cmd/nice/nice.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*  Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*    All Rights Reserved   */


/*
 * Copyright 2000-2003 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

/*
**  nice
*/


#include    <stdio.h>
#include    <locale.h>
#include    <stdlib.h>
#include    <string.h>
#include    <unistd.h>
#include    <errno.h>


static void usage(void);

int
main(int argc, char *argv[])
{
    long    nicarg = 10;

    (void) setlocale(LC_ALL, "");
#if !defined(TEXT_DOMAIN)
#define TEXT_DOMAIN "SYS_TEST"
#endif
    (void) textdomain(TEXT_DOMAIN);


    if (argc < 2)
        usage();


    if (argv[1][0] == '-') {
        if (strcmp(argv[1], "--") == 0) {
            argv++;
            argc--;
        } else {
            register char   *p = argv[1];
            char    *nicarg_str;
            char    *end_ptr;

            if (*++p == 'n') {  /* -n55 new form, XCU4 */
                /*
                 * for situations like -n-10
                 * else case assigns p instead of argv
                 */
                if (!(*++p)) {
                    /* Next arg is priority */
                    argv++;
                    argc--;
                    if (argc < 2)
                        usage();
                    nicarg_str = argv[1];
                } else {
                    /* Priority embedded eg. -n-10 */
                    nicarg_str = p;
                }
            } else {    /* -55 obs form, XCU4 */
                nicarg_str = &argv[1][1];
            }
            nicarg = strtol(nicarg_str, &end_ptr, 10);
            if (*end_ptr) {
                (void) fprintf(stderr,
                gettext("nice: argument must be numeric.\n"));
                usage();
            }

            if( --argc < 2 )
                usage();

            argv++;
            if (strcmp(argv[1], "--") == 0) {
                argv++;
                argc--;
            }
        }
    }

    if (argc < 2)
        usage();

    errno = 0;
    if (nice(nicarg) == -1) {
        /*
         * Could be an error or a legitimate return value.
         * The only error we care about is EINVAL, which will
         * be returned by the scheduling class we are in if
         * nice is invalid for this class.
         * For any error other than EINVAL
         * we will go ahead and exec the command even though
         * the priority change failed.
         */
        if (errno == EINVAL) {
            (void) fprintf(stderr, gettext(
                "nice: invalid operation; "
                "scheduling class does not support nice\n"));
            return (2);
        }
    }
    (void) execvp(argv[1], &argv[1]);
    (void) fprintf(stderr, gettext("%s: %s\n"), strerror(errno), argv[1]);
    /*
     * POSIX.2 exit status:
     * 127 if utility is not found.
     * 126 if utility cannot be invoked.
     */
    return (errno == ENOENT || errno == ENOTDIR ? 127 : 126);
}

static void
usage()
{
    (void) fprintf(stderr,
    gettext("nice: usage: nice [-n increment] utility [argument ...]\n"));
    exit(2);
}