xref: /freebsd/usr.bin/nice/nice.c (revision 2be1a816b9ff69588e55be0a84cbe2a31efc0f2f)
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 
34 #ifndef lint
35 static const char copyright[] =
36 "@(#) Copyright (c) 1989, 1993, 1994\n\
37 	The Regents of the University of California.  All rights reserved.\n";
38 #endif /* not lint */
39 
40 #if 0
41 #ifndef lint
42 static char sccsid[] = "@(#)nice.c	8.2 (Berkeley) 4/16/94";
43 #endif /* not lint */
44 #endif
45 
46 #include <sys/cdefs.h>
47 __FBSDID("$FreeBSD$");
48 
49 #include <sys/types.h>
50 #include <sys/time.h>
51 #include <sys/resource.h>
52 
53 #include <ctype.h>
54 #include <err.h>
55 #include <errno.h>
56 #include <limits.h>
57 #include <stdio.h>
58 #include <stdlib.h>
59 #include <unistd.h>
60 #include <string.h>
61 
62 #define	DEFNICE	10
63 
64 void usage(void);
65 
66 int
67 main(int argc, char *argv[])
68 {
69 	long niceness = DEFNICE;
70 	int ch;
71 	char *ep;
72 
73 	/* Obsolescent syntax: -number, --number */
74 	if (argc >= 2 && argv[1][0] == '-' && (argv[1][1] == '-' ||
75 	    isdigit((unsigned char)argv[1][1])) && strcmp(argv[1], "--") != 0)
76 		if (asprintf(&argv[1], "-n%s", argv[1] + 1) < 0)
77 			err(1, "asprintf");
78 
79 	while ((ch = getopt(argc, argv, "n:")) != -1) {
80 		switch (ch) {
81 		case 'n':
82 			errno = 0;
83 			niceness = strtol(optarg, &ep, 10);
84 			if (ep == optarg || *ep != '\0' || errno ||
85 			    niceness < INT_MIN || niceness > INT_MAX)
86 				errx(1, "%s: invalid nice value", optarg);
87 			break;
88 		default:
89 			usage();
90 		}
91 	}
92 	argc -= optind;
93 	argv += optind;
94 
95 	if (argc == 0)
96 		usage();
97 
98 	errno = 0;
99 	niceness += getpriority(PRIO_PROCESS, 0);
100 	if (errno)
101 		warn("getpriority");
102 	else if (setpriority(PRIO_PROCESS, 0, (int)niceness))
103 		warn("setpriority");
104 	execvp(*argv, argv);
105 	err(errno == ENOENT ? 127 : 126, "%s", *argv);
106 }
107 
108 void
109 usage(void)
110 {
111 
112 	(void)fprintf(stderr,
113 	    "usage: nice [-n increment] utility [argument ...]\n");
114 	exit(1);
115 }
116