xref: /freebsd/usr.bin/renice/renice.c (revision b1f9167f94059fd55c630891d359bcff987bd7eb)
1 /*
2  * Copyright (c) 1983, 1989, 1993
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  * 4. 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) 1983, 1989, 1993\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[] = "@(#)renice.c	8.1 (Berkeley) 6/9/93";
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 <err.h>
50 #include <errno.h>
51 #include <limits.h>
52 #include <pwd.h>
53 #include <stdio.h>
54 #include <stdlib.h>
55 #include <string.h>
56 
57 static int	donice(int, int, int, int);
58 static int	getnum(const char *, const char *, int *);
59 static void	usage(void);
60 
61 /*
62  * Change the priority (nice) of processes
63  * or groups of processes which are already
64  * running.
65  */
66 int
67 main(int argc, char *argv[])
68 {
69 	struct passwd *pwd;
70 	int errs, incr, prio, which, who;
71 
72 	errs = 0;
73 	incr = 0;
74 	which = PRIO_PROCESS;
75 	who = 0;
76 	argc--, argv++;
77 	if (argc < 2)
78 		usage();
79 	if (strcmp(*argv, "-n") == 0) {
80 		incr = 1;
81 		argc--, argv++;
82 		if (argc < 2)
83 			usage();
84 	}
85 	if (getnum("priority", *argv, &prio))
86 		return (1);
87 	argc--, argv++;
88 	for (; argc > 0; argc--, argv++) {
89 		if (strcmp(*argv, "-g") == 0) {
90 			which = PRIO_PGRP;
91 			continue;
92 		}
93 		if (strcmp(*argv, "-u") == 0) {
94 			which = PRIO_USER;
95 			continue;
96 		}
97 		if (strcmp(*argv, "-p") == 0) {
98 			which = PRIO_PROCESS;
99 			continue;
100 		}
101 		if (which == PRIO_USER) {
102 			if ((pwd = getpwnam(*argv)) != NULL)
103 				who = pwd->pw_uid;
104 			else if (getnum("uid", *argv, &who)) {
105 				errs++;
106 				continue;
107 			} else if (who < 0) {
108 				warnx("%s: bad value", *argv);
109 				errs++;
110 				continue;
111 			}
112 		} else {
113 			if (getnum("pid", *argv, &who)) {
114 				errs++;
115 				continue;
116 			}
117 			if (who < 0) {
118 				warnx("%s: bad value", *argv);
119 				errs++;
120 				continue;
121 			}
122 		}
123 		errs += donice(which, who, prio, incr);
124 	}
125 	exit(errs != 0);
126 }
127 
128 static int
129 donice(int which, int who, int prio, int incr)
130 {
131 	int oldprio;
132 
133 	errno = 0;
134 	oldprio = getpriority(which, who);
135 	if (oldprio == -1 && errno) {
136 		warn("%d: getpriority", who);
137 		return (1);
138 	}
139 	if (incr)
140 		prio = oldprio + prio;
141 	if (prio > PRIO_MAX)
142 		prio = PRIO_MAX;
143 	if (prio < PRIO_MIN)
144 		prio = PRIO_MIN;
145 	if (setpriority(which, who, prio) < 0) {
146 		warn("%d: setpriority", who);
147 		return (1);
148 	}
149 	fprintf(stderr, "%d: old priority %d, new priority %d\n", who,
150 	    oldprio, prio);
151 	return (0);
152 }
153 
154 static int
155 getnum(const char *com, const char *str, int *val)
156 {
157 	long v;
158 	char *ep;
159 
160 	errno = 0;
161 	v = strtol(str, &ep, 10);
162 	if (v < INT_MIN || v > INT_MAX || errno == ERANGE) {
163 		warnx("%s argument %s is out of range.", com, str);
164 		return (1);
165 	}
166 	if (ep == str || *ep != '\0' || errno != 0) {
167 		warnx("Bad %s argument: %s.", com, str);
168 		return (1);
169 	}
170 
171 	*val = (int)v;
172 	return (0);
173 }
174 
175 static void
176 usage(void)
177 {
178 	fprintf(stderr, "%s\n%s\n",
179 "usage: renice priority [[-p] pid ...] [[-g] pgrp ...] [[-u] user ...]",
180 "       renice -n increment [[-p] pid ...] [[-g] pgrp ...] [[-u] user ...]");
181 	exit(1);
182 }
183