source: MondoRescue/branches/2.2.5/mindi-busybox/coreutils/nohup.c@ 1765

/* vi: set sw=4 ts=4: */
/* nohup - invoke a utility immune to hangups.
 *
 * Busybox version based on nohup specification at
 * http://www.opengroup.org/onlinepubs/007904975/utilities/nohup.html
 *
 * Copyright 2006 Rob Landley <rob@landley.net>
 * Copyright 2006 Bernhard Fischer
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */

#include "libbb.h"

int nohup_main(int argc, char **argv);
int nohup_main(int argc, char **argv)
{
    int nullfd;
    const char *nohupout;
    char *home = NULL;

    xfunc_error_retval = 127;

    if (argc < 2) bb_show_usage();

    nullfd = xopen(bb_dev_null, O_WRONLY|O_APPEND);
    /* If stdin is a tty, detach from it. */
    if (isatty(STDIN_FILENO))
        dup2(nullfd, STDIN_FILENO);

    nohupout = "nohup.out";
    /* Redirect stdout to nohup.out, either in "." or in "$HOME". */
    if (isatty(STDOUT_FILENO)) {
        close(STDOUT_FILENO);
        if (open(nohupout, O_CREAT|O_WRONLY|O_APPEND, S_IRUSR|S_IWUSR) < 0) {
            home = getenv("HOME");
            if (home) {
                nohupout = concat_path_file(home, nohupout);
                xopen3(nohupout, O_CREAT|O_WRONLY|O_APPEND, S_IRUSR|S_IWUSR);
            }
        }
    } else dup2(nullfd, STDOUT_FILENO);

    /* If we have a tty on stderr, announce filename and redirect to stdout.
     * Else redirect to /dev/null.
     */
    if (isatty(STDERR_FILENO)) {
        bb_error_msg("appending to %s", nohupout);
        dup2(STDOUT_FILENO, STDERR_FILENO);
    } else dup2(nullfd, STDERR_FILENO);

    if (nullfd > 2)
        close(nullfd);
    signal(SIGHUP, SIG_IGN);

    BB_EXECVP(argv[1], argv+1);
    if (ENABLE_FEATURE_CLEAN_UP && home)
        free((char*)nohupout);
    bb_perror_msg_and_die("%s", argv[1]);
}