source: MondoRescue/branches/2.2.5/mindi-busybox/libbb/pidfile.c@ 1765

/* vi: set sw=4 ts=4: */
/*
 * pid file routines
 *
 * Copyright (C) 2007 by Stephane Billiart <stephane.billiart@gmail.com>
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */

/* Override ENABLE_FEATURE_PIDFILE */
#define WANT_PIDFILE 1
#include "libbb.h"

smallint wrote_pidfile;

void write_pidfile(const char *path)
{
    int pid_fd;
    char *end;
    char buf[sizeof(int)*3 + 2];
    struct stat sb;

    if (!path)
        return;
    /* we will overwrite stale pidfile */
    pid_fd = open(path, O_WRONLY|O_CREAT|O_TRUNC, 0666);
    if (pid_fd < 0)
        return;

    /* path can be "/dev/null"! Test for such cases */
    wrote_pidfile = (fstat(pid_fd, &sb) == 0) && S_ISREG(sb.st_mode);

    if (wrote_pidfile) {
        /* few bytes larger, but doesn't use stdio */
        end = utoa_to_buf(getpid(), buf, sizeof(buf));
        *end = '\n';
        full_write(pid_fd, buf, end - buf + 1);
    }
    close(pid_fd);
}