xref: /freebsd/usr.bin/renice/renice.c (revision bdcbfde31e8e9b343f113a1956384bdf30d1ed62)
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 #endif
40 
41 #include <sys/cdefs.h>
42 #include <sys/types.h>
43 #include <sys/time.h>
44 #include <sys/resource.h>
45 
46 #include <err.h>
47 #include <errno.h>
48 #include <limits.h>
49 #include <pwd.h>
50 #include <stdbool.h>
51 #include <stdio.h>
52 #include <stdlib.h>
53 #include <string.h>
54 
55 static int	donice(int, int, int, bool);
56 static int	getnum(const char *, const char *, int *);
57 static void	usage(void);
58 
59 /*
60  * Change the priority (nice) of processes
61  * or groups of processes which are already
62  * running.
63  */
64 int
65 main(int argc, char *argv[])
66 {
67 	struct passwd *pwd;
68 	bool havedelim = false, haveprio = false, incr = false;
69 	int errs = 0, prio = 0, who = 0, which = PRIO_PROCESS;
70 
71 	for (argc--, argv++; argc > 0; argc--, argv++) {
72 		if (!havedelim) {
73 			/* can occur at any time prior to delimiter */
74 			if (strcmp(*argv, "-g") == 0) {
75 				which = PRIO_PGRP;
76 				continue;
77 			}
78 			if (strcmp(*argv, "-u") == 0) {
79 				which = PRIO_USER;
80 				continue;
81 			}
82 			if (strcmp(*argv, "-p") == 0) {
83 				which = PRIO_PROCESS;
84 				continue;
85 			}
86 			if (strcmp(*argv, "--") == 0) {
87 				havedelim = true;
88 				continue;
89 			}
90 			if (strcmp(*argv, "-n") == 0) {
91 				/* may occur only once, prior to priority */
92 				if (haveprio || incr || argc < 2)
93 					usage();
94 				incr = true;
95 				(void)argc--, argv++;
96 				/* fall through to priority */
97 			}
98 		}
99 		if (!haveprio) {
100 			/* must occur exactly once, prior to target */
101 			if (getnum("priority", *argv, &prio))
102 				return (1);
103 			haveprio = true;
104 			continue;
105 		}
106 		if (which == PRIO_USER) {
107 			if ((pwd = getpwnam(*argv)) != NULL)
108 				who = pwd->pw_uid;
109 			else if (getnum("uid", *argv, &who)) {
110 				errs++;
111 				continue;
112 			} else if (who < 0) {
113 				warnx("%s: bad value", *argv);
114 				errs++;
115 				continue;
116 			}
117 		} else {
118 			if (getnum("pid", *argv, &who)) {
119 				errs++;
120 				continue;
121 			}
122 			if (who < 0) {
123 				warnx("%s: bad value", *argv);
124 				errs++;
125 				continue;
126 			}
127 		}
128 		errs += donice(which, who, prio, incr);
129 	}
130 	if (!haveprio)
131 		usage();
132 	exit(errs != 0);
133 }
134 
135 static int
136 donice(int which, int who, int prio, bool incr)
137 {
138 	int oldprio;
139 
140 	errno = 0;
141 	oldprio = getpriority(which, who);
142 	if (oldprio == -1 && errno) {
143 		warn("%d: getpriority", who);
144 		return (1);
145 	}
146 	if (incr)
147 		prio = oldprio + prio;
148 	if (prio > PRIO_MAX)
149 		prio = PRIO_MAX;
150 	if (prio < PRIO_MIN)
151 		prio = PRIO_MIN;
152 	if (setpriority(which, who, prio) < 0) {
153 		warn("%d: setpriority", who);
154 		return (1);
155 	}
156 	fprintf(stderr, "%d: old priority %d, new priority %d\n", who,
157 	    oldprio, prio);
158 	return (0);
159 }
160 
161 static int
162 getnum(const char *com, const char *str, int *val)
163 {
164 	long v;
165 	char *ep;
166 
167 	errno = 0;
168 	v = strtol(str, &ep, 10);
169 	if (v < INT_MIN || v > INT_MAX || errno == ERANGE) {
170 		warnx("%s argument %s is out of range.", com, str);
171 		return (1);
172 	}
173 	if (ep == str || *ep != '\0' || errno != 0) {
174 		warnx("%s argument %s is invalid.", com, str);
175 		return (1);
176 	}
177 
178 	*val = (int)v;
179 	return (0);
180 }
181 
182 static void
183 usage(void)
184 {
185 	fprintf(stderr, "%s\n%s\n",
186 "usage: renice priority [[-p] pid ...] [[-g] pgrp ...] [[-u] user ...]",
187 "       renice -n increment [[-p] pid ...] [[-g] pgrp ...] [[-u] user ...]");
188 	exit(1);
189 }
190