without pipe.

4 files changed, 226 insertions, 8 deletions

diff --git a/lib/ChangeLog b/lib/ChangeLog
index 03e041a..06f1f52 100644
--- a/lib/ChangeLog
+++ b/lib/ChangeLog
@@ -1,5 +1,12 @@
 2001-09-02  Bruno Haible  <haible@clisp.cons.org>
 
+	* execute.h: New file.
+	* execute.c: New file.
+	* Makefile.am (libnlsut_a_SOURCES): Add execute.c.
+	(noinst_HEADERS): Add execute.h.
+
+2001-09-02  Bruno Haible  <haible@clisp.cons.org>
+
 	* gcd.h: New file.
 	* gcd.c: New file.
 	* Makefile.am (libnlsut_a_SOURCES): Add gcd.c.
diff --git a/lib/Makefile.am b/lib/Makefile.am
index 488ac0a..0ad1557 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -27,17 +27,17 @@ strncasecmp.c strstr.c strtol.c strtoul.c vasprintf.c \
 stdbool.h.in \
 gen-lbrkprop.c 3level.h
 
-libnlsut_a_SOURCES = basename.c c-ctype.c concatpath.c findprog.c fstrcmp.c \
-full-write.c gcd.c getopt.c getopt1.c hash.c linebreak.c localcharset.c \
-mbswidth.c obstack.c pipe-bidi.c pipe-in.c pipe-out.c progname.c safe-read.c \
-wait-process.c xerror.c xgetcwd.c xmalloc.c xstrdup.c
+libnlsut_a_SOURCES = basename.c c-ctype.c concatpath.c execute.c findprog.c \
+fstrcmp.c full-write.c gcd.c getopt.c getopt1.c hash.c linebreak.c \
+localcharset.c mbswidth.c obstack.c pipe-bidi.c pipe-in.c pipe-out.c \
+progname.c safe-read.c wait-process.c xerror.c xgetcwd.c xmalloc.c xstrdup.c
 
 libnlsut_a_LIBADD = @ALLOCA@ @LIBOBJS@
 
-noinst_HEADERS = c-ctype.h error.h findprog.h fstrcmp.h full-write.h gcd.h \
-getline.h getopt.h hash.h lbrkprop.h linebreak.h mbswidth.h obstack.h \
-pathmax.h pipe.h progname.h safe-read.h system.h utf8-ucs4.h utf16-ucs4.h \
-wait-process.h xerror.h
+noinst_HEADERS = c-ctype.h error.h execute.h findprog.h fstrcmp.h \
+full-write.h gcd.h getline.h getopt.h hash.h lbrkprop.h linebreak.h mbswidth.h \
+obstack.h pathmax.h pipe.h progname.h safe-read.h system.h utf8-ucs4.h \
+utf16-ucs4.h wait-process.h xerror.h
 
 DEFS = -DLIBDIR=\"$(libdir)\" @DEFS@
 INCLUDES = -I. -I$(srcdir) -I.. -I../intl
diff --git a/lib/execute.c b/lib/execute.c
new file mode 100644
index 0000000..48cba72
--- /dev/null
+++ b/lib/execute.c
@@ -0,0 +1,179 @@
+/* Creation of autonomous subprocesses.
+   Copyright (C) 2001 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 "execute.h"
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdbool.h>
+#include <stdlib.h>
+
+#ifdef HAVE_UNISTD_H
+# include <unistd.h>
+#endif
+
+#ifdef HAVE_POSIX_SPAWN
+# include <spawn.h>
+#else
+# ifdef HAVE_VFORK_H
+#  include <vfork.h>
+# endif
+#endif
+
+#include "error.h"
+#include "wait-process.h"
+#include "libgettext.h"
+
+#ifndef STDIN_FILENO
+# define STDIN_FILENO 0
+#endif
+#ifndef STDOUT_FILENO
+# define STDOUT_FILENO 1
+#endif
+#ifndef STDERR_FILENO
+# define STDERR_FILENO 2
+#endif
+
+#define _(str) gettext (str)
+
+
+/* Prototypes for local functions.  Needed to ensure compiler checking of
+   function argument counts despite of K&R C function definition syntax.  */
+#ifdef EINTR
+static inline int nonintr_close PARAMS ((int fd));
+static inline int nonintr_open PARAMS ((const char *pathname, int oflag,
+					mode_t mode));
+#endif
+
+
+#ifdef EINTR
+
+/* EINTR handling for close(), open().
+   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 (fd)
+     int fd;
+{
+  int retval;
+
+  do
+    retval = close (fd);
+  while (retval < 0 && errno == EINTR);
+
+  return retval;
+}
+#define close nonintr_close
+
+static inline int
+nonintr_open (pathname, oflag, mode)
+     const char *pathname;
+     int oflag;
+     mode_t mode;
+{
+  int retval;
+
+  do
+    retval = open (pathname, oflag, mode);
+  while (retval < 0 && errno == EINTR);
+
+  return retval;
+}
+#define open nonintr_open
+
+#endif
+
+
+/* Execute a command, optionally redirecting any of the three standard file
+   descriptors to /dev/null.  Exit if it didn't terminate correctly.
+   Otherwise return its exit code.  */
+int
+execute (progname, prog_path, prog_argv, null_stdin, null_stdout, null_stderr)
+     const char *progname;
+     const char *prog_path;
+     char **prog_argv;
+     bool null_stdin;
+     bool null_stdout;
+     bool null_stderr;
+{
+#if HAVE_POSIX_SPAWN
+  posix_spawn_file_actions_t actions;
+  int err;
+  pid_t child;
+#else
+  int child;
+#endif
+
+#if HAVE_POSIX_SPAWN
+  if ((err = posix_spawn_file_actions_init (&actions)) != 0
+      || (null_stdin
+	  && (err = posix_spawn_file_actions_addopen (&actions, STDIN_FILENO,
+						      "/dev/null", O_RDONLY, 0))
+	     != 0)
+      || (null_stdout
+	  && (err = posix_spawn_file_actions_addopen (&actions, STDOUT_FILENO,
+						      "/dev/null", O_RDWR, 0))
+	     != 0)
+      || (null_stderr
+	  && (err = posix_spawn_file_actions_addopen (&actions, STDERR_FILENO,
+						      "/dev/null", O_RDWR, 0))
+	     != 0)
+      || (err = posix_spawnp (&child, prog_path, &actions, NULL, prog_argv,
+			      environ)) != 0)
+    error (EXIT_FAILURE, err, _("%s subprocess failed"), progname);
+  posix_spawn_file_actions_destroy (&actions);
+#else
+  /* Use vfork() instead of fork() for efficiency.  */
+  if ((child = vfork ()) == 0)
+    {
+      /* Child process code.  */
+      int nullinfd;
+      int nulloutfd;
+
+      if ((!null_stdin
+	   || ((nullinfd = open ("/dev/null", O_RDONLY, 0)) >= 0
+	       && (nullinfd == STDIN_FILENO
+		   || (dup2 (nullinfd, STDIN_FILENO) >= 0
+		       && close (nullinfd) >= 0))))
+	  && (!(null_stdout || null_stderr)
+	      || ((nulloutfd = open ("/dev/null", O_RDWR, 0)) >= 0
+		  && (!null_stdout
+		      || nulloutfd == STDOUT_FILENO
+		      || dup2 (nulloutfd, STDOUT_FILENO) >= 0)
+		  && (!null_stderr
+		      || nulloutfd == STDERR_FILENO
+		      || dup2 (nulloutfd, STDERR_FILENO) >= 0)
+		  && ((null_stdout && nulloutfd == STDOUT_FILENO)
+		      || (null_stderr && nulloutfd == STDERR_FILENO)
+		      || close (nulloutfd) >= 0))))
+	execvp (prog_path, prog_argv);
+      _exit (-1);
+    }
+  if (child == -1)
+    error (EXIT_FAILURE, errno, _("%s subprocess failed"), progname);
+#endif
+
+  return wait_subprocess (child, progname);
+}
diff --git a/lib/execute.h b/lib/execute.h
new file mode 100644
index 0000000..7a2cc49
--- /dev/null
+++ b/lib/execute.h
@@ -0,0 +1,32 @@
+/* Creation of autonomous subprocesses.
+   Copyright (C) 2001 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.  */
+
+#ifndef _EXECUTE_H
+#define _EXECUTE_H
+
+#include <stdbool.h>
+
+/* Execute a command, optionally redirecting any of the three standard file
+   descriptors to /dev/null.  Exit if it didn't terminate correctly.
+   Otherwise return its exit code.  */
+extern int execute PARAMS ((const char *progname,
+			    const char *prog_path, char **prog_argv,
+			    bool null_stdin,
+			    bool null_stdout, bool null_stderr));
+
+#endif /* _EXECUTE_H */