xref: /freebsd/usr.bin/renice/renice.c (revision 734e82fe33aa764367791a7d603b383996c6b40b)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
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 #ifndef lint
33 static const char copyright[] =
34 "@(#) Copyright (c) 1983, 1989, 1993\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[] = "@(#)renice.c	8.1 (Berkeley) 6/9/93";
41 #endif /* not lint */
42 #endif
43 
44 #include <sys/cdefs.h>
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 <stdbool.h>
54 #include <stdio.h>
55 #include <stdlib.h>
56 #include <string.h>
57 
58 static int	donice(int, int, int, bool);
59 static int	getnum(const char *, const char *, int *);
60 static void	usage(void);
61 
62 /*
63  * Change the priority (nice) of processes
64  * or groups of processes which are already
65  * running.
66  */
67 int
68 main(int argc, char *argv[])
69 {
70 	struct passwd *pwd;
71 	bool havedelim = false, haveprio = false, incr = false;
72 	int errs = 0, prio = 0, who = 0, which = PRIO_PROCESS;
73 
74 	for (argc--, argv++; argc > 0; argc--, argv++) {
75 		if (!havedelim) {
76 			/* can occur at any time prior to delimiter */
77 			if (strcmp(*argv, "-g") == 0) {
78 				which = PRIO_PGRP;
79 				continue;
80 			}
81 			if (strcmp(*argv, "-u") == 0) {
82 				which = PRIO_USER;
83 				continue;
84 			}
85 			if (strcmp(*argv, "-p") == 0) {
86 				which = PRIO_PROCESS;
87 				continue;
88 			}
89 			if (strcmp(*argv, "--") == 0) {
90 				havedelim = true;
91 				continue;
92 			}
93 			if (strcmp(*argv, "-n") == 0) {
94 				/* may occur only once, prior to priority */
95 				if (haveprio || incr || argc < 2)
96 					usage();
97 				incr = true;
98 				(void)argc--, argv++;
99 				/* fall through to priority */
100 			}
101 		}
102 		if (!haveprio) {
103 			/* must occur exactly once, prior to target */
104 			if (getnum("priority", *argv, &prio))
105 				return (1);
106 			haveprio = true;
107 			continue;
108 		}
109 		if (which == PRIO_USER) {
110 			if ((pwd = getpwnam(*argv)) != NULL)
111 				who = pwd->pw_uid;
112 			else if (getnum("uid", *argv, &who)) {
113 				errs++;
114 				continue;
115 			} else if (who < 0) {
116 				warnx("%s: bad value", *argv);
117 				errs++;
118 				continue;
119 			}
120 		} else {
121 			if (getnum("pid", *argv, &who)) {
122 				errs++;
123 				continue;
124 			}
125 			if (who < 0) {
126 				warnx("%s: bad value", *argv);
127 				errs++;
128 				continue;
129 			}
130 		}
131 		errs += donice(which, who, prio, incr);
132 	}
133 	if (!haveprio)
134 		usage();
135 	exit(errs != 0);
136 }
137 
138 static int
139 donice(int which, int who, int prio, bool incr)
140 {
141 	int oldprio;
142 
143 	errno = 0;
144 	oldprio = getpriority(which, who);
145 	if (oldprio == -1 && errno) {
146 		warn("%d: getpriority", who);
147 		return (1);
148 	}
149 	if (incr)
150 		prio = oldprio + prio;
151 	if (prio > PRIO_MAX)
152 		prio = PRIO_MAX;
153 	if (prio < PRIO_MIN)
154 		prio = PRIO_MIN;
155 	if (setpriority(which, who, prio) < 0) {
156 		warn("%d: setpriority", who);
157 		return (1);
158 	}
159 	fprintf(stderr, "%d: old priority %d, new priority %d\n", who,
160 	    oldprio, prio);
161 	return (0);
162 }
163 
164 static int
165 getnum(const char *com, const char *str, int *val)
166 {
167 	long v;
168 	char *ep;
169 
170 	errno = 0;
171 	v = strtol(str, &ep, 10);
172 	if (v < INT_MIN || v > INT_MAX || errno == ERANGE) {
173 		warnx("%s argument %s is out of range.", com, str);
174 		return (1);
175 	}
176 	if (ep == str || *ep != '\0' || errno != 0) {
177 		warnx("%s argument %s is invalid.", com, str);
178 		return (1);
179 	}
180 
181 	*val = (int)v;
182 	return (0);
183 }
184 
185 static void
186 usage(void)
187 {
188 	fprintf(stderr, "%s\n%s\n",
189 "usage: renice priority [[-p] pid ...] [[-g] pgrp ...] [[-u] user ...]",
190 "       renice -n increment [[-p] pid ...] [[-g] pgrp ...] [[-u] user ...]");
191 	exit(1);
192 }
193