summaryrefslogtreecommitdiff
path: root/src/nohup.c
diff options
context:
space:
mode:
authorJim Meyering <jim@meyering.net>2003-07-11 20:34:29 +0000
committerJim Meyering <jim@meyering.net>2003-07-11 20:34:29 +0000
commit8db77b89784b5fba5ec5b283eed4bf83ad4f5f28 (patch)
tree65c63d502a58c5c8e80758e0921486759c92dc25 /src/nohup.c
parent9c557c0a2782fa557b5b57a4f4420f0a06ffa125 (diff)
downloadcoreutils-8db77b89784b5fba5ec5b283eed4bf83ad4f5f28.tar.xz
New file. Rewrite of nohup.sh in C.
This solves a portability problem: on at least Solaris systems, when nohup.sh used the vendor /bin/sh, it would exit with status of `1' rather than the required 126 or 127 upon failure to exec the specified program.
Diffstat (limited to 'src/nohup.c')
-rw-r--r--src/nohup.c183
1 files changed, 183 insertions, 0 deletions
diff --git a/src/nohup.c b/src/nohup.c
new file mode 100644
index 000000000..9c7aeff7e
--- /dev/null
+++ b/src/nohup.c
@@ -0,0 +1,183 @@
+/* nohup -- run a command immume to hangups, with output to a non-tty
+ Copyright (C) 2003 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
+ 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. */
+
+/* Written by Jim Meyering */
+
+#include <config.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <signal.h>
+
+#include "system.h"
+
+#include "closeout.h"
+#include "error.h"
+#include "long-options.h"
+#include "path-concat.h"
+#include "quote.h"
+
+#define PROGRAM_NAME "nohup"
+
+#define AUTHORS "Jim Meyering"
+
+char *program_name;
+
+void
+usage (int status)
+{
+ if (status != 0)
+ fprintf (stderr, _("Try `%s --help' for more information.\n"),
+ program_name);
+ else
+ {
+ printf (_("\
+Usage: %s COMMAND [ARG]...\n\
+ or: %s OPTION\n\
+"),
+ program_name, program_name);
+
+ fputs (_("\
+Run COMMAND, ignoring hangup signals.\n\
+\n\
+"), stdout);
+ fputs (HELP_OPTION_DESCRIPTION, stdout);
+ fputs (VERSION_OPTION_DESCRIPTION, stdout);
+ printf (_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
+ }
+ exit (status);
+}
+
+int
+main (int argc, char **argv)
+{
+ int fd;
+ int saved_stderr_fd = -1;
+ int stderr_isatty;
+
+ initialize_main (&argc, &argv);
+ program_name = argv[0];
+ setlocale (LC_ALL, "");
+ bindtextdomain (PACKAGE, LOCALEDIR);
+ textdomain (PACKAGE);
+
+ atexit (close_stdout);
+
+ parse_long_options (argc, argv, PROGRAM_NAME, GNU_PACKAGE, VERSION,
+ AUTHORS, usage);
+
+ /* The above handles --help and --version.
+ Now, handle `--'. */
+ if (argc > 1 && STREQ (argv[1], "--"))
+ {
+ --argc;
+ ++argv;
+ }
+
+ if (argc <= 1)
+ {
+ error (0, 0, _("too few arguments"));
+ usage (EXIT_FAILURE);
+ }
+
+ /* If standard output is a tty, redirect it (appending) to a file.
+ First try nohup.out, then $HOME/nohup.out. */
+ if (isatty (STDOUT_FILENO))
+ {
+ char *in_home = NULL;
+ char const *file = "nohup.out";
+ int flags = O_CREAT | O_WRONLY | O_APPEND;
+ mode_t mode = S_IRUSR | S_IWUSR;
+ int saved_errno;
+
+ fd = open (file, flags, mode);
+ if (fd == -1)
+ {
+ saved_errno = errno;
+ in_home = path_concat (getenv ("HOME"), file, NULL);
+ fd = open (in_home, flags, mode);
+ if (fd == -1)
+ {
+ int saved_errno2 = errno;
+ error (0, saved_errno, _("failed to open %s"), quote (file));
+ error (0, saved_errno2, _("failed to open %s"), quote (in_home));
+ exit (EXIT_FAILURE);
+ }
+ file = in_home;
+ }
+
+ /* Redirect standard output to the file. */
+ if (dup2 (fd, STDOUT_FILENO) == -1)
+ error (EXIT_FAILURE, errno, _("failed to redirect standard output"));
+
+ error (0, 0, _("appending output to %s"), quote (file));
+ if (in_home)
+ free (in_home);
+ }
+ else
+ {
+ fd = STDOUT_FILENO;
+ }
+
+ /* If stderr is on a tty, redirect it to stdout. */
+ if ((stderr_isatty = isatty (STDERR_FILENO)))
+ {
+ /* Save a copy of stderr before redirecting, so we can use the original
+ if execve fails. It's no big deal if this dup fails. It might
+ not change anything, and at worst, it'll lead to suppression of
+ the post-failed-execve diagnostic. */
+ saved_stderr_fd = dup (STDERR_FILENO);
+
+ if (dup2 (fd, STDERR_FILENO) == -1)
+ error (EXIT_FAILURE, errno, _("failed to redirect standard error"));
+ }
+
+ /* Ignore hang-up signals. */
+ {
+#ifdef _POSIX_SOURCE
+ struct sigaction sigact;
+ sigact.sa_handler = SIG_IGN;
+ sigemptyset (&sigact.sa_mask);
+ sigact.sa_flags = 0;
+ sigaction (SIGHUP, &sigact, NULL);
+#else
+ signal (SIGHUP, SIG_IGN);
+#endif
+ }
+
+ {
+ int exit_status;
+ int saved_errno;
+ char **cmd = argv + 1;
+
+ execvp (*cmd, cmd);
+ exit_status = (errno == ENOENT ? 127 : 126);
+ saved_errno = errno;
+
+ /* The execve failed. Output a diagnostic to stderr only if:
+ - stderr was initially redirected to a non-tty, or
+ - stderr was initially directed to a tty, and we've
+ just dup2'd it to point back to that same tty.
+ In other words, output the diagnostic if possible, but not if
+ it'd go to nohup.out. */
+ if ( ! stderr_isatty
+ || (saved_stderr_fd != -1
+ && dup2 (saved_stderr_fd, STDERR_FILENO) != -1))
+ error (0, saved_errno, _("cannot run command %s"), quote (*cmd));
+
+ exit (exit_status);
+ }
+}