xref: /dragonfly/usr.bin/nice/nice.c (revision 0bb9290e)
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. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  * @(#) Copyright (c) 1989, 1993, 1994 The Regents of the University of California.  All rights reserved.
34  * @(#)nice.c	8.2 (Berkeley) 4/16/94
35  * $FreeBSD: src/usr.bin/nice/nice.c,v 1.4.2.1 2002/06/18 08:40:28 tjr Exp $
36  * $DragonFly: src/usr.bin/nice/nice.c,v 1.6 2005/10/09 15:09:02 liamfoy Exp $
37  */
38 
39 #include <sys/time.h>
40 #include <sys/resource.h>
41 
42 #include <ctype.h>
43 #include <err.h>
44 #include <errno.h>
45 #include <limits.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <unistd.h>
50 
51 #define	DEFNICE	10
52 
53 static void	usage(void);
54 
55 int
56 main(int argc, char **argv)
57 {
58 	long niceness = DEFNICE;
59 	int ch;
60 	char *ep;
61 
62 	/* Obsolescent syntax: -number, --number */
63 	if (argc >= 2 && argv[1][0] == '-' && (argv[1][1] == '-' ||
64 	    isdigit(argv[1][1])) && strcmp(argv[1], "--") != 0)
65 		if (asprintf(&argv[1], "-n%s", argv[1] + 1) < 0)
66 			err(1, "asprintf");
67 
68 	while ((ch = getopt(argc, argv, "n:")) != -1) {
69 		switch (ch) {
70 		case 'n':
71 			errno = 0;
72 			niceness = strtol(optarg, &ep, 10);
73 			if (ep == optarg || *ep != '\0' || errno ||
74 			    niceness < INT_MIN || niceness > INT_MAX)
75 				errx(1, "%s: invalid nice value", optarg);
76 			break;
77 		default:
78 			usage();
79 		}
80 	}
81 	argc -= optind;
82 	argv += optind;
83 
84 	if (argc == 0)
85 		usage();
86 
87 	errno = 0;
88 	niceness += getpriority(PRIO_PROCESS, 0);
89 	if (errno)
90 		warn("getpriority");
91 	else if (setpriority(PRIO_PROCESS, 0, (int)niceness))
92 		warn("setpriority");
93 	execvp(*argv, argv);
94 	err(errno == ENOENT || errno == ENOTDIR ? 127 : 126, "%s", *argv);
95 }
96 
97 static void
98 usage(void)
99 {
100 
101 	fprintf(stderr, "usage: nice [-n incr] utility [arguments]\n");
102 	exit(1);
103 }
104