busybox/procps/renice.c

/* vi: set sw=4 ts=4: */
/*
 * renice implementation for busybox
 *
 * Copyright (C) 2005  Manuel Novoa III  <mjn3@codepoet.org>
 *
 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
 */

/* Notes:
 *   Setting an absolute priority was obsoleted in SUSv2 and removed
 *   in SUSv3.  However, the common linux version of renice does
 *   absolute and not relative.  So we'll continue supporting absolute,
 *   although the stdout logging has been removed since both SUSv2 and
 *   SUSv3 specify that stdout isn't used.
 *
 *   This version is lenient in that it doesn't require any IDs.  The
 *   options -p, -g, and -u are treated as mode switches for the
 *   following IDs (if any).  Multiple switches are allowed.
 */

#include "busybox.h"
#include <sys/resource.h>

void BUG_bad_PRIO_PROCESS(void);
void BUG_bad_PRIO_PGRP(void);
void BUG_bad_PRIO_USER(void);

int renice_main(int argc, char **argv)
{
	static const char Xetpriority_msg[] = "%cetpriority";

	int retval = EXIT_SUCCESS;
	int which = PRIO_PROCESS;	/* Default 'which' value. */
	int use_relative = 0;
	int adjustment, new_priority;
	unsigned who;
	char *arg;

	/* Yes, they are not #defines in glibc 2.4! #if won't work */
	if (PRIO_PROCESS < CHAR_MIN || PRIO_PROCESS > CHAR_MAX)
		BUG_bad_PRIO_PROCESS();
	if (PRIO_PGRP < CHAR_MIN || PRIO_PGRP > CHAR_MAX)
		BUG_bad_PRIO_PGRP();
	if (PRIO_USER < CHAR_MIN || PRIO_USER > CHAR_MAX)
		BUG_bad_PRIO_USER();

	arg = *++argv;

	/* Check if we are using a relative adjustment. */
	if (arg && arg[0] == '-' && arg[1] == 'n') {
		use_relative = 1;
		if (!arg[2])
			arg = *++argv;
		else
			arg += 2;
	}

	if (!arg) {				/* No args?  Then show usage. */
		bb_show_usage();
	}

	/* Get the priority adjustment (absolute or relative). */
	adjustment = xatoi_range(arg, INT_MIN/2, INT_MAX/2);

	while ((arg = *++argv) != NULL) {
		/* Check for a mode switch. */
		if (arg[0] == '-' && arg[1]) {
			static const char opts[]
				= { 'p', 'g', 'u', 0, PRIO_PROCESS, PRIO_PGRP, PRIO_USER };
			const char *p = strchr(opts, arg[1]);
			if (p) {
				which = p[4];
				if (!arg[2])
					continue;
				arg += 2;
			}
		}

		/* Process an ID arg. */
		if (which == PRIO_USER) {
			struct passwd *p;
			p = getpwnam(arg);
			if (!p) {
				bb_error_msg("unknown user: %s", arg);
				goto HAD_ERROR;
			}
			who = p->pw_uid;
		} else {
			who = bb_strtou(arg, NULL, 10);
			if (errno) {
				bb_error_msg("bad value: %s", arg);
				goto HAD_ERROR;
			}
		}

		/* Get priority to use, and set it. */
		if (use_relative) {
			int old_priority;

			errno = 0;	 /* Needed for getpriority error detection. */
			old_priority = getpriority(which, who);
			if (errno) {
				bb_perror_msg(Xetpriority_msg, 'g');
				goto HAD_ERROR;
			}

			new_priority = old_priority + adjustment;
		} else {
			new_priority = adjustment;
		}

		if (setpriority(which, who, new_priority) == 0) {
			continue;
		}

		bb_perror_msg(Xetpriority_msg, 's');
 HAD_ERROR:
		retval = EXIT_FAILURE;
	}

	/* No need to check for errors outputing to stderr since, if it
	 * was used, the HAD_ERROR label was reached and retval was set. */

	return retval;
}
1	/* vi: set sw=4 ts=4: */
2	/*
3	* renice implementation for busybox
4	*
5	* Copyright (C) 2005 Manuel Novoa III <mjn3@codepoet.org>
6	*
7	* Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
8	*/
9
10	/* Notes:
11	* Setting an absolute priority was obsoleted in SUSv2 and removed
12	* in SUSv3. However, the common linux version of renice does
13	* absolute and not relative. So we'll continue supporting absolute,
14	* although the stdout logging has been removed since both SUSv2 and
15	* SUSv3 specify that stdout isn't used.
16	*
17	* This version is lenient in that it doesn't require any IDs. The
18	* options -p, -g, and -u are treated as mode switches for the
19	* following IDs (if any). Multiple switches are allowed.
20	*/
21
22	#include "busybox.h"
23	#include <sys/resource.h>
24
25	void BUG_bad_PRIO_PROCESS(void);
26	void BUG_bad_PRIO_PGRP(void);
27	void BUG_bad_PRIO_USER(void);
28
29	int renice_main(int argc, char **argv)
30	{
31	static const char Xetpriority_msg[] = "%cetpriority";
32
33	int retval = EXIT_SUCCESS;
34	int which = PRIO_PROCESS; /* Default 'which' value. */
35	int use_relative = 0;
36	int adjustment, new_priority;
37	unsigned who;
38	char *arg;
39
40	/* Yes, they are not #defines in glibc 2.4! #if won't work */
41	if (PRIO_PROCESS < CHAR_MIN \|\| PRIO_PROCESS > CHAR_MAX)
42	BUG_bad_PRIO_PROCESS();
43	if (PRIO_PGRP < CHAR_MIN \|\| PRIO_PGRP > CHAR_MAX)
44	BUG_bad_PRIO_PGRP();
45	if (PRIO_USER < CHAR_MIN \|\| PRIO_USER > CHAR_MAX)
46	BUG_bad_PRIO_USER();
47
48	arg = *++argv;
49
50	/* Check if we are using a relative adjustment. */
51	if (arg && arg[0] == '-' && arg[1] == 'n') {
52	use_relative = 1;
53	if (!arg[2])
54	arg = *++argv;
55	else
56	arg += 2;
57	}
58
59	if (!arg) { /* No args? Then show usage. */
60	bb_show_usage();
61	}
62
63	/* Get the priority adjustment (absolute or relative). */
64	adjustment = xatoi_range(arg, INT_MIN/2, INT_MAX/2);
65
66	while ((arg = *++argv) != NULL) {
67	/* Check for a mode switch. */
68	if (arg[0] == '-' && arg[1]) {
69	static const char opts[]
70	= { 'p', 'g', 'u', 0, PRIO_PROCESS, PRIO_PGRP, PRIO_USER };
71	const char *p = strchr(opts, arg[1]);
72	if (p) {
73	which = p[4];
74	if (!arg[2])
75	continue;
76	arg += 2;
77	}
78	}
79
80	/* Process an ID arg. */
81	if (which == PRIO_USER) {
82	struct passwd *p;
83	p = getpwnam(arg);
84	if (!p) {
85	bb_error_msg("unknown user: %s", arg);
86	goto HAD_ERROR;
87	}
88	who = p->pw_uid;
89	} else {
90	who = bb_strtou(arg, NULL, 10);
91	if (errno) {
92	bb_error_msg("bad value: %s", arg);
93	goto HAD_ERROR;
94	}
95	}
96
97	/* Get priority to use, and set it. */
98	if (use_relative) {
99	int old_priority;
100
101	errno = 0; /* Needed for getpriority error detection. */
102	old_priority = getpriority(which, who);
103	if (errno) {
104	bb_perror_msg(Xetpriority_msg, 'g');
105	goto HAD_ERROR;
106	}
107
108	new_priority = old_priority + adjustment;
109	} else {
110	new_priority = adjustment;
111	}
112
113	if (setpriority(which, who, new_priority) == 0) {
114	continue;
115	}
116
117	bb_perror_msg(Xetpriority_msg, 's');
118	HAD_ERROR:
119	retval = EXIT_FAILURE;
120	}
121
122	/* No need to check for errors outputing to stderr since, if it
123	* was used, the HAD_ERROR label was reached and retval was set. */
124
125	return retval;
126	}