/*      $OpenBSD: kill.c,v 1.15 2025/04/24 14:15:29 schwarze Exp $      */
/*      $NetBSD: kill.c,v 1.11 1995/09/07 06:30:27 jtc Exp $    */

/*
 * Copyright (c) 1988, 1993, 1994
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <limits.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

extern  char *__progname;

void nosig(char *);
void printsignals(FILE *);
int signame_to_signum(char *);
void usage(void);

int
main(int argc, char *argv[])
{
        int errors, numsig, pid;
        const char *errstr;

        if (pledge("stdio proc", NULL) == -1)
                err(1, "pledge");

        if (argc < 2)
                usage();

        numsig = SIGTERM;

        argc--, argv++;
        if (!strcmp(*argv, "-l")) {
                argc--, argv++;
                if (argc > 0 && !strcmp(*argv, "--"))
                        argc--, argv++;
                if (argc > 1)
                        usage();
                if (argc == 1) {
                        if (!isdigit((unsigned char)**argv))
                                usage();
                        numsig = strtonum(*argv, 1, NSIG + 127, &errstr);
                        if (errstr != NULL) {
                                if (errno == ERANGE)
                                        nosig(*argv);
                                errx(1, "illegal signal number: %s", *argv);
                        }
                        printf("%s\n", sys_signame[numsig & 127]);
                        exit(0);
                }
                printsignals(stdout);
                exit(0);
        }

        if (!strcmp(*argv, "-s")) {
                argc--, argv++;
                if (argc > 0 && !strcmp(*argv, "--"))
                        argc--, argv++;
                if (argc < 1) {
                        warnx("option requires an argument -- s");
                        usage();
                }
                if (strcmp(*argv, "0")) {
                        if ((numsig = signame_to_signum(*argv)) < 0)
                                nosig(*argv);
                } else
                        numsig = 0;
                argc--, argv++;
        } else if (**argv == '-') {
                if (strcmp(*argv, "--")) {
                        ++*argv;
                        if (isalpha((unsigned char)**argv)) {
                                if ((numsig = signame_to_signum(*argv)) < 0)
                                        nosig(*argv);
                        } else if (isdigit((unsigned char)**argv)) {
                                numsig = strtonum(*argv, 0, NSIG - 1, &errstr);
                                if (errstr != NULL) {
                                        if (errno == ERANGE)
                                                nosig(*argv);
                                        errx(1, "illegal signal number: %s", *argv);
                                }
                        } else
                                nosig(*argv);
                }
                argc--, argv++;
        }

        if (argc == 0)
                usage();

        for (errors = 0; argc; argc--, argv++) {
                pid = strtonum(*argv, -INT_MAX, INT_MAX, &errstr);
                if (errstr != NULL) {
                        warnx("illegal process id: %s", *argv);
                        errors = 1;
                } else if (kill(pid, numsig) == -1) {
                        warn("%s", *argv);
                        errors = 1;
                }
        }

        exit(errors);
}

int
signame_to_signum(char *sig)
{
        int n;

        if (!strncasecmp(sig, "sig", 3))
                sig += 3;
        for (n = 1; n < NSIG; n++) {
                if (!strcasecmp(sys_signame[n], sig))
                        return (n);
        }
        return (-1);
}

void
nosig(char *name)
{

        warnx("unknown signal %s; valid signals:", name);
        printsignals(stderr);
        exit(1);
}

void
printsignals(FILE *fp)
{
        int n;

        for (n = 1; n < NSIG; n++) {
                (void)fprintf(fp, "%s", sys_signame[n]);
                if (n == (NSIG / 2) || n == (NSIG - 1))
                        (void)fprintf(fp, "\n");
                else
                        (void)fprintf(fp, " ");
        }
}

void
usage(void)
{
        (void)fprintf(stderr, "usage: %s [-signal_number | -signal_name |"
            " -s signal_name] pid ...\n", __progname);
        (void)fprintf(stderr, "       %s -l [exit_status]\n", __progname);
        exit(1);
}