xref: /netbsd-src/usr.bin/renice/renice.c (revision e2f11738e521c21ecf1e9ca32c6e71e1af017242)
1 /*	$NetBSD: renice.c,v 1.20 2020/10/23 16:16:10 wiz Exp $	*/
2 
3 /*
4  * Copyright (c) 1983, 1989, 1993
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 #include <sys/cdefs.h>
33 #ifndef lint
34 __COPYRIGHT("@(#) Copyright (c) 1983, 1989, 1993\
35  The Regents of the University of California.  All rights reserved.");
36 #endif /* not lint */
37 
38 #ifndef lint
39 /*static char sccsid[] = "from: @(#)renice.c	8.1 (Berkeley) 6/9/93";*/
40 __RCSID("$NetBSD: renice.c,v 1.20 2020/10/23 16:16:10 wiz Exp $");
41 #endif /* not lint */
42 
43 #include <sys/resource.h>
44 
45 #include <err.h>
46 #include <errno.h>
47 #include <limits.h>
48 #include <pwd.h>
49 #include <stdio.h>
50 #include <stdlib.h>
51 #include <string.h>
52 #include <sysexits.h>
53 
54 static int	getnum(const char *, const char *, int *);
55 static int	donice(int, id_t, int, int);
56 static void	usage(void) __dead;
57 
58 /*
59  * Change the priority (nice) of processes
60  * or groups of processes which are already
61  * running.
62  */
63 int
main(int argc,char ** argv)64 main(int argc, char **argv)
65 {
66 	int which = PRIO_PROCESS;
67 	int prio, errs = 0, incr = 0;
68 	id_t who = 0;
69 
70 	argc--, argv++;
71 	if (argc < 2)
72 		usage();
73 	if (strcmp(*argv, "-n") == 0) {
74 		incr = 1;
75 		argc--, argv++;
76 		if (argc < 2)
77 			usage();
78 	}
79 	if (getnum("priority", *argv, &prio))
80 		return 1;
81 	argc--, argv++;
82 	for (; argc > 0; argc--, argv++) {
83 		if (strcmp(*argv, "-g") == 0) {
84 			which = PRIO_PGRP;
85 			continue;
86 		}
87 		if (strcmp(*argv, "-u") == 0) {
88 			which = PRIO_USER;
89 			continue;
90 		}
91 		if (strcmp(*argv, "-p") == 0) {
92 			which = PRIO_PROCESS;
93 			continue;
94 		}
95 		if (which == PRIO_USER) {
96 			struct passwd *pwd = getpwnam(*argv);
97 
98 			if (pwd == NULL) {
99 				warnx("%s: unknown user", *argv);
100 				errs++;
101 				continue;
102 			}
103 			who = (id_t)pwd->pw_uid;
104 		} else {
105 			int twho;
106 			if (getnum("pid", *argv, &twho)) {
107 				errs++;
108 				continue;
109 			}
110 			if (twho < 0) {
111 				warnx("%s: bad value", *argv);
112 				errs++;
113 				continue;
114 			}
115 			who = (id_t)twho;
116 		}
117 		errs += donice(which, who, prio, incr);
118 	}
119 	return errs == 0 ? EXIT_SUCCESS : EXIT_FAILURE;
120 }
121 
122 static int
getnum(const char * com,const char * str,int * val)123 getnum(const char *com, const char *str, int *val)
124 {
125 	long v;
126 	char *ep;
127 
128 	errno = 0;
129 	v = strtol(str, &ep, 0);
130 
131 	if (*ep) {
132 		warnx("Bad %s argument: %s", com, str);
133 		return 1;
134 	}
135 	if ((v == LONG_MIN || v == LONG_MAX) && errno == ERANGE) {
136 		warn("Invalid %s argument: %s", com, str);
137 		return 1;
138 	}
139 
140 	*val = (int)v;
141 	return 0;
142 }
143 
144 static int
donice(int which,id_t who,int prio,int incr)145 donice(int which, id_t who, int prio, int incr)
146 {
147 	int oldprio;
148 
149 	errno = 0;
150 	if ((oldprio = getpriority(which, who)) == -1 && errno != 0) {
151 		warn("%d: getpriority", who);
152 		return 1;
153 	}
154 
155 	if (incr)
156 		prio = oldprio + prio;
157 
158 	if (prio > PRIO_MAX)
159 		prio = PRIO_MAX;
160 	if (prio < PRIO_MIN)
161 		prio = PRIO_MIN;
162 
163 	if (setpriority(which, who, prio) == -1) {
164 		warn("%d: setpriority", who);
165 		return 1;
166 	}
167 	(void)printf("%d: old priority %d, new priority %d\n",
168 	    who, oldprio, prio);
169 	return 0;
170 }
171 
172 static void
usage(void)173 usage(void)
174 {
175 
176 	(void)fprintf(stderr, "Usage: %s [<priority> | -n <incr>] ",
177 	    getprogname());
178 	(void)fprintf(stderr, "[[-gpu] who ...] ...\n");
179 	exit(1);
180 }
181