xref: /freebsd/usr.bin/nice/nice.c (revision 5b31cc94b10d4bb7109c6b27940a0fc76a44a331)
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 #endif
40 
41 #include <sys/cdefs.h>
42 #include <sys/types.h>
43 #include <sys/time.h>
44 #include <sys/resource.h>
45 
46 #include <ctype.h>
47 #include <err.h>
48 #include <errno.h>
49 #include <limits.h>
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <unistd.h>
53 #include <string.h>
54 
55 #define	DEFNICE	10
56 
57 void usage(void);
58 
59 int
60 main(int argc, char *argv[])
61 {
62 	long niceness = DEFNICE;
63 	int ch;
64 	char *ep;
65 
66 	/* Obsolescent syntax: -number, --number */
67 	if (argc >= 2 && argv[1][0] == '-' && (argv[1][1] == '-' ||
68 	    isdigit((unsigned char)argv[1][1])) && strcmp(argv[1], "--") != 0)
69 		if (asprintf(&argv[1], "-n%s", argv[1] + 1) < 0)
70 			err(1, "asprintf");
71 
72 	while ((ch = getopt(argc, argv, "n:")) != -1) {
73 		switch (ch) {
74 		case 'n':
75 			errno = 0;
76 			niceness = strtol(optarg, &ep, 10);
77 			if (ep == optarg || *ep != '\0' || errno ||
78 			    niceness < INT_MIN || niceness > INT_MAX)
79 				errx(1, "%s: invalid nice value", optarg);
80 			break;
81 		default:
82 			usage();
83 		}
84 	}
85 	argc -= optind;
86 	argv += optind;
87 
88 	if (argc == 0)
89 		usage();
90 
91 	errno = 0;
92 	niceness += getpriority(PRIO_PROCESS, 0);
93 	if (errno)
94 		warn("getpriority");
95 	else if (setpriority(PRIO_PROCESS, 0, (int)niceness))
96 		warn("setpriority");
97 	execvp(*argv, argv);
98 	err(errno == ENOENT ? 127 : 126, "%s", *argv);
99 }
100 
101 void
102 usage(void)
103 {
104 
105 	(void)fprintf(stderr,
106 	    "usage: nice [-n increment] utility [argument ...]\n");
107 	exit(1);
108 }
109