1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
45 	pid_t	pid;  member
51 	pid_t	pid;  member
100 	pid_t pid;  in Popen()  local
114 		fd1 = -1;  in Popen()
117 	pid = start_command(value("SHELL"), &nset, fd0, fd1, "-c", cmd, NULL);  in Popen()
118 	if (pid < 0) {  in Popen()
125 		register_file(fp, 1, pid);  in Popen()
152 		if (fp_head->pipe)  in close_all_files()
153 			(void)Pclose(fp_head->fp);  in close_all_files()
155 			(void)Fclose(fp_head->fp);  in close_all_files()
159 register_file(FILE *fp, int pipe, pid_t pid)  in register_file()  argument
165 	fpp->fp = fp;  in register_file()
166 	fpp->pipe = pipe;  in register_file()
167 	fpp->pid = pid;  in register_file()
168 	fpp->link = fp_head;  in register_file()
177 	for (pp = &fp_head; (p = *pp) != NULL; pp = &p->link)  in unregister_file()
178 		if (p->fp == fp) {  in unregister_file()
179 			*pp = p->link;  in unregister_file()
192 	for (p = fp_head; p != NULL; p = p->link)  in file_pid()
193 		if (p->fp == fp)  in file_pid()
194 			return (p->pid);  in file_pid()
201  * of stdin (-1 means none) and stdout.  The command name can be a sequence
210 	pid_t pid;  in start_commandv()  local
212 	if ((pid = fork()) < 0) {  in start_commandv()
214 		return (-1);  in start_commandv()
216 	if (pid == 0) {  in start_commandv()
228 	return (pid);  in start_commandv()
234 	pid_t pid;  in run_command()  local
238 	pid = start_commandv(cmd, nset, infd, outfd, args);  in run_command()
240 	if (pid < 0)  in run_command()
241 		return -1;  in run_command()
242 	return wait_command(pid);  in run_command()
265 	 * close-on-exec.  in prepare_child()
281 wait_command(pid_t pid)  in wait_command()  argument
284 	if (wait_child(pid) < 0) {  in wait_command()
286 		return (-1);  in wait_command()
292 findchild(pid_t pid, int dont_alloc)  in findchild()  argument
296 	for (cpp = &child; *cpp != NULL && (*cpp)->pid != pid;  in findchild()
297 	    cpp = &(*cpp)->link)  in findchild()
304 			child_freelist = (*cpp)->link;  in findchild()
310 		(*cpp)->pid = pid;  in findchild()
311 		(*cpp)->done = (*cpp)->free = 0;  in findchild()
312 		(*cpp)->link = NULL;  in findchild()
322 	for (cpp = &child; *cpp != cp; cpp = &(*cpp)->link)  in delchild()
324 	*cpp = cp->link;  in delchild()
325 	cp->link = child_freelist;  in delchild()
333 	pid_t pid;  in sigchild()  local
339 	while ((pid = waitpid(-1, &status, WNOHANG)) > 0) {  in sigchild()
340 		cp = findchild(pid, 1);  in sigchild()
343 		if (cp->free)  in sigchild()
346 			cp->done = 1;  in sigchild()
347 			cp->status = status;  in sigchild()
359 wait_child(pid_t pid)  in wait_child()  argument
369 	 * If we have not already waited on the pid (via sigchild)  in wait_child()
373 	cp = findchild(pid, 1);  in wait_child()
374 	if (cp == NULL || !cp->done)  in wait_child()
375 		rv = waitpid(pid, &wait_status, 0);  in wait_child()
377 		wait_status = cp->status;  in wait_child()
381 	if (rv == -1 || (WIFEXITED(wait_status) && WEXITSTATUS(wait_status)))  in wait_child()
382 		return -1;  in wait_child()
391 free_child(pid_t pid)  in free_child()  argument
399 	if ((cp = findchild(pid, 0)) != NULL) {  in free_child()
400 		if (cp->done)  in free_child()
403 			cp->free = 1;  in free_child()