setsid: add an option to wait child return value

This change proposed in util-linux maillist by Damien Wyart in behalf of
Daniel Kahn Gillmor.  Sami Kerola changed the patch to use option rather
than makign the default behavior of the command to change.

Reported-by: Damien Wyart <damien.wyart@gmail.com>
Reference: http://markmail.org/message/2z6qh5auk7wjie3l
Bug-Debian: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=495881
CC: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
Signed-off-by: Sami Kerola <kerolasa@iki.fi>

diff --git a/sys-utils/setsid.1 b/sys-utils/setsid.1
index eff794858164355928b1384d95735e06cd9852b2..da8d648e73129d7614e8264c84211d038780309a 100644 (file)
--- a/sys-utils/setsid.1
+++ b/sys-utils/setsid.1
@@ -15,6 +15,11 @@ runs a program in a new session.
 .TP
 \fB\-c\fP, \fB\-\-ctty\fP
 Set the controlling terminal to the current one.
+.TP
+\fB\-w\fP, \fB\-\-wait\fP
+Wait the execution of the program to end, and return the exit value of
+the child as return value of the
+.BR setsid .
 .SH "SEE ALSO"
 .BR setsid (2)
 .SH AUTHOR

diff --git a/sys-utils/setsid.c b/sys-utils/setsid.c
index 756a520d8d082181f256c9746a5abfc00168a7c2..782de82b5d21caace57efda075e384811d8d1df0 100644 (file)
--- a/sys-utils/setsid.c
+++ b/sys-utils/setsid.c
@@ -9,6 +9,8 @@
  * 2001-01-18 John Fremlin <vii@penguinpowered.com>
  * - fork in case we are process group leader
  *
+ * 2008-08-20 Daniel Kahn Gillmor <dkg@fifthhorseman.net>
+ * - if forked, wait on child process and emit its return code.
  */
 
 #include <getopt.h>
@@ -16,6 +18,8 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <sys/ioctl.h>
+#include <sys/types.h>
+#include <sys/wait.h>
 
 #include "c.h"
 #include "nls.h"
@@ -29,8 +33,8 @@ static void __attribute__ ((__noreturn__)) usage(FILE * out)
                program_invocation_short_name);
 
        fputs(USAGE_OPTIONS, out);
-       fputs(_(" -c, --ctty     set the controlling terminal to the current one\n"),
-               out);
+       fputs(_(" -c, --ctty     set the controlling terminal to the current one\n"), out);
+       fputs(_(" -w, --wait     wait program to exit, and use the same return\n"), out);
 
        fputs(USAGE_HELP, out);
        fputs(USAGE_VERSION, out);
@@ -43,9 +47,12 @@ int main(int argc, char **argv)
 {
        int ch;
        int ctty = 0;
+       pid_t pid;
+       int status = 0;
 
        static const struct option longopts[] = {
                {"ctty", no_argument, NULL, 'c'},
+               {"wait", no_argument, NULL, 'w'},
                {"version", no_argument, NULL, 'V'},
                {"help", no_argument, NULL, 'h'},
                {NULL, 0, NULL, 0}
@@ -56,7 +63,7 @@ int main(int argc, char **argv)
        textdomain(PACKAGE);
        atexit(close_stdout);
 
-       while ((ch = getopt_long(argc, argv, "+Vhc", longopts, NULL)) != -1)
+       while ((ch = getopt_long(argc, argv, "+Vhcw", longopts, NULL)) != -1)
                switch (ch) {
                case 'V':
                        printf(UTIL_LINUX_VERSION);
@@ -64,6 +71,9 @@ int main(int argc, char **argv)
                case 'c':
                        ctty=1;
                        break;
+               case 'w':
+                       status = 1;
+                       break;
                case 'h':
                        usage(stdout);
                default:
@@ -74,7 +84,8 @@ int main(int argc, char **argv)
                usage(stderr);
 
        if (getpgrp() == getpid()) {
-               switch (fork()) {
+               pid = fork();
+               switch (pid) {
                case -1:
                        err(EXIT_FAILURE, _("fork"));
                case 0:
@@ -82,7 +93,13 @@ int main(int argc, char **argv)
                        break;
                default:
                        /* parent */
-                       return 0;
+                       if (!status)
+                               return EXIT_SUCCESS;
+                       if (wait(&status) != pid)
+                               err(EXIT_FAILURE, "wait");
+                       if (WIFEXITED(status))
+                               return WEXITSTATUS(status);
+                       err(status, _("child %d did not exit normally"), pid);
                }
        }
        if (setsid() < 0)