Source Code 1992 March/Source_Code_CD-ROM_Walnut_Creek_March_1992.iso/usenet/altsrcs/1/1242

Internet Message Format | 1990-12-28 | 3.2 KB

From: [e-mail] (Maarten Litmaath)
Newsgroups: comp.unix.wizards,alt.sources
Subject: Re: Trying to kill a daemon at logout time
Message-ID: <[e-mail]>
Date: 26 Apr 90 18:22:31 GMT

In article <[e-mail]>,
    [e-mail] (Edward Vielmetti) writes:
)In article <[e-mail]>
)    [e-mail] (Chris Czerwinski) writes:
)
)
)   I have a program that generates a daemon when I log in. That is easy
)   enough. My problem is that I want it to disappear when I logout.
)
)If your program generates a daemon, then you should have the daemon write
)the pid it's using to a file (ala syslogd or named).  Then you can simply
)do
)    kill -TERM `cat ~chrisc/mydaemon.pid`
)without any risk of whomping the wrong job or having to resort to any
)odd shell invocations.

If you don't like temp files, you can use the following program, which
essentially is the opposite of nohup(1).  Note the close-on-exec trick.

: This is a shar archive.  Extract with sh, not csh.
: This archive ends with exit, so do not worry about trailing junk.
: --------------------------- cut here --------------------------
PATH=/bin:/usr/bin:/usr/ucb
echo Extracting 'hup.c'
sed 's/^X//' > 'hup.c' << '+ END-OF-FILE ''hup.c'
X/*
X * hup.c
X * Run a background job in the process group of its parent (the shell),
X * so that it will receive a SIGHUP on logout.
X * Usage: hup command
X * Note: `hup' will put `command' in the background itself, so there's no
X * need for a trailing `&'.
X * Compile with `-DNO_FCNTL' if your UNIX variant doesn't have fcntl(2).
X * If your shell is csh, you might want to end your `.logout' file with an
X * `exec' command (e.g. `exec true') to get `hup' to work on an `rlogin'.  :-(
X * Author: Maarten Litmaath @ VU Informatika Amsterdam ([e-mail])
X */
X#include    <stdio.h>
X#include    <signal.h>
X#ifdef    NO_FCNTL
X#include    <sys/ioctl.h>
X#else
X#include    <fcntl.h>
X#endif    /* NO_FCNTL */
X
Xchar    Id[] = "@(#)hup 1.0 90/03/09 Maarten Litmaath";
X
Xint    Keyboard_signals[] = {
X    SIGINT,
X    SIGQUIT,
X#ifdef    SIGTSTP
X    SIGTSTP,
X#endif    /* SIGTSTP */
X    0
X};
X
Xmain(argc, argv)
Xint    argc;
Xchar    **argv;
X{
X    int    pgrp, sig, i, pp[2];
X    char    buf[1];
X
X    if (argc == 1) {
X        fprintf(stderr, "Usage: %s command\n", argv[0]);
X        exit(1);
X    }
X
X    pgrp = getpgrp(getppid());
X
X    if (pipe(pp) < 0) {
X        perror("pipe");
X        exit(1);
X    }
X
X    switch (fork()) {
X    case -1:
X        perror("fork");
X        exit(1);
X    case 0:
X        for (i = 0; sig = Keyboard_signals[i]; i++)
X            signal(sig, SIG_IGN);
X
X        if (setpgrp(0, pgrp) < 0) {
X            perror("setpgrp");
X            exit(1);
X        }
X
X        close(pp[0]);
X
X        /* set close-on-exec flag */
X#ifdef    NO_FCNTL
X        ioctl(pp[1], FIOCLEX, (int *) 0);
X#else
X        fcntl(pp[1], F_SETFD, 1);
X#endif    /* NO_FCNTL */
X
X        execvp(argv[1], &argv[1]);
X        perror(argv[1]);
X
X        /* send a message to indicate failure */
X        write(pp[1], buf, 1);
X        exit(1);
X    }
X    close(pp[1]);
X    exit(read(pp[0], buf, 1));
X}
+ END-OF-FILE hup.c
chmod 'u=rw,g=r,o=r' 'hup.c'
set `wc -c 'hup.c'`
count=$1
case $count in
1627)    :;;
*)    echo 'Bad character count in ''hup.c' >&2
        echo 'Count should be 1627' >&2
esac
exit 0
--
 1) Alias must go as well.            |Maarten Litmaath @ VU Amsterdam:
 2) Sleep(3) should be sleep(2) again.|[e-mail], uunet!cs.vu.nl!maart