Re: waitpid() with WUNTRACED flag? (was Re: Hang on ctrl+Z after the MPSAFE tsleep/wakeup commit)

[YONETANI Tomokazu]

On Tue, Dec 27, 2005 at 09:15:54AM +0900, YONETANI Tomokazu wrote:
> By the way, here's the code I forgot attaching in the previous message.
*blush*

#include <sys/types.h>
#include <sys/wait.h>
#include <err.h>
#include <errno.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

int
main()
{
        const char *editor = "/usr/bin/vi";
        const char *name;
        pid_t pid, caught;
        int sig;
        int st;

        if (getenv("EDITOR") != NULL)
                editor = getenv("EDITOR");
        if ((name = strrchr(editor, '/')) != NULL)
                ++name;
        else
                name = editor;
        if ((pid = fork()) < 0)
                err(1, "fork");
        if (pid == 0)
                return execlp(editor, name, NULL);
#if 0
        sleep(1);
        killpg(getpgrp(), SIGSTOP);
#endif
        for (;;) {
                caught = waitpid(pid, &st, WUNTRACED);
                warnx("waitpid returned %d\n", caught);
                errno = WEXITSTATUS(st);
                if (caught == -1)
                        return 1;
                else if (WIFSTOPPED(st)) {
                        sig = WSTOPSIG(st);
                        warnx("WSTOPSIG(%d) = %d\n", st, sig);
                        sig = SIGSTOP;
                        raise(sig);
                        warnx("after raise(%d)\n", sig);
                }
                else if (WIFEXITED(st))
                        return errno;
                else
                        return 1;
        }
        return 0;
}