1/*	$NetBSD: getconf.c,v 1.37 2024/01/27 16:04:36 christos 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#ifndef lint
34__RCSID("$NetBSD: getconf.c,v 1.37 2024/01/27 16:04:36 christos Exp $");
35#endif /* not lint */
36
37#include <err.h>
38#include <errno.h>
39#include <limits.h>
40#include <locale.h>
41#include <stdio.h>
42#include <stdlib.h>
43#include <unistd.h>
44#include <string.h>
45
46struct conf_variable
47{
48  const char *name;
49  enum { SYSCONF, CONFSTR, PATHCONF, CONSTANT } type;
50  long value;
51};
52
53static void print_longvar(const char *, long);
54static void print_strvar(const char *, const char *);
55static void printvar(const struct conf_variable *, const char *);
56static void usage(void) __dead;
57
58static const struct conf_variable conf_table[] =
59{
60  { "PATH",			CONFSTR,	_CS_PATH		},
61
62  /* Utility Limit Minimum Values */
63  { "POSIX2_BC_BASE_MAX",	CONSTANT,	_POSIX2_BC_BASE_MAX	},
64  { "POSIX2_BC_DIM_MAX",	CONSTANT,	_POSIX2_BC_DIM_MAX	},
65  { "POSIX2_BC_SCALE_MAX",	CONSTANT,	_POSIX2_BC_SCALE_MAX	},
66  { "POSIX2_BC_STRING_MAX",	CONSTANT,	_POSIX2_BC_STRING_MAX	},
67  { "POSIX2_COLL_WEIGHTS_MAX",	CONSTANT,	_POSIX2_COLL_WEIGHTS_MAX },
68  { "POSIX2_EXPR_NEST_MAX",	CONSTANT,	_POSIX2_EXPR_NEST_MAX	},
69  { "POSIX2_LINE_MAX",		CONSTANT,	_POSIX2_LINE_MAX	},
70  { "POSIX2_RE_DUP_MAX",	CONSTANT,	_POSIX2_RE_DUP_MAX	},
71  { "POSIX2_VERSION",		CONSTANT,	_POSIX2_VERSION		},
72
73  /* POSIX.1 Minimum Values */
74  { "_POSIX_AIO_LISTIO_MAX",	CONSTANT,	_POSIX_AIO_LISTIO_MAX	},
75  { "_POSIX_AIO_MAX",		CONSTANT,       _POSIX_AIO_MAX		},
76  { "_POSIX_ARG_MAX",		CONSTANT,	_POSIX_ARG_MAX		},
77  { "_POSIX_CHILD_MAX",		CONSTANT,	_POSIX_CHILD_MAX	},
78  { "_POSIX_LINK_MAX",		CONSTANT,	_POSIX_LINK_MAX		},
79  { "_POSIX_MAX_CANON",		CONSTANT,	_POSIX_MAX_CANON	},
80  { "_POSIX_MAX_INPUT",		CONSTANT,	_POSIX_MAX_INPUT	},
81  { "_POSIX_MQ_OPEN_MAX",	CONSTANT,	_POSIX_MQ_OPEN_MAX	},
82  { "_POSIX_MQ_PRIO_MAX",	CONSTANT,	_POSIX_MQ_PRIO_MAX	},
83  { "_POSIX_NAME_MAX",		CONSTANT,	_POSIX_NAME_MAX		},
84  { "_POSIX_NGROUPS_MAX",	CONSTANT,	_POSIX_NGROUPS_MAX	},
85  { "_POSIX_OPEN_MAX",		CONSTANT,	_POSIX_OPEN_MAX		},
86  { "_POSIX_PATH_MAX",		CONSTANT,	_POSIX_PATH_MAX		},
87  { "_POSIX_PIPE_BUF",		CONSTANT,	_POSIX_PIPE_BUF		},
88  { "_POSIX_SSIZE_MAX",		CONSTANT,	_POSIX_SSIZE_MAX	},
89  { "_POSIX_STREAM_MAX",	CONSTANT,	_POSIX_STREAM_MAX	},
90  { "_POSIX_TZNAME_MAX",	CONSTANT,	_POSIX_TZNAME_MAX	},
91
92  /* Symbolic Utility Limits */
93  { "BC_BASE_MAX",		SYSCONF,	_SC_BC_BASE_MAX		},
94  { "BC_DIM_MAX",		SYSCONF,	_SC_BC_DIM_MAX		},
95  { "BC_SCALE_MAX",		SYSCONF,	_SC_BC_SCALE_MAX	},
96  { "BC_STRING_MAX",		SYSCONF,	_SC_BC_STRING_MAX	},
97  { "COLL_WEIGHTS_MAX",		SYSCONF,	_SC_COLL_WEIGHTS_MAX	},
98  { "EXPR_NEST_MAX",		SYSCONF,	_SC_EXPR_NEST_MAX	},
99  { "LINE_MAX",			SYSCONF,	_SC_LINE_MAX		},
100  { "RE_DUP_MAX",		SYSCONF,	_SC_RE_DUP_MAX		},
101
102  /* Optional Facility Configuration Values */
103  { "_POSIX2_C_BIND",		SYSCONF,	_SC_2_C_BIND		},
104  { "POSIX2_C_DEV",		SYSCONF,	_SC_2_C_DEV		},
105  { "POSIX2_CHAR_TERM",		SYSCONF,	_SC_2_CHAR_TERM		},
106  { "POSIX2_FORT_DEV",		SYSCONF,	_SC_2_FORT_DEV		},
107  { "POSIX2_FORT_RUN",		SYSCONF,	_SC_2_FORT_RUN		},
108  { "POSIX2_LOCALEDEF",		SYSCONF,	_SC_2_LOCALEDEF		},
109  { "POSIX2_SW_DEV",		SYSCONF,	_SC_2_SW_DEV		},
110  { "POSIX2_UPE",		SYSCONF,	_SC_2_UPE		},
111
112  /* POSIX.1 Configurable System Variables */
113  { "AIO_LISTIO_MAX",		SYSCONF,	_SC_AIO_LISTIO_MAX	},
114  { "AIO_MAX",			SYSCONF,	_SC_AIO_MAX		},
115  { "ARG_MAX",			SYSCONF,	_SC_ARG_MAX 		},
116  { "CHILD_MAX",		SYSCONF,	_SC_CHILD_MAX		},
117  { "CLK_TCK",			SYSCONF,	_SC_CLK_TCK		},
118  { "MQ_OPEN_MAX",		SYSCONF,	_SC_MQ_OPEN_MAX		},
119  { "MQ_PRIO_MAX",		SYSCONF,	_SC_MQ_PRIO_MAX		},
120  { "NGROUPS_MAX",		SYSCONF,	_SC_NGROUPS_MAX		},
121  { "OPEN_MAX",			SYSCONF,	_SC_OPEN_MAX		},
122  { "STREAM_MAX",		SYSCONF,	_SC_STREAM_MAX		},
123  { "TZNAME_MAX",		SYSCONF,	_SC_TZNAME_MAX		},
124  { "_POSIX_JOB_CONTROL",	SYSCONF,	_SC_JOB_CONTROL 	},
125  { "_POSIX_SAVED_IDS",		SYSCONF,	_SC_SAVED_IDS		},
126  { "_POSIX_VERSION",		SYSCONF,	_SC_VERSION		},
127
128  { "LINK_MAX",			PATHCONF,	_PC_LINK_MAX		},
129  { "MAX_CANON",		PATHCONF,	_PC_MAX_CANON		},
130  { "MAX_INPUT",		PATHCONF,	_PC_MAX_INPUT		},
131  { "NAME_MAX",			PATHCONF,	_PC_NAME_MAX		},
132  { "PATH_MAX",			PATHCONF,	_PC_PATH_MAX		},
133  { "PIPE_BUF",			PATHCONF,	_PC_PIPE_BUF		},
134  { "_POSIX_CHOWN_RESTRICTED",	PATHCONF,	_PC_CHOWN_RESTRICTED	},
135  { "_POSIX_NO_TRUNC",		PATHCONF,	_PC_NO_TRUNC		},
136  { "_POSIX_VDISABLE",		PATHCONF,	_PC_VDISABLE		},
137
138  /* POSIX.1b Configurable System Variables */
139  { "PAGESIZE",			SYSCONF,	_SC_PAGESIZE		},
140  { "_POSIX_ASYNCHRONOUS_IO",	SYSCONF,	_SC_ASYNCHRONOUS_IO	},
141  { "_POSIX_FSYNC",		SYSCONF,	_SC_FSYNC		},
142  { "_POSIX_MAPPED_FILES",	SYSCONF,	_SC_MAPPED_FILES	},
143  { "_POSIX_MEMLOCK",		SYSCONF,	_SC_MEMLOCK		},
144  { "_POSIX_MEMLOCK_RANGE",	SYSCONF,	_SC_MEMLOCK_RANGE	},
145  { "_POSIX_MEMORY_PROTECTION",	SYSCONF,	_SC_MEMORY_PROTECTION	},
146  { "_POSIX_MESSAGE_PASSING",	SYSCONF,	_SC_MESSAGE_PASSING	},
147  { "_POSIX_MONOTONIC_CLOCK",	SYSCONF,	_SC_MONOTONIC_CLOCK	},
148  { "_POSIX_PRIORITY_SCHEDULING", SYSCONF,	_SC_PRIORITY_SCHEDULING },
149  { "_POSIX_SEMAPHORES",	SYSCONF,	_SC_SEMAPHORES		},
150  { "_POSIX_SHARED_MEMORY_OBJECTS", SYSCONF,	_SC_SHARED_MEMORY_OBJECTS },
151  { "_POSIX_SYNCHRONIZED_IO",	SYSCONF,	_SC_SYNCHRONIZED_IO	},
152  { "_POSIX_TIMERS",		SYSCONF,	_SC_TIMERS		},
153
154  { "_POSIX_SYNC_IO",		PATHCONF,	_PC_SYNC_IO		},
155
156  /* POSIX.1c Configurable System Variables */
157  { "LOGIN_NAME_MAX",		SYSCONF,	_SC_LOGIN_NAME_MAX	},
158  { "_POSIX_THREADS",		SYSCONF,	_SC_THREADS		},
159
160  /* POSIX.1j Configurable System Variables */
161  { "_POSIX_BARRIERS",		SYSCONF,	_SC_BARRIERS		},
162  { "_POSIX_READER_WRITER_LOCKS", SYSCONF,	_SC_READER_WRITER_LOCKS	},
163  { "_POSIX_SPIN_LOCKS",	SYSCONF,	_SC_SPIN_LOCKS		},
164
165  /* XPG4.2 Configurable System Variables */
166  { "IOV_MAX",			SYSCONF,	_SC_IOV_MAX		},
167  { "PAGE_SIZE",		SYSCONF,	_SC_PAGE_SIZE		},
168  { "_XOPEN_SHM",		SYSCONF,	_SC_XOPEN_SHM		},
169
170  /* X/Open CAE Spec. Issue 5 Version 2 Configurable System Variables */
171  { "FILESIZEBITS",		PATHCONF,	_PC_FILESIZEBITS	},
172
173  /* POSIX.1-2001 XSI Option Group Configurable System Variables */
174  { "ATEXIT_MAX",		SYSCONF,	_SC_ATEXIT_MAX		},
175
176  /* POSIX.1-2001 TSF Configurable System Variables */
177  { "GETGR_R_SIZE_MAX",		SYSCONF,	_SC_GETGR_R_SIZE_MAX	},
178  { "GETPW_R_SIZE_MAX",		SYSCONF,	_SC_GETPW_R_SIZE_MAX	},
179
180  /* Extensions found in Solaris and Linux. */
181  { "SC_PHYS_PAGES",		SYSCONF,	_SC_PHYS_PAGES		},
182  { "SC_AVPHYS_PAGES",		SYSCONF,	_SC_AVPHYS_PAGES	},
183
184#ifdef _NETBSD_SOURCE
185  /* Commonly provided extensions */
186  { "NPROCESSORS_CONF",		SYSCONF,	_SC_NPROCESSORS_CONF	},
187  { "NPROCESSORS_ONLN",		SYSCONF,	_SC_NPROCESSORS_ONLN	},
188#endif	/* _NETBSD_SOURCE */
189
190  { NULL, CONSTANT, 0L }
191};
192
193static int a_flag = 0;		/* list all variables */
194
195int
196main(int argc, char **argv)
197{
198	int ch;
199	const struct conf_variable *cp;
200	const char *varname, *pathname, *vn;
201	int found;
202
203	setprogname(argv[0]);
204	(void)setlocale(LC_ALL, "");
205
206	while ((ch = getopt(argc, argv, "a")) != -1) {
207		switch (ch) {
208		case 'a':
209			a_flag = 1;
210			break;
211		case '?':
212		default:
213			usage();
214		}
215	}
216	argc -= optind;
217	argv += optind;
218
219	if (!a_flag) {
220		if (argc == 0)
221			usage();
222		varname = argv[0];
223		argc--;
224		argv++;
225	} else
226		varname = NULL;
227
228	if (argc > 1)
229		usage();
230	pathname = argv[0];	/* may be NULL */
231
232	found = 0;
233	vn = varname;
234again:
235	for (cp = conf_table; cp->name != NULL; cp++) {
236		if (a_flag || strcmp(vn, cp->name) == 0) {
237			/*LINTED weird expression*/
238			if ((cp->type == PATHCONF) == (pathname != NULL)) {
239				printvar(cp, pathname);
240				found = 1;
241			} else if (!a_flag)
242				errx(EXIT_FAILURE,
243				    "%s: invalid variable type", cp->name);
244		}
245	}
246
247	if (!a_flag && !found) {
248		if (*vn++ == '_')
249			goto again;
250		errx(EXIT_FAILURE, "%s: unknown variable", varname);
251	}
252
253	(void)fflush(stdout);
254	return ferror(stdout) ? EXIT_FAILURE : EXIT_SUCCESS;
255}
256
257static void
258print_longvar(const char *name, long value)
259{
260	if (a_flag)
261		(void)printf("%s = %ld\n", name, value);
262	else
263		(void)printf("%ld\n", value);
264}
265
266static void
267print_strvar(const char *name, const char *sval)
268{
269	if (a_flag)
270		(void)printf("%s = %s\n", name, sval);
271	else
272		(void)printf("%s\n", sval);
273}
274
275static void
276printvar(const struct conf_variable *cp, const char *pathname)
277{
278	size_t slen;
279	char *sval;
280	long val;
281
282	switch (cp->type) {
283	case CONSTANT:
284		print_longvar(cp->name, cp->value);
285		break;
286
287	case CONFSTR:
288		errno = 0;
289		slen = confstr((int)cp->value, NULL, 0);
290		if (slen == 0) {
291			if (errno != 0)
292
293out:			 	err(EXIT_FAILURE, "confstr(%ld)", cp->value);
294			else
295				print_strvar(cp->name, "undefined");
296		}
297
298		if ((sval = malloc(slen)) == NULL)
299			err(EXIT_FAILURE, "Can't allocate %zu bytes", slen);
300
301		errno = 0;
302		if (confstr((int)cp->value, sval, slen) == 0) {
303			if (errno != 0)
304				goto out;
305			else
306				print_strvar(cp->name, "undefined");
307		} else
308			print_strvar(cp->name, sval);
309
310		free(sval);
311		break;
312
313	case SYSCONF:
314		errno = 0;
315		if ((val = sysconf((int)cp->value)) == -1) {
316			if (errno != 0)
317				err(EXIT_FAILURE, "sysconf(%ld)", cp->value);
318			print_strvar(cp->name, "undefined");
319		} else
320			print_longvar(cp->name, val);
321		break;
322
323	case PATHCONF:
324		errno = 0;
325		if ((val = pathconf(pathname, (int)cp->value)) == -1) {
326			if (errno != 0) {
327				if (a_flag && errno == EINVAL) {
328					/* Just skip invalid variables */
329					return;
330				}
331				err(EXIT_FAILURE, "pathconf(%s, %ld)",
332				    pathname, cp->value);
333				/* NOTREACHED */
334			}
335
336			print_strvar(cp->name, "undefined");
337		} else
338			print_longvar(cp->name, val);
339		break;
340	}
341}
342
343
344static void
345usage(void)
346{
347	const char *p = getprogname();
348	(void)fprintf(stderr, "Usage: %s system_var\n\t%s -a\n"
349	    "\t%s path_var pathname\n\t%s -a pathname\n", p, p, p, p);
350	exit(EXIT_FAILURE);
351}
352