#include <unistd.h>
#include <sys/types.h>
#include <signal.h>
-#include <sys/wait.h>
#include <stdio.h>
#include <fcntl.h>
#include <string.h>
/*
* Start a child-process with the specified command and reroute stdin.
* We actually start a $SHELL to execute the command so we don't have to care
- * about arguments and such.
- * We also double-fork() to avoid zombies and pass the pid of the child through a
- * temporary pipe back to i3bar
+ * about arguments and such
*
*/
void start_child(char *command) {
child_pid = 0;
if (command != NULL) {
- int fd[2], tmp[2];
- /* This pipe will be used to communicate between e.g. i3status and i3bar */
+ int fd[2];
pipe(fd);
- /* We also need this temporary pipe to get back the pid of i3status */
- pipe(tmp);
- switch (fork()) {
+ child_pid = fork();
+ switch (child_pid) {
case -1:
ELOG("Couldn't fork()\n");
exit(EXIT_FAILURE);
case 0:
- /* Double-fork(), so the child gets reparented to init */
- switch(child_pid = fork()) {
- case -1:
- ELOG("Couldn't fork() twice\n");
- exit(EXIT_FAILURE);
- case 0:
- /* Child-process. Reroute stdout and start shell */
- close(fd[0]);
-
- dup2(fd[1], STDOUT_FILENO);
-
- static const char *shell = NULL;
-
- if ((shell = getenv("SHELL")) == NULL)
- shell = "/bin/sh";
-
- execl(shell, shell, "-c", command, (char*) NULL);
- return;
- default:
- /* Temporary parent. We tell i3bar about the pid of i3status and exit */
- write(tmp[1], &child_pid, sizeof(int));
- close(tmp[0]);
- close(tmp[1]);
- exit(EXIT_SUCCESS);
- }
+ /* Child-process. Reroute stdout and start shell */
+ close(fd[0]);
+
+ dup2(fd[1], STDOUT_FILENO);
+
+ static const char *shell = NULL;
+
+ if ((shell = getenv("SHELL")) == NULL)
+ shell = "/bin/sh";
+
+ execl(shell, shell, "-c", command, (char*) NULL);
+ return;
default:
/* Parent-process. Rerout stdin */
close(fd[1]);
dup2(fd[0], STDIN_FILENO);
- /* We also need to get the pid of i3status from the temporary pipe */
- size_t rec = 0;
- while (rec < sizeof(int)) {
- rec += read(tmp[0], &child_pid, sizeof(int) - rec);
- }
- /* The temporary pipe is no longer needed */
- close(tmp[0]);
- close(tmp[1]);
break;
}
}
- wait(0);
/* We set O_NONBLOCK because blocking is evil in event-driven software */
fcntl(STDIN_FILENO, F_SETFL, O_NONBLOCK);