xref: /netbsd-src/usr.bin/getconf/getconf.c (revision a95481fd2f1bf907746f14cdcc9ee8a738e7563f)
1 /*	$NetBSD: getconf.c,v 1.38 2024/07/22 21:03:17 rillig Exp $	*/
2 
3 /*-
4  * Copyright (c) 1996, 1998 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by J.T. Conklin.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 __RCSID("$NetBSD: getconf.c,v 1.38 2024/07/22 21:03:17 rillig Exp $");
34 
35 #include <err.h>
36 #include <errno.h>
37 #include <limits.h>
38 #include <locale.h>
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <unistd.h>
42 #include <string.h>
43 
44 struct conf_variable
45 {
46   const char *name;
47   enum { SYSCONF, CONFSTR, PATHCONF, CONSTANT } type;
48   long value;
49 };
50 
51 static void print_longvar(const char *, long);
52 static void print_strvar(const char *, const char *);
53 static void printvar(const struct conf_variable *, const char *);
54 static void usage(void) __dead;
55 
56 static const struct conf_variable conf_table[] =
57 {
58   { "PATH",			CONFSTR,	_CS_PATH		},
59 
60   /* Utility Limit Minimum Values */
61   { "POSIX2_BC_BASE_MAX",	CONSTANT,	_POSIX2_BC_BASE_MAX	},
62   { "POSIX2_BC_DIM_MAX",	CONSTANT,	_POSIX2_BC_DIM_MAX	},
63   { "POSIX2_BC_SCALE_MAX",	CONSTANT,	_POSIX2_BC_SCALE_MAX	},
64   { "POSIX2_BC_STRING_MAX",	CONSTANT,	_POSIX2_BC_STRING_MAX	},
65   { "POSIX2_COLL_WEIGHTS_MAX",	CONSTANT,	_POSIX2_COLL_WEIGHTS_MAX },
66   { "POSIX2_EXPR_NEST_MAX",	CONSTANT,	_POSIX2_EXPR_NEST_MAX	},
67   { "POSIX2_LINE_MAX",		CONSTANT,	_POSIX2_LINE_MAX	},
68   { "POSIX2_RE_DUP_MAX",	CONSTANT,	_POSIX2_RE_DUP_MAX	},
69   { "POSIX2_VERSION",		CONSTANT,	_POSIX2_VERSION		},
70 
71   /* POSIX.1 Minimum Values */
72   { "_POSIX_AIO_LISTIO_MAX",	CONSTANT,	_POSIX_AIO_LISTIO_MAX	},
73   { "_POSIX_AIO_MAX",		CONSTANT,       _POSIX_AIO_MAX		},
74   { "_POSIX_ARG_MAX",		CONSTANT,	_POSIX_ARG_MAX		},
75   { "_POSIX_CHILD_MAX",		CONSTANT,	_POSIX_CHILD_MAX	},
76   { "_POSIX_LINK_MAX",		CONSTANT,	_POSIX_LINK_MAX		},
77   { "_POSIX_MAX_CANON",		CONSTANT,	_POSIX_MAX_CANON	},
78   { "_POSIX_MAX_INPUT",		CONSTANT,	_POSIX_MAX_INPUT	},
79   { "_POSIX_MQ_OPEN_MAX",	CONSTANT,	_POSIX_MQ_OPEN_MAX	},
80   { "_POSIX_MQ_PRIO_MAX",	CONSTANT,	_POSIX_MQ_PRIO_MAX	},
81   { "_POSIX_NAME_MAX",		CONSTANT,	_POSIX_NAME_MAX		},
82   { "_POSIX_NGROUPS_MAX",	CONSTANT,	_POSIX_NGROUPS_MAX	},
83   { "_POSIX_OPEN_MAX",		CONSTANT,	_POSIX_OPEN_MAX		},
84   { "_POSIX_PATH_MAX",		CONSTANT,	_POSIX_PATH_MAX		},
85   { "_POSIX_PIPE_BUF",		CONSTANT,	_POSIX_PIPE_BUF		},
86   { "_POSIX_SSIZE_MAX",		CONSTANT,	_POSIX_SSIZE_MAX	},
87   { "_POSIX_STREAM_MAX",	CONSTANT,	_POSIX_STREAM_MAX	},
88   { "_POSIX_TZNAME_MAX",	CONSTANT,	_POSIX_TZNAME_MAX	},
89 
90   /* Symbolic Utility Limits */
91   { "BC_BASE_MAX",		SYSCONF,	_SC_BC_BASE_MAX		},
92   { "BC_DIM_MAX",		SYSCONF,	_SC_BC_DIM_MAX		},
93   { "BC_SCALE_MAX",		SYSCONF,	_SC_BC_SCALE_MAX	},
94   { "BC_STRING_MAX",		SYSCONF,	_SC_BC_STRING_MAX	},
95   { "COLL_WEIGHTS_MAX",		SYSCONF,	_SC_COLL_WEIGHTS_MAX	},
96   { "EXPR_NEST_MAX",		SYSCONF,	_SC_EXPR_NEST_MAX	},
97   { "LINE_MAX",			SYSCONF,	_SC_LINE_MAX		},
98   { "RE_DUP_MAX",		SYSCONF,	_SC_RE_DUP_MAX		},
99 
100   /* Optional Facility Configuration Values */
101   { "_POSIX2_C_BIND",		SYSCONF,	_SC_2_C_BIND		},
102   { "POSIX2_C_DEV",		SYSCONF,	_SC_2_C_DEV		},
103   { "POSIX2_CHAR_TERM",		SYSCONF,	_SC_2_CHAR_TERM		},
104   { "POSIX2_FORT_DEV",		SYSCONF,	_SC_2_FORT_DEV		},
105   { "POSIX2_FORT_RUN",		SYSCONF,	_SC_2_FORT_RUN		},
106   { "POSIX2_LOCALEDEF",		SYSCONF,	_SC_2_LOCALEDEF		},
107   { "POSIX2_SW_DEV",		SYSCONF,	_SC_2_SW_DEV		},
108   { "POSIX2_UPE",		SYSCONF,	_SC_2_UPE		},
109 
110   /* POSIX.1 Configurable System Variables */
111   { "AIO_LISTIO_MAX",		SYSCONF,	_SC_AIO_LISTIO_MAX	},
112   { "AIO_MAX",			SYSCONF,	_SC_AIO_MAX		},
113   { "ARG_MAX",			SYSCONF,	_SC_ARG_MAX 		},
114   { "CHILD_MAX",		SYSCONF,	_SC_CHILD_MAX		},
115   { "CLK_TCK",			SYSCONF,	_SC_CLK_TCK		},
116   { "MQ_OPEN_MAX",		SYSCONF,	_SC_MQ_OPEN_MAX		},
117   { "MQ_PRIO_MAX",		SYSCONF,	_SC_MQ_PRIO_MAX		},
118   { "NGROUPS_MAX",		SYSCONF,	_SC_NGROUPS_MAX		},
119   { "OPEN_MAX",			SYSCONF,	_SC_OPEN_MAX		},
120   { "STREAM_MAX",		SYSCONF,	_SC_STREAM_MAX		},
121   { "TZNAME_MAX",		SYSCONF,	_SC_TZNAME_MAX		},
122   { "_POSIX_JOB_CONTROL",	SYSCONF,	_SC_JOB_CONTROL 	},
123   { "_POSIX_SAVED_IDS",		SYSCONF,	_SC_SAVED_IDS		},
124   { "_POSIX_VERSION",		SYSCONF,	_SC_VERSION		},
125 
126   { "LINK_MAX",			PATHCONF,	_PC_LINK_MAX		},
127   { "MAX_CANON",		PATHCONF,	_PC_MAX_CANON		},
128   { "MAX_INPUT",		PATHCONF,	_PC_MAX_INPUT		},
129   { "NAME_MAX",			PATHCONF,	_PC_NAME_MAX		},
130   { "PATH_MAX",			PATHCONF,	_PC_PATH_MAX		},
131   { "PIPE_BUF",			PATHCONF,	_PC_PIPE_BUF		},
132   { "_POSIX_CHOWN_RESTRICTED",	PATHCONF,	_PC_CHOWN_RESTRICTED	},
133   { "_POSIX_NO_TRUNC",		PATHCONF,	_PC_NO_TRUNC		},
134   { "_POSIX_VDISABLE",		PATHCONF,	_PC_VDISABLE		},
135 
136   /* POSIX.1b Configurable System Variables */
137   { "PAGESIZE",			SYSCONF,	_SC_PAGESIZE		},
138   { "_POSIX_ASYNCHRONOUS_IO",	SYSCONF,	_SC_ASYNCHRONOUS_IO	},
139   { "_POSIX_FSYNC",		SYSCONF,	_SC_FSYNC		},
140   { "_POSIX_MAPPED_FILES",	SYSCONF,	_SC_MAPPED_FILES	},
141   { "_POSIX_MEMLOCK",		SYSCONF,	_SC_MEMLOCK		},
142   { "_POSIX_MEMLOCK_RANGE",	SYSCONF,	_SC_MEMLOCK_RANGE	},
143   { "_POSIX_MEMORY_PROTECTION",	SYSCONF,	_SC_MEMORY_PROTECTION	},
144   { "_POSIX_MESSAGE_PASSING",	SYSCONF,	_SC_MESSAGE_PASSING	},
145   { "_POSIX_MONOTONIC_CLOCK",	SYSCONF,	_SC_MONOTONIC_CLOCK	},
146   { "_POSIX_PRIORITY_SCHEDULING", SYSCONF,	_SC_PRIORITY_SCHEDULING },
147   { "_POSIX_SEMAPHORES",	SYSCONF,	_SC_SEMAPHORES		},
148   { "_POSIX_SHARED_MEMORY_OBJECTS", SYSCONF,	_SC_SHARED_MEMORY_OBJECTS },
149   { "_POSIX_SYNCHRONIZED_IO",	SYSCONF,	_SC_SYNCHRONIZED_IO	},
150   { "_POSIX_TIMERS",		SYSCONF,	_SC_TIMERS		},
151 
152   { "_POSIX_SYNC_IO",		PATHCONF,	_PC_SYNC_IO		},
153 
154   /* POSIX.1c Configurable System Variables */
155   { "LOGIN_NAME_MAX",		SYSCONF,	_SC_LOGIN_NAME_MAX	},
156   { "_POSIX_THREADS",		SYSCONF,	_SC_THREADS		},
157 
158   /* POSIX.1j Configurable System Variables */
159   { "_POSIX_BARRIERS",		SYSCONF,	_SC_BARRIERS		},
160   { "_POSIX_READER_WRITER_LOCKS", SYSCONF,	_SC_READER_WRITER_LOCKS	},
161   { "_POSIX_SPIN_LOCKS",	SYSCONF,	_SC_SPIN_LOCKS		},
162 
163   /* XPG4.2 Configurable System Variables */
164   { "IOV_MAX",			SYSCONF,	_SC_IOV_MAX		},
165   { "PAGE_SIZE",		SYSCONF,	_SC_PAGE_SIZE		},
166   { "_XOPEN_SHM",		SYSCONF,	_SC_XOPEN_SHM		},
167 
168   /* X/Open CAE Spec. Issue 5 Version 2 Configurable System Variables */
169   { "FILESIZEBITS",		PATHCONF,	_PC_FILESIZEBITS	},
170 
171   /* POSIX.1-2001 XSI Option Group Configurable System Variables */
172   { "ATEXIT_MAX",		SYSCONF,	_SC_ATEXIT_MAX		},
173 
174   /* POSIX.1-2001 TSF Configurable System Variables */
175   { "GETGR_R_SIZE_MAX",		SYSCONF,	_SC_GETGR_R_SIZE_MAX	},
176   { "GETPW_R_SIZE_MAX",		SYSCONF,	_SC_GETPW_R_SIZE_MAX	},
177 
178   /* Extensions found in Solaris and Linux. */
179   { "SC_PHYS_PAGES",		SYSCONF,	_SC_PHYS_PAGES		},
180   { "SC_AVPHYS_PAGES",		SYSCONF,	_SC_AVPHYS_PAGES	},
181 
182 #ifdef _NETBSD_SOURCE
183   /* Commonly provided extensions */
184   { "NPROCESSORS_CONF",		SYSCONF,	_SC_NPROCESSORS_CONF	},
185   { "NPROCESSORS_ONLN",		SYSCONF,	_SC_NPROCESSORS_ONLN	},
186 #endif	/* _NETBSD_SOURCE */
187 
188   { NULL, CONSTANT, 0L }
189 };
190 
191 static int a_flag = 0;		/* list all variables */
192 
193 int
194 main(int argc, char **argv)
195 {
196 	int ch;
197 	const struct conf_variable *cp;
198 	const char *varname, *pathname, *vn;
199 	int found;
200 
201 	setprogname(argv[0]);
202 	(void)setlocale(LC_ALL, "");
203 
204 	while ((ch = getopt(argc, argv, "a")) != -1) {
205 		switch (ch) {
206 		case 'a':
207 			a_flag = 1;
208 			break;
209 		case '?':
210 		default:
211 			usage();
212 		}
213 	}
214 	argc -= optind;
215 	argv += optind;
216 
217 	if (!a_flag) {
218 		if (argc == 0)
219 			usage();
220 		varname = argv[0];
221 		argc--;
222 		argv++;
223 	} else
224 		varname = NULL;
225 
226 	if (argc > 1)
227 		usage();
228 	pathname = argv[0];	/* may be NULL */
229 
230 	found = 0;
231 	vn = varname;
232 again:
233 	for (cp = conf_table; cp->name != NULL; cp++) {
234 		if (a_flag || strcmp(vn, cp->name) == 0) {
235 			if ((cp->type == PATHCONF) == (pathname != NULL)) {
236 				printvar(cp, pathname);
237 				found = 1;
238 			} else if (!a_flag)
239 				errx(EXIT_FAILURE,
240 				    "%s: invalid variable type", cp->name);
241 		}
242 	}
243 
244 	if (!a_flag && !found) {
245 		if (*vn++ == '_')
246 			goto again;
247 		errx(EXIT_FAILURE, "%s: unknown variable", varname);
248 	}
249 
250 	(void)fflush(stdout);
251 	return ferror(stdout) ? EXIT_FAILURE : EXIT_SUCCESS;
252 }
253 
254 static void
255 print_longvar(const char *name, long value)
256 {
257 	if (a_flag)
258 		(void)printf("%s = %ld\n", name, value);
259 	else
260 		(void)printf("%ld\n", value);
261 }
262 
263 static void
264 print_strvar(const char *name, const char *sval)
265 {
266 	if (a_flag)
267 		(void)printf("%s = %s\n", name, sval);
268 	else
269 		(void)printf("%s\n", sval);
270 }
271 
272 static void
273 printvar(const struct conf_variable *cp, const char *pathname)
274 {
275 	size_t slen;
276 	char *sval;
277 	long val;
278 
279 	switch (cp->type) {
280 	case CONSTANT:
281 		print_longvar(cp->name, cp->value);
282 		break;
283 
284 	case CONFSTR:
285 		errno = 0;
286 		slen = confstr((int)cp->value, NULL, 0);
287 		if (slen == 0) {
288 			if (errno != 0)
289 
290 out:			 	err(EXIT_FAILURE, "confstr(%ld)", cp->value);
291 			else
292 				print_strvar(cp->name, "undefined");
293 		}
294 
295 		if ((sval = malloc(slen)) == NULL)
296 			err(EXIT_FAILURE, "Can't allocate %zu bytes", slen);
297 
298 		errno = 0;
299 		if (confstr((int)cp->value, sval, slen) == 0) {
300 			if (errno != 0)
301 				goto out;
302 			else
303 				print_strvar(cp->name, "undefined");
304 		} else
305 			print_strvar(cp->name, sval);
306 
307 		free(sval);
308 		break;
309 
310 	case SYSCONF:
311 		errno = 0;
312 		if ((val = sysconf((int)cp->value)) == -1) {
313 			if (errno != 0)
314 				err(EXIT_FAILURE, "sysconf(%ld)", cp->value);
315 			print_strvar(cp->name, "undefined");
316 		} else
317 			print_longvar(cp->name, val);
318 		break;
319 
320 	case PATHCONF:
321 		errno = 0;
322 		if ((val = pathconf(pathname, (int)cp->value)) == -1) {
323 			if (errno != 0) {
324 				if (a_flag && errno == EINVAL) {
325 					/* Just skip invalid variables */
326 					return;
327 				}
328 				err(EXIT_FAILURE, "pathconf(%s, %ld)",
329 				    pathname, cp->value);
330 				/* NOTREACHED */
331 			}
332 
333 			print_strvar(cp->name, "undefined");
334 		} else
335 			print_longvar(cp->name, val);
336 		break;
337 	}
338 }
339 
340 
341 static void
342 usage(void)
343 {
344 	const char *p = getprogname();
345 	(void)fprintf(stderr, "Usage: %s system_var\n\t%s -a\n"
346 	    "\t%s path_var pathname\n\t%s -a pathname\n", p, p, p, p);
347 	exit(EXIT_FAILURE);
348 }
349