xref: /freebsd/usr.bin/nice/nice.c (revision 193d9e768ba63fcfb187cfd17f461f7d41345048)
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 
30 #ifndef lint
31 static const char copyright[] =
32 "@(#) Copyright (c) 1989, 1993, 1994\n\
33 	The Regents of the University of California.  All rights reserved.\n";
34 #endif /* not lint */
35 
36 #if 0
37 #ifndef lint
38 static char sccsid[] = "@(#)nice.c	8.2 (Berkeley) 4/16/94";
39 #endif /* not lint */
40 #endif
41 
42 #include <sys/cdefs.h>
43 __FBSDID("$FreeBSD$");
44 
45 #include <sys/types.h>
46 #include <sys/time.h>
47 #include <sys/resource.h>
48 
49 #include <ctype.h>
50 #include <err.h>
51 #include <errno.h>
52 #include <limits.h>
53 #include <stdio.h>
54 #include <stdlib.h>
55 #include <unistd.h>
56 #include <string.h>
57 
58 #define	DEFNICE	10
59 
60 void usage(void);
61 
62 int
63 main(int argc, char *argv[])
64 {
65 	long niceness = DEFNICE;
66 	int ch;
67 	char *ep;
68 
69 	/* Obsolescent syntax: -number, --number */
70 	if (argc >= 2 && argv[1][0] == '-' && (argv[1][1] == '-' ||
71 	    isdigit((unsigned char)argv[1][1])) && strcmp(argv[1], "--") != 0)
72 		if (asprintf(&argv[1], "-n%s", argv[1] + 1) < 0)
73 			err(1, "asprintf");
74 
75 	while ((ch = getopt(argc, argv, "n:")) != -1) {
76 		switch (ch) {
77 		case 'n':
78 			errno = 0;
79 			niceness = strtol(optarg, &ep, 10);
80 			if (ep == optarg || *ep != '\0' || errno ||
81 			    niceness < INT_MIN || niceness > INT_MAX)
82 				errx(1, "%s: invalid nice value", optarg);
83 			break;
84 		default:
85 			usage();
86 		}
87 	}
88 	argc -= optind;
89 	argv += optind;
90 
91 	if (argc == 0)
92 		usage();
93 
94 	errno = 0;
95 	niceness += getpriority(PRIO_PROCESS, 0);
96 	if (errno)
97 		warn("getpriority");
98 	else if (setpriority(PRIO_PROCESS, 0, (int)niceness))
99 		warn("setpriority");
100 	execvp(*argv, argv);
101 	err(errno == ENOENT ? 127 : 126, "%s", *argv);
102 }
103 
104 void
105 usage(void)
106 {
107 
108 	(void)fprintf(stderr,
109 	    "usage: nice [-n increment] utility [argument ...]\n");
110 	exit(1);
111 }
112