source: MondoRescue/branches/2.2.5/mindi-busybox/procps/kill.c@ 1765

/* vi: set sw=4 ts=4: */
/*
 * Mini kill/killall[5] implementation for busybox
 *
 * Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>.
 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
 *
 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
 */

#include "libbb.h"

/* Note: kill_main is directly called from shell in order to implement
 * kill built-in. Shell substitutes job ids with process groups first.
 *
 * This brings some complications:
 *
 * + we can't use xfunc here
 * + we can't use applet_name
 * + we can't use bb_show_usage
 * (Above doesn't apply for killall[5] cases)
 *
 * kill %n gets translated into kill ' -<process group>' by shell (note space!)
 * This is needed to avoid collision with kill -9 ... syntax
 */

int kill_main(int argc, char **argv);
int kill_main(int argc, char **argv)
{
    char *arg;
    pid_t pid;
    int signo = SIGTERM, errors = 0, quiet = 0;
#if !ENABLE_KILLALL && !ENABLE_KILLALL5
#define killall 0
#define killall5 0
#else
/* How to determine who we are? find 3rd char from the end:
 * kill, killall, killall5
 *  ^i       ^a        ^l  - it's unique
 * (checking from the start is complicated by /bin/kill... case) */
    const char char3 = argv[0][strlen(argv[0]) - 3];
#define killall (ENABLE_KILLALL && char3 == 'a')
#define killall5 (ENABLE_KILLALL5 && char3 == 'l')
#endif

    /* Parse any options */
    argc--;
    arg = *++argv;

    if (argc < 1 || arg[0] != '-') {
        goto do_it_now;
    }

    /* The -l option, which prints out signal names.
     * Intended usage in shell:
     * echo "Died of SIG`kill -l $?`"
     * We try to mimic what kill from coreutils-6.8 does */
    if (arg[1] == 'l' && arg[2] == '\0') {
        if (argc == 1) {
            /* Print the whole signal list */
            for (signo = 1; signo < 32; signo++) {
                const char *name = get_signame(signo);
                if (!isdigit(name[0]))
                    puts(name);
            }
        } else { /* -l <sig list> */
            while ((arg = *++argv)) {
                if (isdigit(arg[0])) {
                    signo = bb_strtou(arg, NULL, 10);
                    if (errno) {
                        bb_error_msg("unknown signal '%s'", arg);
                        return EXIT_FAILURE;
                    }
                    /* Exitcodes >= 0x80 are to be treated
                     * as "killed by signal (exitcode & 0x7f)" */
                    puts(get_signame(signo & 0x7f));
                    /* TODO: 'bad' signal# - coreutils says:
                     * kill: 127: invalid signal
                     * we just print "127" instead */
                } else {
                    signo = get_signum(arg);
                    if (signo < 0) {
                        bb_error_msg("unknown signal '%s'", arg);
                        return EXIT_FAILURE;
                    }
                    printf("%d\n", signo);
                }
            }
        }
        /* If they specified -l, we are all done */
        return EXIT_SUCCESS;
    }

    /* The -q quiet option */
    if (killall && arg[1] == 'q' && arg[2] == '\0') {
        quiet = 1;
        arg = *++argv;
        argc--;
        if (argc < 1) bb_show_usage();
        if (arg[0] != '-') goto do_it_now;
    }

    /* -SIG */
    signo = get_signum(&arg[1]);
    if (signo < 0) { /* || signo > MAX_SIGNUM ? */
        bb_error_msg("bad signal name '%s'", &arg[1]);
        return EXIT_FAILURE;
    }
    arg = *++argv;
    argc--;

do_it_now:

    if (killall5) {
        pid_t sid;
        procps_status_t* p = NULL;

        /* Now stop all processes */
        kill(-1, SIGSTOP);
        /* Find out our own session id */
        pid = getpid();
        sid = getsid(pid);
        /* Now kill all processes except our session */
        while ((p = procps_scan(p, PSSCAN_PID|PSSCAN_SID))) {
            if (p->sid != sid && p->pid != pid && p->pid != 1)
                kill(p->pid, signo);
        }
        /* And let them continue */
        kill(-1, SIGCONT);
        return 0;
    }

    /* Pid or name is required for kill/killall */
    if (argc < 1) {
        puts("You need to specify whom to kill");
        return EXIT_FAILURE;
    }

    if (killall) {
        /* Looks like they want to do a killall.  Do that */
        pid = getpid();
        while (arg) {
            pid_t* pidList;

            pidList = find_pid_by_name(arg);
            if (*pidList == 0) {
                errors++;
                if (!quiet)
                    bb_error_msg("%s: no process killed", arg);
            } else {
                pid_t *pl;

                for (pl = pidList; *pl; pl++) {
                    if (*pl == pid)
                        continue;
                    if (kill(*pl, signo) == 0)
                        continue;
                    errors++;
                    if (!quiet)
                        bb_perror_msg("cannot kill pid %u", (unsigned)*pl);
                }
            }
            free(pidList);
            arg = *++argv;
        }
        return errors;
    }

    /* Looks like they want to do a kill. Do that */
    while (arg) {
        /* Support shell 'space' trick */
        if (arg[0] == ' ')
            arg++;
        pid = bb_strtoi(arg, NULL, 10);
        if (errno) {
            bb_error_msg("bad pid '%s'", arg);
            errors++;
        } else if (kill(pid, signo) != 0) {
            bb_perror_msg("cannot kill pid %d", (int)pid);
            errors++;
        }
        arg = *++argv;
    }
    return errors;
}