xref: /freebsd/usr.bin/renice/renice.c (revision d37eb51047221dc3322b34db1038ff3aa533883f)
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 #include <sys/types.h>
33 #include <sys/time.h>
34 #include <sys/resource.h>
35 
36 #include <err.h>
37 #include <errno.h>
38 #include <limits.h>
39 #include <pwd.h>
40 #include <stdbool.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 
45 static int	donice(int, int, int, bool);
46 static int	getnum(const char *, const char *, int *);
47 static void	usage(void);
48 
49 /*
50  * Change the priority (nice) of processes
51  * or groups of processes which are already
52  * running.
53  */
54 int
55 main(int argc, char *argv[])
56 {
57 	struct passwd *pwd;
58 	bool havedelim = false, haveprio = false, incr = false;
59 	int errs = 0, prio = 0, who = 0, which = PRIO_PROCESS;
60 
61 	for (argc--, argv++; argc > 0; argc--, argv++) {
62 		if (!havedelim) {
63 			/* can occur at any time prior to delimiter */
64 			if (strcmp(*argv, "-g") == 0) {
65 				which = PRIO_PGRP;
66 				continue;
67 			}
68 			if (strcmp(*argv, "-u") == 0) {
69 				which = PRIO_USER;
70 				continue;
71 			}
72 			if (strcmp(*argv, "-p") == 0) {
73 				which = PRIO_PROCESS;
74 				continue;
75 			}
76 			if (strcmp(*argv, "--") == 0) {
77 				havedelim = true;
78 				continue;
79 			}
80 			if (strcmp(*argv, "-n") == 0) {
81 				/* may occur only once, prior to priority */
82 				if (haveprio || incr || argc < 2)
83 					usage();
84 				incr = true;
85 				(void)argc--, argv++;
86 				/* fall through to priority */
87 			}
88 		}
89 		if (!haveprio) {
90 			/* must occur exactly once, prior to target */
91 			if (getnum("priority", *argv, &prio))
92 				return (1);
93 			haveprio = true;
94 			continue;
95 		}
96 		if (which == PRIO_USER) {
97 			if ((pwd = getpwnam(*argv)) != NULL)
98 				who = pwd->pw_uid;
99 			else if (getnum("uid", *argv, &who)) {
100 				errs++;
101 				continue;
102 			} else if (who < 0) {
103 				warnx("%s: bad value", *argv);
104 				errs++;
105 				continue;
106 			}
107 		} else {
108 			if (getnum("pid", *argv, &who)) {
109 				errs++;
110 				continue;
111 			}
112 			if (who < 0) {
113 				warnx("%s: bad value", *argv);
114 				errs++;
115 				continue;
116 			}
117 		}
118 		errs += donice(which, who, prio, incr);
119 	}
120 	if (!haveprio)
121 		usage();
122 	exit(errs != 0);
123 }
124 
125 static int
126 donice(int which, int who, int prio, bool incr)
127 {
128 	int oldprio;
129 
130 	errno = 0;
131 	oldprio = getpriority(which, who);
132 	if (oldprio == -1 && errno) {
133 		warn("%d: getpriority", who);
134 		return (1);
135 	}
136 	if (incr)
137 		prio = oldprio + prio;
138 	if (prio > PRIO_MAX)
139 		prio = PRIO_MAX;
140 	if (prio < PRIO_MIN)
141 		prio = PRIO_MIN;
142 	if (setpriority(which, who, prio) < 0) {
143 		warn("%d: setpriority", who);
144 		return (1);
145 	}
146 	fprintf(stderr, "%d: old priority %d, new priority %d\n", who,
147 	    oldprio, prio);
148 	return (0);
149 }
150 
151 static int
152 getnum(const char *com, const char *str, int *val)
153 {
154 	long v;
155 	char *ep;
156 
157 	errno = 0;
158 	v = strtol(str, &ep, 10);
159 	if (v < INT_MIN || v > INT_MAX || errno == ERANGE) {
160 		warnx("%s argument %s is out of range.", com, str);
161 		return (1);
162 	}
163 	if (ep == str || *ep != '\0' || errno != 0) {
164 		warnx("%s argument %s is invalid.", com, str);
165 		return (1);
166 	}
167 
168 	*val = (int)v;
169 	return (0);
170 }
171 
172 static void
173 usage(void)
174 {
175 	fprintf(stderr, "%s\n%s\n",
176 "usage: renice priority [[-p] pid ...] [[-g] pgrp ...] [[-u] user ...]",
177 "       renice -n increment [[-p] pid ...] [[-g] pgrp ...] [[-u] user ...]");
178 	exit(1);
179 }
180