xref: /dragonfly/usr.bin/nice/nice.c (revision dc71b7ab)
1 /*
2  * Copyright (c) 1989, 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * @(#) Copyright (c) 1989, 1993, 1994 The Regents of the University of California.  All rights reserved.
30  * @(#)nice.c	8.2 (Berkeley) 4/16/94
31  * $FreeBSD: src/usr.bin/nice/nice.c,v 1.4.2.1 2002/06/18 08:40:28 tjr Exp $
32  * $DragonFly: src/usr.bin/nice/nice.c,v 1.6 2005/10/09 15:09:02 liamfoy Exp $
33  */
34 
35 #include <sys/time.h>
36 #include <sys/resource.h>
37 
38 #include <ctype.h>
39 #include <err.h>
40 #include <errno.h>
41 #include <limits.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <unistd.h>
46 
47 #define	DEFNICE	10
48 
49 static void	usage(void);
50 
51 int
main(int argc,char ** argv)52 main(int argc, char **argv)
53 {
54 	long niceness = DEFNICE;
55 	int ch;
56 	char *ep;
57 
58 	/* Obsolescent syntax: -number, --number */
59 	if (argc >= 2 && argv[1][0] == '-' && (argv[1][1] == '-' ||
60 	    isdigit(argv[1][1])) && strcmp(argv[1], "--") != 0)
61 		if (asprintf(&argv[1], "-n%s", argv[1] + 1) < 0)
62 			err(1, "asprintf");
63 
64 	while ((ch = getopt(argc, argv, "n:")) != -1) {
65 		switch (ch) {
66 		case 'n':
67 			errno = 0;
68 			niceness = strtol(optarg, &ep, 10);
69 			if (ep == optarg || *ep != '\0' || errno ||
70 			    niceness < INT_MIN || niceness > INT_MAX)
71 				errx(1, "%s: invalid nice value", optarg);
72 			break;
73 		default:
74 			usage();
75 		}
76 	}
77 	argc -= optind;
78 	argv += optind;
79 
80 	if (argc == 0)
81 		usage();
82 
83 	errno = 0;
84 	niceness += getpriority(PRIO_PROCESS, 0);
85 	if (errno)
86 		warn("getpriority");
87 	else if (setpriority(PRIO_PROCESS, 0, (int)niceness))
88 		warn("setpriority");
89 	execvp(*argv, argv);
90 	err(errno == ENOENT || errno == ENOTDIR ? 127 : 126, "%s", *argv);
91 }
92 
93 static void
usage(void)94 usage(void)
95 {
96 
97 	fprintf(stderr, "usage: nice [-n incr] utility [arguments]\n");
98 	exit(1);
99 }
100