xref: /titanic_44/usr/src/lib/libcmd/common/getconf.c (revision 24fe0b3bf671e123467ce1df0b67cadd3614c8e4)
1 /***********************************************************************
2 *                                                                      *
3 *               This software is part of the ast package               *
4 *          Copyright (c) 1992-2008 AT&T Intellectual Property          *
5 *                      and is licensed under the                       *
6 *                  Common Public License, Version 1.0                  *
7 *                    by AT&T Intellectual Property                     *
8 *                                                                      *
9 *                A copy of the License is available at                 *
10 *            http://www.opensource.org/licenses/cpl1.0.txt             *
11 *         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
12 *                                                                      *
13 *              Information and Software Systems Research               *
14 *                            AT&T Research                             *
15 *                           Florham Park NJ                            *
16 *                                                                      *
17 *                 Glenn Fowler <gsf@research.att.com>                  *
18 *                  David Korn <dgk@research.att.com>                   *
19 *                                                                      *
20 ***********************************************************************/
21 #pragma prototyped
22 /*
23  * Glenn Fowler
24  * AT&T Research
25  *
26  * getconf - get configuration values
27  */
28 
29 static const char usage[] =
30 "[-?\n@(#)$Id: getconf (AT&T Research) 2008-04-24 $\n]"
31 USAGE_LICENSE
32 "[+NAME?getconf - get configuration values]"
33 "[+DESCRIPTION?\bgetconf\b displays the system configuration value for"
34 "	\aname\a. If \aname\a is a filesystem specific variable then"
35 "	the value is determined relative to \apath\a or the current"
36 "	directory if \apath\a is omitted. If \avalue\a is specified then"
37 "	\bgetconf\b attempts to change the process local value to \avalue\a."
38 "	\b-\b may be used in place of \apath\a when it is not relevant."
39 "	If \apath\a is \b=\b then the the \avalue\a is cached and used"
40 "	for subsequent tests in the calling and all child processes."
41 "	Only \bwritable\b variables may be set; \breadonly\b variables"
42 "	cannot be changed.]"
43 "[+?The current value for \aname\a is written to the standard output. If"
44 "	\aname\a is valid but undefined then \bundefined\b is written to"
45 "	the standard output. If \aname\a is invalid or an error occurs in"
46 "	determining its value, then a diagnostic written to the standard error"
47 "	and \bgetconf\b exits with a non-zero exit status.]"
48 "[+?More than one variable may be set or queried by providing the \aname\a"
49 "	\apath\a \avalue\a 3-tuple for each variable, specifying \b-\b for"
50 "	\avalue\a when querying.]"
51 "[+?If no operands are specified then all known variables are written in"
52 "	\aname\a=\avalue\a form to the standard output, one per line."
53 "	Only one of \b--call\b, \b--name\b or \b--standard\b may be specified.]"
54 "[+?This implementation uses the \bastgetconf\b(3) string interface to the native"
55 "	\bsysconf\b(2), \bconfstr\b(2), \bpathconf\b(2), and \bsysinfo\b(2)"
56 "	system calls. If \bgetconf\b on \b$PATH\b is not the default native"
57 "	\bgetconf\b, named by \b$(getconf GETCONF)\b, then \bastgetconf\b(3)"
58 "	checks only \bast\b specific extensions and the native system calls;"
59 "	invalid options and/or names not supported by \bastgetconf\b(3) cause"
60 "	the \bgetconf\b on \b$PATH\b to be executed.]"
61 
62 "[a:all?Call the native \bgetconf\b(1) with option \b-a\b.]"
63 "[b:base?List base variable name sans call and standard prefixes.]"
64 "[c:call?Display variables with call prefix that matches \aRE\a. The call"
65 "	prefixes are:]:[RE]{"
66 "		[+CS?\bconfstr\b(2)]"
67 "		[+PC?\bpathconf\b(2)]"
68 "		[+SC?\bsysconf\b(2)]"
69 "		[+SI?\bsysinfo\b(2)]"
70 "		[+XX?Constant value.]"
71 "}"
72 "[d:defined?Only display defined values when no operands are specified.]"
73 "[l:lowercase?List variable names in lower case.]"
74 "[n:name?Display variables with name that match \aRE\a.]:[RE]"
75 "[p:portable?Display the named \bwritable\b variables and values in a form that"
76 "	can be directly executed by \bsh\b(1) to set the values. If \aname\a"
77 "	is omitted then all \bwritable\b variables are listed.]"
78 "[q:quote?\"...\" quote values.]"
79 "[r:readonly?Display the named \breadonly\b variables in \aname\a=\avalue\a form."
80 "	If \aname\a is omitted then all \breadonly\b variables are listed.]"
81 "[s:standard?Display variables with standard prefix that matches \aRE\a."
82 "	Use the \b--table\b option to view all standard prefixes, including"
83 "	local additions. The standard prefixes available on all systems"
84 "	are:]:[RE]{"
85 "		[+AES]"
86 "		[+AST]"
87 "		[+C]"
88 "		[+GNU]"
89 "		[+POSIX]"
90 "		[+SVID]"
91 "		[+XBS5]"
92 "		[+XOPEN]"
93 "		[+XPG]"
94 "}"
95 "[t:table?Display the internal table that contains the name, standard,"
96 "	standard section, and system call symbol prefix for each variable.]"
97 "[w:writable?Display the named \bwritable\b variables in \aname\a=\avalue\a"
98 "	form. If \aname\a is omitted then all \bwritable\b variables are"
99 "	listed.]"
100 "[v:specification?Call the native \bgetconf\b(1) with option"
101 "	\b-v\b \aname\a.]:[name]"
102 
103 "\n"
104 "\n[ name [ path [ value ] ] ... ]\n"
105 "\n"
106 
107 "[+ENVIRONMENT]{"
108 "	[+_AST_FEATURES?Process local writable values that are different from"
109 "		the default are stored in the \b_AST_FEATURES\b environment"
110 "		variable. The \b_AST_FEATURES\b value is a space-separated"
111 "		list of \aname\a \apath\a \avalue\a 3-tuples, where"
112 "		\aname\a is the system configuration name, \apath\a is the"
113 "		corresponding path, \b-\b if no path is applicable, and"
114 "		\avalue\a is the system configuration value.]"
115 "}"
116 "[+SEE ALSO?\bpathchk\b(1), \bconfstr\b(2), \bpathconf\b(2),"
117 "	\bsysconf\b(2), \bastgetconf\b(3)]"
118 ;
119 
120 #include <cmd.h>
121 #include <proc.h>
122 #include <ls.h>
123 
124 typedef struct Path_s
125 {
126 	const char*	path;
127 	int		len;
128 } Path_t;
129 
130 int
131 b_getconf(int argc, char** argv, void* context)
132 {
133 	register char*		name;
134 	register char*		path;
135 	register char*		value;
136 	register const char*	s;
137 	register const char*	t;
138 	char*			pattern;
139 	char*			native;
140 	char*			cmd;
141 	Path_t*			e;
142 	Path_t*			p;
143 	int			flags;
144 	int			n;
145 	int			i;
146 	int			m;
147 	int			q;
148 	char**			oargv;
149 	char			buf[PATH_MAX];
150 	Path_t			std[64];
151 	struct stat		st0;
152 	struct stat		st1;
153 
154 	static const char	empty[] = "-";
155 	static const Path_t	equiv[] = { { "/bin", 4 }, { "/usr/bin", 8 } };
156 
157 	cmdinit(argc, argv, context, ERROR_CATALOG, 0);
158 	oargv = argv;
159 	if (*(native = astconf("GETCONF", NiL, NiL)) != '/')
160 		native = 0;
161 	flags = 0;
162 	name = 0;
163 	pattern = 0;
164 	for (;;)
165 	{
166 		switch (optget(argv, usage))
167 		{
168 		case 'a':
169 			if (native)
170 				goto defer;
171 			continue;
172 		case 'b':
173 			flags |= ASTCONF_base;
174 			continue;
175 		case 'c':
176 			flags |= ASTCONF_matchcall;
177 			pattern = opt_info.arg;
178 			continue;
179 		case 'd':
180 			flags |= ASTCONF_defined;
181 			continue;
182 		case 'l':
183 			flags |= ASTCONF_lower;
184 			continue;
185 		case 'n':
186 			flags |= ASTCONF_matchname;
187 			pattern = opt_info.arg;
188 			continue;
189 		case 'p':
190 			flags |= ASTCONF_parse;
191 			continue;
192 		case 'q':
193 			flags |= ASTCONF_quote;
194 			continue;
195 		case 'r':
196 			flags |= ASTCONF_read;
197 			continue;
198 		case 's':
199 			flags |= ASTCONF_matchstandard;
200 			pattern = opt_info.arg;
201 			continue;
202 		case 't':
203 			flags |= ASTCONF_table;
204 			continue;
205 		case 'v':
206 			if (native)
207 				goto defer;
208 			continue;
209 		case 'w':
210 			flags |= ASTCONF_write;
211 			continue;
212 		case ':':
213 			if (native)
214 				goto defer;
215 			error(2, "%s", opt_info.arg);
216 			break;
217 		case '?':
218 			error(ERROR_usage(2), "%s", opt_info.arg);
219 			break;
220 		}
221 		break;
222 	}
223 	argv += opt_info.index;
224 	if (!(name = *argv))
225 		path = 0;
226 	else if (streq(name, empty))
227 	{
228 		name = 0;
229 		if (path = *++argv)
230 		{
231 			argv++;
232 			if (streq(path, empty))
233 				path = 0;
234 		}
235 	}
236 	if (error_info.errors || !name && *argv)
237 		error(ERROR_usage(2), "%s", optusage(NiL));
238 	if (!name)
239 		astconflist(sfstdout, path, flags, pattern);
240 	else
241 	{
242 		flags = native ? (ASTCONF_system|ASTCONF_error) : 0;
243 		do
244 		{
245 			if (!(path = *++argv))
246 				value = 0;
247 			else
248 			{
249 				if (streq(path, empty))
250 				{
251 					path = 0;
252 					flags = 0;
253 				}
254 				if ((value = *++argv) && (streq(value, empty)))
255 				{
256 					value = 0;
257 					flags = 0;
258 				}
259 			}
260 			s = astgetconf(name, path, value, flags, errorf);
261 			if (error_info.errors)
262 				break;
263 			if (!s)
264 				goto defer;
265 			if (!value)
266 			{
267 				if (flags & ASTCONF_write)
268 				{
269 					sfputr(sfstdout, name, ' ');
270 					sfputr(sfstdout, path ? path : empty, ' ');
271 				}
272 				sfputr(sfstdout, s, '\n');
273 			}
274 		} while (*argv && (name = *++argv));
275 	}
276 	return error_info.errors != 0;
277 
278  defer:
279 
280 	/*
281 	 * defer to argv[0] if absolute and it exists
282 	 */
283 
284 	if ((cmd = oargv[0]) && *cmd == '/' && !access(cmd, X_OK))
285 		goto found;
286 
287 	/*
288 	 * defer to the first getconf on $PATH that is also on the standard PATH
289 	 */
290 
291 	e = std;
292 	s = astconf("PATH", NiL, NiL);
293 	q = !stat(equiv[0].path, &st0) && !stat(equiv[1].path, &st1) && st0.st_ino == st1.st_ino && st0.st_dev == st1.st_dev;
294 	m = 0;
295 	do
296 	{
297 		for (t = s; *s && *s != ':'; s++);
298 		if ((n = s - t) && *t == '/')
299 		{
300 			if (q)
301 				for (i = 0; i < 2; i++)
302 					if (n == equiv[i].len && !strncmp(t, equiv[i].path, n))
303 					{
304 						if (m & (i+1))
305 							t = 0;
306 						else
307 						{
308 							m |= (i+1);
309 							if (!(m & (!i+1)))
310 							{
311 								m |= (!i+1);
312 								e->path = t;
313 								e->len = n;
314 								e++;
315 								if (e >= &std[elementsof(std)])
316 									break;
317 								t = equiv[!i].path;
318 								n = equiv[!i].len;
319 							}
320 						}
321 					}
322 			if (t)
323 			{
324 				e->path = t;
325 				e->len = n;
326 				e++;
327 			}
328 		}
329 		while (*s == ':')
330 			s++;
331 	} while (*s && e < &std[elementsof(std)]);
332 	if (e < &std[elementsof(std)])
333 	{
334 		e->len = strlen(e->path = "/usr/sbin");
335 		if (++e < &std[elementsof(std)])
336 		{
337 			e->len = strlen(e->path = "/sbin");
338 			e++;
339 		}
340 	}
341 	if (s = getenv("PATH"))
342 		do
343 		{
344 			for (t = s; *s && *s != ':'; s++);
345 			if ((n = s - t) && *t == '/')
346 			{
347 				for (p = std; p < e; p++)
348 					if (p->len == n && !strncmp(t, p->path, n))
349 					{
350 						sfsprintf(buf, sizeof(buf), "%-*.*s/%s", n, n, t, error_info.id);
351 						if (!access(buf, X_OK))
352 						{
353 							cmd = buf;
354 							goto found;
355 						}
356 					}
357 			}
358 			while (*s == ':')
359 				s++;
360 		} while (*s);
361 
362 	/*
363 	 * defer to the first getconf on the standard PATH
364 	 */
365 
366 	for (p = std; p < e; p++)
367 	{
368 		sfsprintf(buf, sizeof(buf), "%-*.*s/%s", p->len, p->len, p->path, error_info.id);
369 		if (!access(buf, X_OK))
370 		{
371 			cmd = buf;
372 			goto found;
373 		}
374 	}
375 
376 	/*
377 	 * out of deferrals
378 	 */
379 
380 	if (name)
381 		error(4, "%s: unknown name -- no native getconf(1) to defer to", name);
382 	else
383 		error(4, "no native getconf(1) to defer to");
384 	return 2;
385 
386  found:
387 
388 	/*
389 	 * don't blame us for crappy diagnostics
390 	 */
391 
392 	oargv[0] = cmd;
393 	if ((n = sh_run(context, argc, oargv)) >= EXIT_NOEXEC)
394 		error(ERROR_SYSTEM|2, "%s: exec error [%d]", cmd, n);
395 	return n;
396 }
397