/*
 * skill.c - send a signal to process
 * Copyright 1998-2002 by Albert Cahalan
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include <ctype.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <getopt.h>
#include <limits.h>
#include <pwd.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <unistd.h>

#include "c.h"
#include "fileutils.h"
#include "nsutils.h"
#include "signals.h"
#include "strutils.h"
#include "nls.h"
#include "xalloc.h"
#include "proc/pwcache.h"
#include "proc/devname.h"
#include "rpmatch.h"

#define DEFAULT_NICE 4

struct run_time_conf_t {
    int fast;
    int interactive;
    int verbose;
    int warnings;
    int noaction;
    int debugging;
};
static int tty_count, uid_count, cmd_count, pid_count, namespace_count;
static int *ttys;
static uid_t *uids;
static const char **cmds;
static int *pids;
static char **namespaces;
static int ns_pid;
static proc_t ns_task;

#define ENLIST(thing,addme) do{ \
if(!thing##s) thing##s = xmalloc(sizeof(*thing##s)*saved_argc); \
thing##s[thing##_count++] = addme; \
}while(0)

static int my_pid;
static int saved_argc;

static int sig_or_pri;

enum {
    PROG_UNKNOWN,
    PROG_KILL,
    PROG_SKILL,
    PROG_SNICE
};
static int program = PROG_UNKNOWN;

static void display_kill_version(void)
{
    fprintf(stdout, PROCPS_NG_VERSION);
}

static int ns_flags = 0x3f;
static int parse_namespaces(char *optarg)
{
    char *ptr = optarg, *tmp;
    int len, id;

    ns_flags = 0;
    while (1) {
        if (strchr(ptr, ',') == NULL) {
            len = -1;
            tmp = strdup(ptr);
        } else {
            len = strchr(ptr, ',') - ptr;
            tmp = strndup(ptr, len);
        }

        id = get_ns_id(tmp);
        if (id == -1) {
            fprintf(stderr, "%s is not a valid namespace\n", tmp);
            free(tmp);
            return 1;
        }
        ns_flags |= (1 << id);
        ENLIST(namespace, tmp);

        if (len == -1)
            break;

        ptr+= len + 1;
    }
    return 0;
}

static void unix_print_signals(void)
{
   int pos = 0;
    int i = 0;
    while(++i <= number_of_signals){
        if(i-1) printf("%c", (pos>73)?(pos=0,'\n'):(pos++,' ') );
        pos += printf("%s", signal_number_to_name(i));
    }
    printf("\n");
}

static void pretty_print_signals(void)
{
    int i = 0;
    while(++i <= number_of_signals){
        int n;
        n = printf("%2d %s", i, signal_number_to_name(i));
        if(n>0 && i%7)
            printf("%s", "           \0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0" + n);
        else
            printf("\n");
    }
    if((i-1)%7) printf("\n");
}

/* strtosig is similar to print_given_signals() with exception, that
 * this function takes a string, and converts it to a signal name or
 * a number string depending on which way a round conversion is
 * queried.  Non-existing signals return NULL.  Notice that the
 * returned string should be freed after use.
 */
static char *strtosig(const char *restrict s)
{
    char *converted = NULL, *copy, *p, *endp;
    int i, numsignal = 0;

    copy = strdup(s);
    if (!copy)
        xerrx(EXIT_FAILURE, "cannot duplicate string");
    for (p = copy; *p != '\0'; p++)
        *p = toupper(*p);
    p = copy;
    if (p[0] == 'S' && p[1] == 'I' && p[2] == 'G')
        p += 3;
    if (isdigit(*p)){
        numsignal = strtol(s,&endp,10);
        if(*endp || endp==s)
            return NULL; /* not valid */
    }
    if (numsignal){
        for (i = 0; i < number_of_signals; i++){
            if (numsignal == get_sigtable_num(i)){
                converted = strdup(get_sigtable_name(i));
                break;
            }
        }
    } else {
        for (i = 0; i < number_of_signals; i++){
            if (strcmp(p, get_sigtable_name(i)) == 0){
                converted = malloc(sizeof(char) * 8);
                if (converted)
                    snprintf(converted,
                         sizeof(converted) - 1,
                         "%d", get_sigtable_num(i));
                break;
            }
        }
    }
    free(p);
    return converted;
}

/* kill or nice a process */
static void hurt_proc(int tty, int uid, int pid, const char *restrict const cmd,
              struct run_time_conf_t *run_time)
{
    int failed;
    char dn_buf[1000];
    dev_to_tty(dn_buf, 999, tty, pid, ABBREV_DEV);
    if (run_time->interactive) {
        char *buf;
        size_t len = 0;
        fprintf(stderr, "%-8s %-8s %5d %-16.16s   ? ",
            (char *)dn_buf, user_from_uid(uid), pid, cmd);
        fflush (stdout);
        if (getline(&buf, &len, stdin) == -1)
            return;
        if (rpmatch(buf) < 1) {
            free(buf);
            return;
        }
        free(buf);
    }
    /* do the actual work */
    errno = 0;
    if (program == PROG_SKILL)
        failed = kill(pid, sig_or_pri);
    else
        failed = setpriority(PRIO_PROCESS, pid, sig_or_pri);
    if ((run_time->warnings && failed) || run_time->debugging || run_time->verbose) {
        fprintf(stderr, "%-8s %-8s %5d %-16.16s   ",
            (char *)dn_buf, user_from_uid(uid), pid, cmd);
        perror("");
        return;
    }
    if (run_time->interactive)
        return;
    if (run_time->noaction) {
        printf("%d\n", pid);
        return;
    }
}

/* check one process */
static void check_proc(int pid, struct run_time_conf_t *run_time)
{
    char buf[128];
    struct stat statbuf;
    proc_t task;
    char *tmp;
    int tty;
    int fd;
    int i;
    if (pid == my_pid || pid == 0)
        return;
    /* pid (cmd) state ppid pgrp session tty */
    sprintf(buf, "/proc/%d/stat", pid);
    fd = open(buf, O_RDONLY);
    if (fd == -1) {
        /* process exited maybe */
        if (run_time->warnings)
            xwarn(_("cannot open file %s"), buf);
        return;
    }
    fstat(fd, &statbuf);
    if (uids) {
        /* check the EUID */
        i = uid_count;
        while (i--)
            if (uids[i] == statbuf.st_uid)
                break;
        if (i == -1)
            goto closure;
    }
    if (read(fd, buf, 128) <= 0)
        goto closure;
    buf[127] = '\0';
    tmp = strrchr(buf, ')');
    *tmp++ = '\0';
    i = 5;
    while (i--)
        while (*tmp++ != ' ')
            /* scan to find tty */ ;
    tty = atoi(tmp);
    if (ttys) {
        i = tty_count;
        while (i--)
            if (ttys[i] == tty)
                break;
        if (i == -1)
            goto closure;
    }
    tmp = strchr(buf, '(') + 1;
    if (cmds) {
        i = cmd_count;
        /* fast comparison trick -- useful? */
        while (i--)
            if (cmds[i][0] == *tmp && !strcmp(cmds[i], tmp))
                break;
        if (i == -1)
            goto closure;
    }
    if (ns_pid) {
        if (ns_read(pid, &task))
            goto closure;
        for (i = 0; i < NUM_NS; i++) {
            if (ns_flags & (1 << i)) {
                if (task.ns[i] != ns_task.ns[i])
                    goto closure;
            }
        }
    }
    /* This is where we kill/nice something. */
    /* for debugging purposes?
    fprintf(stderr, "PID %d, UID %d, TTY %d,%d, COMM %s\n",
        pid, statbuf.st_uid, tty >> 8, tty & 0xf, tmp);
    */
    hurt_proc(tty, statbuf.st_uid, pid, tmp, run_time);
 closure:
    /* kill/nice _first_ to avoid PID reuse */
    close(fd);
}

/* debug function */
static void show_lists(void)
{
    int i;

    fprintf(stderr, "signal: %d\n", sig_or_pri);

    fprintf(stderr, "%d TTY: ", tty_count);
    if (ttys) {
        i = tty_count;
        while (i--) {
            fprintf(stderr, "%d,%d%c", (ttys[i] >> 8) & 0xff,
                ttys[i] & 0xff, i ? ' ' : '\n');
        }
    } else
        fprintf(stderr, "\n");

    fprintf(stderr, "%d UID: ", uid_count);
    if (uids) {
        i = uid_count;
        while (i--)
            fprintf(stderr, "%d%c", uids[i], i ? ' ' : '\n');
    } else
        fprintf(stderr, "\n");

    fprintf(stderr, "%d PID: ", pid_count);
    if (pids) {
        i = pid_count;
        while (i--)
            fprintf(stderr, "%d%c", pids[i], i ? ' ' : '\n');
    } else
        fprintf(stderr, "\n");

    fprintf(stderr, "%d CMD: ", cmd_count);
    if (cmds) {
        i = cmd_count;
        while (i--)
            fprintf(stderr, "%s%c", cmds[i], i ? ' ' : '\n');
    } else
        fprintf(stderr, "\n");
}

/* iterate over all PIDs */
static void iterate(struct run_time_conf_t *run_time)
{
    int pid;
    DIR *d;
    struct dirent *de;
    if (pids) {
        pid = pid_count;
        while (pid--)
            check_proc(pids[pid], run_time);
        return;
    }
#if 0
    /* could setuid() and kill -1 to have the kernel wipe out a user */
    if (!ttys && !cmds && !pids && !run_time->interactive) {
    }
#endif
    d = opendir("/proc");
    if (!d)
        xerr(EXIT_FAILURE, "/proc");
    while ((de = readdir(d))) {
        if (de->d_name[0] > '9')
            continue;
        if (de->d_name[0] < '1')
            continue;
        pid = atoi(de->d_name);
        if (pid)
            check_proc(pid, run_time);
    }
    closedir(d);
}

/* kill help */
static void __attribute__ ((__noreturn__)) kill_usage(FILE * out)
{
    fputs(USAGE_HEADER, out);
    fprintf(out,
              _(" %s [options] <pid> [...]\n"), program_invocation_short_name);
    fputs(USAGE_OPTIONS, out);
    fputs(_(" <pid> [...]            send signal to every <pid> listed\n"), out);
    fputs(_(" -<signal>, -s, --signal <signal>\n"
        "                        specify the <signal> to be sent\n"), out);
    fputs(_(" -l, --list=[<signal>]  list all signal names, or convert one to a name\n"), out);
    fputs(_(" -L, --table            list all signal names in a nice table\n"), out);
    fputs(USAGE_SEPARATOR, out);
    fputs(USAGE_HELP, out);
    fputs(USAGE_VERSION, out);
    fprintf(out, USAGE_MAN_TAIL("kill(1)"));
    exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
}

/* skill and snice help */
static void __attribute__ ((__noreturn__)) skillsnice_usage(FILE * out)
{
    fputs(USAGE_HEADER, out);

    if (program == PROG_SKILL) {
        fprintf(out,
            _(" %s [signal] [options] <expression>\n"),
            program_invocation_short_name);
    } else {
        fprintf(out,
            _(" %s [new priority] [options] <expression>\n"),
            program_invocation_short_name);
    }
    fputs(USAGE_OPTIONS, out);
    fputs(_(" -f, --fast         fast mode (not implemented)\n"), out);
    fputs(_(" -i, --interactive  interactive\n"), out);
    fputs(_(" -l, --list         list all signal names\n"), out);
    fputs(_(" -L, --table        list all signal names in a nice table\n"), out);
    fputs(_(" -n, --no-action    do not actually kill processes; just print what would happen\n"), out);
    fputs(_(" -v, --verbose      explain what is being done\n"), out);
    fputs(_(" -w, --warnings     enable warnings (not implemented)\n"), out);
    fputs(USAGE_SEPARATOR, out);
    fputs(_("Expression can be: terminal, user, pid, command.\n"
        "The options below may be used to ensure correct interpretation.\n"), out);
    fputs(_(" -c, --command <command>  expression is a command name\n"), out);
    fputs(_(" -p, --pid <pid>          expression is a process id number\n"), out);
    fputs(_(" -t, --tty <tty>          expression is a terminal\n"), out);
    fputs(_(" -u, --user <username>    expression is a username\n"), out);
    fputs(USAGE_SEPARATOR, out);
    fputs(_("Alternatively, expression can be:\n"), out);
    fputs(_(" --ns <pid>               match the processes that belong to the same\n"
        "                          namespace as <pid>\n"), out);
    fputs(_(" --nslist <ns,...>        list which namespaces will be considered for\n"
        "                          the --ns option; available namespaces are\n:"
            "                          ipc, mnt, net, pid, user, uts\n"), out);

    fputs(USAGE_SEPARATOR, out);
    fputs(USAGE_SEPARATOR, out);
    fputs(USAGE_HELP, out);
    fputs(USAGE_VERSION, out);
    if (program == PROG_SKILL) {
        fprintf(out,
            _("\n"
              "The default signal is TERM. Use -l or -L to list available signals.\n"
              "Particularly useful signals include HUP, INT, KILL, STOP, CONT, and 0.\n"
              "Alternate signals may be specified in three ways: -SIGKILL -KILL -9\n"));
        fprintf(out, USAGE_MAN_TAIL("skill(1)"));
    } else {
        fprintf(out,
            _("\n"
              "The default priority is +4. (snice +4 ...)\n"
              "Priority numbers range from +20 (slowest) to -20 (fastest).\n"
              "Negative priority numbers are restricted to administrative users.\n"));
        fprintf(out, USAGE_MAN_TAIL("snice(1)"));
    }
    exit(out == stderr ? EXIT_FAILURE : EXIT_SUCCESS);
}

static int skill_sig_option(int *argc, char **argv)
{
    int i, nargs = *argc;
    int signo = -1;
    for (i = 1; i < nargs; i++) {
        if (argv[i][0] == '-') {
            signo = signal_name_to_number(argv[i] + 1);
            if (-1 < signo) {
                if (nargs - i) {
                    nargs--;
                    memmove(argv + i, argv + i + 1,
                        sizeof(char *) * (nargs - i));
                }
                return signo;
            }
        }
    }
    return signo;
}

/* kill */
static void __attribute__ ((__noreturn__))
    kill_main(int argc, char **argv)
{
    int signo, i;
    int sigopt = 0;
    int loop = 1;
    long pid;
    int exitvalue = EXIT_SUCCESS;

    static const struct option longopts[] = {
        {"list", optional_argument, NULL, 'l'},
        {"table", no_argument, NULL, 'L'},
        {"signal", required_argument, NULL, 's'},
        {"help", no_argument, NULL, 'h'},
        {"version", no_argument, NULL, 'V'},
        {NULL, 0, NULL, 0}
    };

    setlocale (LC_ALL, "");
    bindtextdomain(PACKAGE, LOCALEDIR);
    textdomain(PACKAGE);
    atexit(close_stdout);

    if (argc < 2)
        kill_usage(stderr);

    signo = skill_sig_option(&argc, argv);
    if (signo < 0)
        signo = SIGTERM;
    else
        sigopt++;

    opterr=0; /* suppress errors on -123 */
    while (loop == 1 && (i = getopt_long(argc, argv, "l::Ls:hV", longopts, NULL)) != -1)
        switch (i) {
        case 'l':
            if (optarg) {
                char *s;
                s = strtosig(optarg);
                if (s)
                    printf("%s\n", s);
                else
                    xwarnx(_("unknown signal name %s"),
                          optarg);
                free(s);
            } else {
                unix_print_signals();
            }
            exit(EXIT_SUCCESS);
        case 'L':
            pretty_print_signals();
            exit(EXIT_SUCCESS);
        case 's':
            signo = signal_name_to_number(optarg);
            break;
        case 'h':
            kill_usage(stdout);
        case 'V':
            display_kill_version();
            exit(EXIT_SUCCESS);
        case '?':
            if (!isdigit(optopt)) {
                xwarnx(_("invalid argument %c"), optopt);
                kill_usage(stderr);
            } else {
                /* Special case for signal digit negative
                 * PIDs */
                pid = (long)('0' - optopt);
                if (kill((pid_t)pid, signo) != 0)
                exitvalue = EXIT_FAILURE;
                exit(exitvalue);
            }
            loop=0;
            break;
        default:
            kill_usage(stderr);
        }

    argc -= optind + sigopt;
    argv += optind;

    for (i = 0; i < argc; i++) {
        pid = strtol_or_err(argv[i], _("failed to parse argument"));
        if (!kill((pid_t) pid, signo))
            continue;
        exitvalue = EXIT_FAILURE;
        continue;
    }

    exit(exitvalue);
}

#if 0
static void _skillsnice_usage(int line)
{
    fprintf(stderr, _("something at line %d\n"), line);
    skillsnice_usage(stderr);
}

#define skillsnice_usage() _skillsnice_usage(__LINE__)
#endif

#define NEXTARG (argc?( argc--, ((argptr=*++argv)) ):NULL)

/* common skill/snice argument parsing code */

static int snice_prio_option(int *argc, char **argv)
{
    int i = 1, nargs = *argc;
    long prio = DEFAULT_NICE;

    while (i < nargs) {
        if ((argv[i][0] == '-' || argv[i][0] == '+')
            && isdigit(argv[i][1])) {
            prio = strtol_or_err(argv[i],
                         _("failed to parse argument"));
            if (prio < INT_MIN || INT_MAX < prio)
                xerrx(EXIT_FAILURE,
                     _("priority %lu out of range"), prio);
            nargs--;
            if (nargs - i)
                memmove(argv + i, argv + i + 1,
                    sizeof(char *) * (nargs - i));
        } else
            i++;
    }
    *argc = nargs;
    return (int)prio;
}

static void skillsnice_parse(int argc,
                 char **argv, struct run_time_conf_t *run_time)
{
    int signo = -1;
    int prino = DEFAULT_NICE;
    int ch, i;

    enum {
        NS_OPTION = CHAR_MAX + 1,
        NSLIST_OPTION,
    };

    static const struct option longopts[] = {
        {"command", required_argument, NULL, 'c'},
        {"debug", no_argument, NULL, 'd'},
        {"fast", no_argument, NULL, 'f'},
        {"interactive", no_argument, NULL, 'i'},
        {"list", no_argument, NULL, 'l'},
        {"no-action", no_argument, NULL, 'n'},
        {"pid", required_argument, NULL, 'p'},
        {"table", no_argument, NULL, 'L'},
        {"tty", required_argument, NULL, 't'},
        {"user", required_argument, NULL, 'u'},
        {"ns", required_argument, NULL, NS_OPTION},
        {"nslist", required_argument, NULL, NSLIST_OPTION},
        {"verbose", no_argument, NULL, 'v'},
        {"warnings", no_argument, NULL, 'w'},
        {"help", no_argument, NULL, 'h'},
        {"version", no_argument, NULL, 'V'},
        {NULL, 0, NULL, 0}
    };

    if (argc < 2)
        skillsnice_usage(stderr);

    sig_or_pri = -1;

    if (program == PROG_SNICE)
        prino = snice_prio_option(&argc, argv);
    else if (program == PROG_SKILL) {
        signo = skill_sig_option(&argc, argv);
        if (-1 < signo) {
            sig_or_pri = signo;
            argc -= 1;
        }
    }

    pid_count = 0;

    while ((ch =
        getopt_long(argc, argv, "c:dfilnp:Lt:u:vwhV", longopts,
                NULL)) != -1)
        switch (ch) {
        case 'c':
            ENLIST(cmd, optarg);
            break;
        case 'd':
            run_time->debugging = 1;
            break;
        case 'f':
            run_time->fast = 1;
            break;
        case 'i':
            run_time->interactive = 1;
            break;
        case 'l':
            unix_print_signals();
            exit(EXIT_SUCCESS);
        case 'n':
            run_time->noaction = 1;
            break;
        case 'p':
            ENLIST(pid,
                   strtol_or_err(optarg,
                         _("failed to parse argument")));
            pid_count++;
            break;
        case 'L':
            pretty_print_signals();
            exit(EXIT_SUCCESS);
        case 't':
            {
                struct stat sbuf;
                char path[32];
                snprintf(path, 32, "/dev/%s", optarg);
                if (stat(path, &sbuf) >= 0
                    && S_ISCHR(sbuf.st_mode)) {
                    ENLIST(tty, sbuf.st_rdev);
                }
            }
            break;
        case 'u':
            {
                struct passwd *passwd_data;
                passwd_data = getpwnam(optarg);
                if (passwd_data) {
                    ENLIST(uid, passwd_data->pw_uid);
                }
            }
            break;
        case NS_OPTION:
            ns_pid = atoi(optarg);
            if (ns_pid == 0) {
                xwarnx(_("invalid pid number %s"), optarg);
                kill_usage(stderr);
            }
            if (ns_read(ns_pid, &ns_task)) {
                xwarnx(_("error reading reference namespace "
                     "information"));
                kill_usage(stderr);
            }

            break;
        case NSLIST_OPTION:
            if (parse_namespaces(optarg)) {
                xwarnx(_("invalid namespace list"));
                kill_usage(stderr);
            }
            break;
        case 'v':
            run_time->verbose = 1;
            break;
        case 'w':
            run_time->warnings = 1;
            break;
        case 'h':
            skillsnice_usage(stdout);
        case 'V':
            display_kill_version();
            exit(EXIT_SUCCESS);
        default:
            skillsnice_usage(stderr);
        }

    argc -= optind;
    argv += optind;

    for (i = 0; i < argc; i++) {
        long num;
        char *end = NULL;
        errno = 0;
        num = strtol(argv[0], &end, 10);
        if (errno == 0 && argv[0] != end && end != NULL && *end == '\0') {
            ENLIST(pid, num);
            pid_count++;
        } else {
            ENLIST(cmd, argv[0]);
        }
        argv++;
    }

    /* No more arguments to process. Must sanity check. */
    if (!tty_count && !uid_count && !cmd_count && !pid_count && !ns_pid)
        xerrx(EXIT_FAILURE, _("no process selection criteria"));
    if ((run_time->fast | run_time->interactive | run_time->
         verbose | run_time->warnings | run_time->noaction) & ~1)
        xerrx(EXIT_FAILURE, _("general flags may not be repeated"));
    if (run_time->interactive
        && (run_time->verbose | run_time->fast | run_time->noaction))
        xerrx(EXIT_FAILURE, _("-i makes no sense with -v, -f, and -n"));
    if (run_time->verbose && (run_time->interactive | run_time->fast))
        xerrx(EXIT_FAILURE, _("-v makes no sense with -i and -f"));
    if (run_time->noaction) {
        program = PROG_SKILL;
        /* harmless */
        sig_or_pri = 0;
    }
    if (program == PROG_SNICE)
        sig_or_pri = prino;
    else if (sig_or_pri < 0)
        sig_or_pri = SIGTERM;
}

/* main body */
int main(int argc, char ** argv)
{
#ifdef HAVE_PROGRAM_INVOCATION_NAME
    program_invocation_name = program_invocation_short_name;
#endif
    struct run_time_conf_t run_time;
    memset(&run_time, 0, sizeof(struct run_time_conf_t));
    my_pid = getpid();

    if (strcmp(program_invocation_short_name, "kill") == 0 ||
        strcmp(program_invocation_short_name, "lt-kill") == 0)
        program = PROG_KILL;
    else if (strcmp(program_invocation_short_name, "skill") == 0 ||
         strcmp(program_invocation_short_name, "lt-skill") == 0)
        program = PROG_SKILL;
    else if (strcmp(program_invocation_short_name, "snice") == 0 ||
         strcmp(program_invocation_short_name, "lt-snice") == 0)
        program = PROG_SNICE;

    switch (program) {
    case PROG_SNICE:
    case PROG_SKILL:
        setpriority(PRIO_PROCESS, my_pid, -20);
        skillsnice_parse(argc, argv, &run_time);
        if (run_time.debugging)
            show_lists();
        iterate(&run_time);
        break;
    case PROG_KILL:
        kill_main(argc, argv);
        break;
    default:
        fprintf(stderr, _("skill: \"%s\" is not supported\n"),
            program_invocation_short_name);
        fprintf(stderr, USAGE_MAN_TAIL("skill(1)"));
        return EXIT_FAILURE;
    }
    return EXIT_SUCCESS;
}