xref: /freebsd/usr.bin/nice/nice.c (revision 3c4ba5f55438f7afd4f4b0b56f88f2bb505fd6a6)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1989, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #ifndef lint
33 static const char copyright[] =
34 "@(#) Copyright (c) 1989, 1993, 1994\n\
35 	The Regents of the University of California.  All rights reserved.\n";
36 #endif /* not lint */
37 
38 #if 0
39 #ifndef lint
40 static char sccsid[] = "@(#)nice.c	8.2 (Berkeley) 4/16/94";
41 #endif /* not lint */
42 #endif
43 
44 #include <sys/cdefs.h>
45 __FBSDID("$FreeBSD$");
46 
47 #include <sys/types.h>
48 #include <sys/time.h>
49 #include <sys/resource.h>
50 
51 #include <ctype.h>
52 #include <err.h>
53 #include <errno.h>
54 #include <limits.h>
55 #include <stdio.h>
56 #include <stdlib.h>
57 #include <unistd.h>
58 #include <string.h>
59 
60 #define	DEFNICE	10
61 
62 void usage(void);
63 
64 int
65 main(int argc, char *argv[])
66 {
67 	long niceness = DEFNICE;
68 	int ch;
69 	char *ep;
70 
71 	/* Obsolescent syntax: -number, --number */
72 	if (argc >= 2 && argv[1][0] == '-' && (argv[1][1] == '-' ||
73 	    isdigit((unsigned char)argv[1][1])) && strcmp(argv[1], "--") != 0)
74 		if (asprintf(&argv[1], "-n%s", argv[1] + 1) < 0)
75 			err(1, "asprintf");
76 
77 	while ((ch = getopt(argc, argv, "n:")) != -1) {
78 		switch (ch) {
79 		case 'n':
80 			errno = 0;
81 			niceness = strtol(optarg, &ep, 10);
82 			if (ep == optarg || *ep != '\0' || errno ||
83 			    niceness < INT_MIN || niceness > INT_MAX)
84 				errx(1, "%s: invalid nice value", optarg);
85 			break;
86 		default:
87 			usage();
88 		}
89 	}
90 	argc -= optind;
91 	argv += optind;
92 
93 	if (argc == 0)
94 		usage();
95 
96 	errno = 0;
97 	niceness += getpriority(PRIO_PROCESS, 0);
98 	if (errno)
99 		warn("getpriority");
100 	else if (setpriority(PRIO_PROCESS, 0, (int)niceness))
101 		warn("setpriority");
102 	execvp(*argv, argv);
103 	err(errno == ENOENT ? 127 : 126, "%s", *argv);
104 }
105 
106 void
107 usage(void)
108 {
109 
110 	(void)fprintf(stderr,
111 	    "usage: nice [-n increment] utility [argument ...]\n");
112 	exit(1);
113 }
114