usr/src/cmd/nice/nice.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
  23 /*        All Rights Reserved   */
  24
  25
  26 /*
  27  * Copyright 2000-2003 Sun Microsystems, Inc.  All rights reserved.
  28  * Use is subject to license terms.
  29  */
  30
  31 #pragma ident   "%Z%%M% %I%     %E% SMI"
  32
  33 /*
  34 **      nice
  35 */
  36
  37
  38 #include        <stdio.h>
  39 #include        <locale.h>
  40 #include        <stdlib.h>
  41 #include        <string.h>
  42 #include        <unistd.h>
  43 #include        <errno.h>
  44
  45
  46 static void usage(void);
  47
  48 int
  49 main(int argc, char *argv[])
  50 {
  51         long    nicarg = 10;
  52
  53         (void) setlocale(LC_ALL, "");
  54 #if !defined(TEXT_DOMAIN)
  55 #define TEXT_DOMAIN     "SYS_TEST"
  56 #endif
  57         (void) textdomain(TEXT_DOMAIN);
  58
  59
  60         if (argc < 2)
  61                 usage();
  62
  63
  64         if (argv[1][0] == '-') {
  65                 if (strcmp(argv[1], "--") == 0) {
  66                         argv++;
  67                         argc--;
  68                 } else {
  69                         register char   *p = argv[1];
  70                         char    *nicarg_str;
  71                         char    *end_ptr;
  72
  73                         if (*++p == 'n') {      /* -n55 new form, XCU4 */
  74                                 /*
  75                                  * for situations like -n-10
  76                                  * else case assigns p instead of argv
  77                                  */
  78                                 if (!(*++p)) {
  79                                         /* Next arg is priority */
  80                                         argv++;
  81                                         argc--;
  82                                         if (argc < 2)
  83                                                 usage();
  84                                         nicarg_str = argv[1];
  85                                 } else {
  86                                         /* Priority embedded eg. -n-10 */
  87                                         nicarg_str = p;
  88                                 }
  89                         } else {        /* -55 obs form, XCU4 */
  90                                 nicarg_str = &argv[1][1];
  91                         }
  92                         nicarg = strtol(nicarg_str, &end_ptr, 10);
  93                         if (*end_ptr) {
  94                                 (void) fprintf(stderr,
  95                                 gettext("nice: argument must be numeric.\n"));
  96                                 usage();
  97                         }
  98
  99                         if( --argc < 2 )
 100                                 usage();
 101
 102                         argv++;
 103                         if (strcmp(argv[1], "--") == 0) {
 104                                 argv++;
 105                                 argc--;
 106                         }
 107                 }
 108         }
 109
 110         if (argc < 2)
 111                 usage();
 112
 113         errno = 0;
 114         if (nice(nicarg) == -1) {
 115                 /*
 116                  * Could be an error or a legitimate return value.
 117                  * The only error we care about is EINVAL, which will
 118                  * be returned by the scheduling class we are in if
 119                  * nice is invalid for this class.
 120                  * For any error other than EINVAL
 121                  * we will go ahead and exec the command even though
 122                  * the priority change failed.
 123                  */
 124                 if (errno == EINVAL) {
 125                         (void) fprintf(stderr, gettext(
 126                             "nice: invalid operation; "
 127                             "scheduling class does not support nice\n"));
 128                         return (2);
 129                 }
 130         }
 131         (void) execvp(argv[1], &argv[1]);
 132         (void) fprintf(stderr, gettext("%s: %s\n"), strerror(errno), argv[1]);
 133         /*
 134          * POSIX.2 exit status:
 135          * 127 if utility is not found.
 136          * 126 if utility cannot be invoked.
 137          */
 138         return (errno == ENOENT || errno == ENOTDIR ? 127 : 126);
 139 }
 140
 141 static void
 142 usage()
 143 {
 144         (void) fprintf(stderr,
 145         gettext("nice: usage: nice [-n increment] utility [argument ...]\n"));
 146         exit(2);
 147 }