pidstat: pidstat should return the exit code of the child process (#339)

When a process is monitored with option -e, pidstat should return the
exit code of this process and a default value of 0.

Signed-off-by: Sebastien GODARD <sysstat@users.noreply.github.com>

diff --git a/pidstat.c b/pidstat.c
index 7e302d5070b5c7253a662962563690105163fda0..57469bdbb36cddaf97b3cbc0bf8681a734c87108 100644 (file)
--- a/pidstat.c
+++ b/pidstat.c
@@ -30,6 +30,7 @@
 #include <sys/types.h>
 #include <pwd.h>
 #include <sys/utsname.h>
+#include <sys/wait.h>
 #include <regex.h>
 
 #ifdef HAVE_LINUX_SCHED_H
@@ -73,6 +74,7 @@ unsigned int actflag = 0;     /* Activity flag */
 
 struct sigaction alrm_act, int_act, chld_act;
 int signal_caught = 0;
+int status = 0;
 
 int dplaces_nr = -1;           /* Number of decimal places */
 
@@ -120,7 +122,18 @@ void alarm_handler(int sig)
  */
 void int_handler(int sig)
 {
-       signal_caught = 1;
+       int status_code;
+
+       signal_caught = TRUE;
+
+       if (sig == SIGCHLD) {
+               /*
+                * SIGCHLD tells the parent process that it can now
+                * get the exit status of the child via wait().
+                */
+               wait(&status_code);
+               status = WEXITSTATUS(status_code);
+       }
 }
 
 /*
@@ -2830,5 +2843,9 @@ int main(int argc, char **argv)
        /* Free structures */
        sfree_pid(&pid_list, TRUE);
 
-       return 0;
+       /*
+        * @status contains the exit code of the child process monitored with option -e,
+        * or 0 otherwise.
+        */
+       return status;
 }