xref: /netbsd-src/usr.bin/id/id.c (revision 23c8222edbfb0f0932d88a8351d3a0cf817dfb9e)
1 /*-
2  * Copyright (c) 1991, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 #ifndef lint
32 __COPYRIGHT("@(#) Copyright (c) 1991, 1993\n\
33 	The Regents of the University of California.  All rights reserved.\n");
34 #endif /* not lint */
35 
36 #ifndef lint
37 #if 0
38 static char sccsid[] = "@(#)id.c	8.3 (Berkeley) 4/28/95";
39 #else
40 __RCSID("$NetBSD: id.c,v 1.20 2003/10/21 02:17:45 fvdl Exp $");
41 #endif
42 #endif /* not lint */
43 
44 #include <sys/param.h>
45 
46 #include <err.h>
47 #include <errno.h>
48 #include <grp.h>
49 #include <pwd.h>
50 #include <stdio.h>
51 #include <stdlib.h>
52 #include <string.h>
53 #include <unistd.h>
54 
55 int	main __P((int, char **));
56 
57 static void	current __P((void));
58 static void	pretty __P((struct passwd *));
59 static void	group __P((struct passwd *, int));
60 static void	usage __P((void));
61 static void	user __P((struct passwd *));
62 static struct passwd *who __P((char *));
63 
64 static int maxgroups;
65 static gid_t *groups;
66 
67 int
68 main(argc, argv)
69 	int argc;
70 	char *argv[];
71 {
72 	struct group *gr;
73 	struct passwd *pw;
74 	int ch, id;
75 	int Gflag, gflag, nflag, pflag, rflag, uflag;
76 
77 	Gflag = gflag = nflag = pflag = rflag = uflag = 0;
78 
79 	if (!strcmp(getprogname(), "groups")) {
80 		Gflag = 1;
81 		nflag = 1;
82 	} else if (!strcmp(getprogname(), "whoami")) {
83 		uflag = 1;
84 		nflag = 1;
85 	}
86 
87 	while ((ch = getopt(argc, argv, "Ggnpru")) != -1)
88 		switch(ch) {
89 		case 'G':
90 			Gflag = 1;
91 			break;
92 		case 'g':
93 			gflag = 1;
94 			break;
95 		case 'n':
96 			nflag = 1;
97 			break;
98 		case 'p':
99 			pflag = 1;
100 			break;
101 		case 'r':
102 			rflag = 1;
103 			break;
104 		case 'u':
105 			uflag = 1;
106 			break;
107 		case '?':
108 		default:
109 			usage();
110 		}
111 	argc -= optind;
112 	argv += optind;
113 
114 	switch(Gflag + gflag + pflag + uflag) {
115 	case 1:
116 		break;
117 	case 0:
118 		if (!nflag && !rflag)
119 			break;
120 		/* FALLTHROUGH */
121 	default:
122 		usage();
123 	}
124 
125 	pw = *argv ? who(*argv) : NULL;
126 
127 	maxgroups = sysconf(_SC_NGROUPS_MAX);
128 	if ((groups = malloc((maxgroups + 1) * sizeof(gid_t))) == NULL)
129 		err(1, NULL);
130 
131 	if (gflag) {
132 		id = pw ? pw->pw_gid : rflag ? getgid() : getegid();
133 		if (nflag && (gr = getgrgid(id)))
134 			(void)printf("%s\n", gr->gr_name);
135 		else
136 			(void)printf("%u\n", id);
137 		goto done;
138 	}
139 
140 	if (uflag) {
141 		id = pw ? pw->pw_uid : rflag ? getuid() : geteuid();
142 		if (nflag && (pw = getpwuid(id)))
143 			(void)printf("%s\n", pw->pw_name);
144 		else
145 			(void)printf("%u\n", id);
146 		goto done;
147 	}
148 
149 	if (Gflag) {
150 		group(pw, nflag);
151 		goto done;
152 	}
153 
154 	if (pflag) {
155 		pretty(pw);
156 		goto done;
157 	}
158 
159 	if (pw)
160 		user(pw);
161 	else
162 		current();
163 done:
164 	free(groups);
165 	return(0);
166 }
167 
168 static void
169 pretty(pw)
170 	struct passwd *pw;
171 {
172 	struct group *gr;
173 	u_int eid, rid;
174 	char *login;
175 
176 	if (pw) {
177 		(void)printf("uid\t%s\n", pw->pw_name);
178 		(void)printf("groups\t");
179 		group(pw, 1);
180 	} else {
181 		if ((login = getlogin()) == NULL)
182 			err(1, "getlogin");
183 
184 		pw = getpwuid(rid = getuid());
185 		if (pw == NULL || strcmp(login, pw->pw_name))
186 			(void)printf("login\t%s\n", login);
187 		if (pw)
188 			(void)printf("uid\t%s\n", pw->pw_name);
189 		else
190 			(void)printf("uid\t%u\n", rid);
191 
192 		if ((eid = geteuid()) != rid) {
193 			if ((pw = getpwuid(eid)) != NULL)
194 				(void)printf("euid\t%s\n", pw->pw_name);
195 			else
196 				(void)printf("euid\t%u\n", eid);
197 		}
198 		if ((rid = getgid()) != (eid = getegid())) {
199 			if ((gr = getgrgid(rid)) != NULL)
200 				(void)printf("rgid\t%s\n", gr->gr_name);
201 			else
202 				(void)printf("rgid\t%u\n", rid);
203 		}
204 		(void)printf("groups\t");
205 		group(NULL, 1);
206 	}
207 }
208 
209 static void
210 current()
211 {
212 	struct group *gr;
213 	struct passwd *pw;
214 	int cnt, id, eid, lastid, ngroups;
215 	char *fmt;
216 
217 	id = getuid();
218 	(void)printf("uid=%u", id);
219 	if ((pw = getpwuid(id)) != NULL)
220 		(void)printf("(%s)", pw->pw_name);
221 	if ((eid = geteuid()) != id) {
222 		(void)printf(" euid=%u", eid);
223 		if ((pw = getpwuid(eid)) != NULL)
224 			(void)printf("(%s)", pw->pw_name);
225 	}
226 	id = getgid();
227 	(void)printf(" gid=%u", id);
228 	if ((gr = getgrgid(id)) != NULL)
229 		(void)printf("(%s)", gr->gr_name);
230 	if ((eid = getegid()) != id) {
231 		(void)printf(" egid=%u", eid);
232 		if ((gr = getgrgid(eid)) != NULL)
233 			(void)printf("(%s)", gr->gr_name);
234 	}
235 	if ((ngroups = getgroups(maxgroups, groups)) != 0) {
236 		for (fmt = " groups=%u", lastid = -1, cnt = 0; cnt < ngroups;
237 		    fmt = ",%u", lastid = id, cnt++) {
238 			id = groups[cnt];
239 			if (lastid == id)
240 				continue;
241 			(void)printf(fmt, id);
242 			if ((gr = getgrgid(id)) != NULL)
243 				(void)printf("(%s)", gr->gr_name);
244 		}
245 	}
246 	(void)printf("\n");
247 }
248 
249 static void
250 user(pw)
251 	struct passwd *pw;
252 {
253 	struct group *gr;
254 	char *fmt;
255 	int cnt, id, lastid, ngroups;
256 
257 	id = pw->pw_uid;
258 	(void)printf("uid=%u(%s)", id, pw->pw_name);
259 	(void)printf(" gid=%lu", (u_long)pw->pw_gid);
260 	if ((gr = getgrgid(pw->pw_gid)) != NULL)
261 		(void)printf("(%s)", gr->gr_name);
262 	ngroups = maxgroups + 1;
263 	(void) getgrouplist(pw->pw_name, pw->pw_gid, groups, &ngroups);
264 	for (fmt = " groups=%u", lastid = -1, cnt = 0; cnt < ngroups;
265 	    fmt=",%u", lastid = id, cnt++) {
266 		id = groups[cnt];
267 		if (lastid == id)
268 			continue;
269 		(void)printf(fmt, id);
270 		if ((gr = getgrgid(id)) != NULL)
271 			(void)printf("(%s)", gr->gr_name);
272 	}
273 	(void)printf("\n");
274 }
275 
276 static void
277 group(pw, nflag)
278 	struct passwd *pw;
279 	int nflag;
280 {
281 	struct group *gr;
282 	int cnt, id, lastid, ngroups;
283 	char *fmt;
284 
285 	if (pw) {
286 		ngroups = maxgroups;
287 		(void) getgrouplist(pw->pw_name, pw->pw_gid, groups, &ngroups);
288 	} else {
289 		groups[0] = getgid();
290 		ngroups = getgroups(maxgroups, groups + 1) + 1;
291 	}
292 	fmt = nflag ? "%s" : "%u";
293 	for (lastid = -1, cnt = 0; cnt < ngroups; ++cnt) {
294 		if (lastid == (id = groups[cnt]))
295 			continue;
296 		if (nflag) {
297 			if ((gr = getgrgid(id)) != NULL)
298 				(void)printf(fmt, gr->gr_name);
299 			else
300 				(void)printf(*fmt == ' ' ? " %u" : "%u",
301 				    id);
302 			fmt = " %s";
303 		} else {
304 			(void)printf(fmt, id);
305 			fmt = " %u";
306 		}
307 		lastid = id;
308 	}
309 	(void)printf("\n");
310 }
311 
312 struct passwd *
313 who(u)
314 	char *u;
315 {
316 	struct passwd *pw;
317 	long id;
318 	char *ep;
319 
320 	/*
321 	 * Translate user argument into a pw pointer.  First, try to
322 	 * get it as specified.  If that fails, try it as a number.
323 	 */
324 	if ((pw = getpwnam(u)) != NULL)
325 		return(pw);
326 	id = strtol(u, &ep, 10);
327 	if (*u && !*ep && (pw = getpwuid(id)))
328 		return(pw);
329 	errx(1, "%s: No such user", u);
330 	/* NOTREACHED */
331 	return (NULL);
332 }
333 
334 void
335 usage()
336 {
337 	(void)fprintf(stderr, "usage: id [user]\n");
338 	(void)fprintf(stderr, "       id -G [-n] [user]\n");
339 	(void)fprintf(stderr, "       id -g [-nr] [user]\n");
340 	(void)fprintf(stderr, "       id -p\n");
341 	(void)fprintf(stderr, "       id -u [-nr] [user]\n");
342 	exit(1);
343 }
344