xref: /freebsd/usr.bin/renice/renice.c (revision 66fd12cf4896eb08ad8e7a2627537f84ead84dd3)
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 __FBSDID("$FreeBSD$");
46 
47 #include <sys/types.h>
48 #include <sys/time.h>
49 #include <sys/resource.h>
50 
51 #include <err.h>
52 #include <errno.h>
53 #include <limits.h>
54 #include <pwd.h>
55 #include <stdbool.h>
56 #include <stdio.h>
57 #include <stdlib.h>
58 #include <string.h>
59 
60 static int	donice(int, int, int, bool);
61 static int	getnum(const char *, const char *, int *);
62 static void	usage(void);
63 
64 /*
65  * Change the priority (nice) of processes
66  * or groups of processes which are already
67  * running.
68  */
69 int
70 main(int argc, char *argv[])
71 {
72 	struct passwd *pwd;
73 	bool havedelim = false, haveprio = false, incr = false;
74 	int errs = 0, prio = 0, who = 0, which = PRIO_PROCESS;
75 
76 	for (argc--, argv++; argc > 0; argc--, argv++) {
77 		if (!havedelim) {
78 			/* can occur at any time prior to delimiter */
79 			if (strcmp(*argv, "-g") == 0) {
80 				which = PRIO_PGRP;
81 				continue;
82 			}
83 			if (strcmp(*argv, "-u") == 0) {
84 				which = PRIO_USER;
85 				continue;
86 			}
87 			if (strcmp(*argv, "-p") == 0) {
88 				which = PRIO_PROCESS;
89 				continue;
90 			}
91 			if (strcmp(*argv, "--") == 0) {
92 				havedelim = true;
93 				continue;
94 			}
95 			if (strcmp(*argv, "-n") == 0) {
96 				/* may occur only once, prior to priority */
97 				if (haveprio || incr || argc < 2)
98 					usage();
99 				incr = true;
100 				(void)argc--, argv++;
101 				/* fall through to priority */
102 			}
103 		}
104 		if (!haveprio) {
105 			/* must occur exactly once, prior to target */
106 			if (getnum("priority", *argv, &prio))
107 				return (1);
108 			haveprio = true;
109 			continue;
110 		}
111 		if (which == PRIO_USER) {
112 			if ((pwd = getpwnam(*argv)) != NULL)
113 				who = pwd->pw_uid;
114 			else if (getnum("uid", *argv, &who)) {
115 				errs++;
116 				continue;
117 			} else if (who < 0) {
118 				warnx("%s: bad value", *argv);
119 				errs++;
120 				continue;
121 			}
122 		} else {
123 			if (getnum("pid", *argv, &who)) {
124 				errs++;
125 				continue;
126 			}
127 			if (who < 0) {
128 				warnx("%s: bad value", *argv);
129 				errs++;
130 				continue;
131 			}
132 		}
133 		errs += donice(which, who, prio, incr);
134 	}
135 	if (!haveprio)
136 		usage();
137 	exit(errs != 0);
138 }
139 
140 static int
141 donice(int which, int who, int prio, bool incr)
142 {
143 	int oldprio;
144 
145 	errno = 0;
146 	oldprio = getpriority(which, who);
147 	if (oldprio == -1 && errno) {
148 		warn("%d: getpriority", who);
149 		return (1);
150 	}
151 	if (incr)
152 		prio = oldprio + prio;
153 	if (prio > PRIO_MAX)
154 		prio = PRIO_MAX;
155 	if (prio < PRIO_MIN)
156 		prio = PRIO_MIN;
157 	if (setpriority(which, who, prio) < 0) {
158 		warn("%d: setpriority", who);
159 		return (1);
160 	}
161 	fprintf(stderr, "%d: old priority %d, new priority %d\n", who,
162 	    oldprio, prio);
163 	return (0);
164 }
165 
166 static int
167 getnum(const char *com, const char *str, int *val)
168 {
169 	long v;
170 	char *ep;
171 
172 	errno = 0;
173 	v = strtol(str, &ep, 10);
174 	if (v < INT_MIN || v > INT_MAX || errno == ERANGE) {
175 		warnx("%s argument %s is out of range.", com, str);
176 		return (1);
177 	}
178 	if (ep == str || *ep != '\0' || errno != 0) {
179 		warnx("%s argument %s is invalid.", com, str);
180 		return (1);
181 	}
182 
183 	*val = (int)v;
184 	return (0);
185 }
186 
187 static void
188 usage(void)
189 {
190 	fprintf(stderr, "%s\n%s\n",
191 "usage: renice priority [[-p] pid ...] [[-g] pgrp ...] [[-u] user ...]",
192 "       renice -n increment [[-p] pid ...] [[-g] pgrp ...] [[-u] user ...]");
193 	exit(1);
194 }
195