/*-
 * SPDX-License-Identifier: BSD-4-Clause
 *
 * Copyright (c) 1994 David Greenman
 * Copyright (c) 1994 Henrik Vestergaard Draboel (hvd@terry.ping.dk)
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Henrik Vestergaard Draboel.
 *      This product includes software developed by David Greenman.
 * 4. Neither the names of the authors nor the names of contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS 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 AUTHORS 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 <sys/param.h>
#include <sys/rtprio.h>

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

static int parseint(const char *, const char *);
static void usage(void) __dead2;

int
main(int argc, char *argv[])
{
        struct rtprio rtp;
        const char *progname;
        pid_t proc = 0;

        progname = getprogname();

        if (strcmp(progname, "rtprio") == 0)
                rtp.type = RTP_PRIO_REALTIME;
        else if (strcmp(progname, "idprio") == 0)
                rtp.type = RTP_PRIO_IDLE;
        else
                errx(1, "invalid progname");

        switch (argc) {
        case 2:
                proc = parseint(argv[1], "pid");
                proc = abs(proc);
                /* FALLTHROUGH */
        case 1:
                if (rtprio(RTP_LOOKUP, proc, &rtp) != 0)
                        err(1, "RTP_LOOKUP");
                switch (rtp.type) {
                case RTP_PRIO_REALTIME:
                case RTP_PRIO_FIFO:
                        warnx("realtime priority %d", rtp.prio);
                        break;
                case RTP_PRIO_NORMAL:
                        warnx("normal priority");
                        break;
                case RTP_PRIO_IDLE:
                        warnx("idle priority %d", rtp.prio);
                        break;
                default:
                        errx(1, "invalid priority type %d", rtp.type);
                        break;
                }
                exit(0);
        default:
                if (argv[1][0] == '-' || isdigit(argv[1][0])) {
                        if (argv[1][0] == '-') {
                                if (strcmp(argv[1], "-t") == 0) {
                                        rtp.type = RTP_PRIO_NORMAL;
                                        rtp.prio = 0;
                                } else {
                                        usage();
                                        break;
                                }
                        } else
                                rtp.prio = parseint(argv[1], "priority");
                } else {
                        usage();
                        break;
                }

                if (argv[2][0] == '-') {
                        proc = parseint(argv[2], "pid");
                        proc = abs(proc);
                }

                if (rtprio(RTP_SET, proc, &rtp) != 0)
                        err(1, "RTP_SET");

                if (proc == 0) {
                        execvp(argv[2], &argv[2]);
                        err(1, "execvp: %s", argv[2]);
                }
                exit(0);
        }
        /* NOTREACHED */
}

static int
parseint(const char *str, const char *errname)
{
        char *endp;
        long res;

        errno = 0;
        res = strtol(str, &endp, 10);
        if (errno != 0 || endp == str || *endp != '\0')
                errx(1, "%s must be a number", errname);
        if (res >= INT_MAX)
                errx(1, "Integer overflow parsing %s", errname);
        return (res);
}

static void
usage(void)
{

        (void) fprintf(stderr, "%s\n%s\n%s\n%s\n%s\n%s\n",
                "usage: [id|rt]prio",
                "       [id|rt]prio [-]pid",
                "       [id|rt]prio priority command [args]",
                "       [id|rt]prio priority -pid",
                "       [id|rt]prio -t command [args]",
                "       [id|rt]prio -t -pid");
        exit(1);
}