1 /*	$OpenBSD: id.c,v 1.17 2004/11/16 13:51:35 jmc Exp $	*/
2 
3 /*-
4  * Copyright (c) 1991, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #ifndef lint
33 static char copyright[] =
34 "@(#) Copyright (c) 1991, 1993\n\
35 	The Regents of the University of California.  All rights reserved.\n";
36 #endif /* not lint */
37 
38 #ifndef lint
39 /*static char sccsid[] = "@(#)id.c	8.3 (Berkeley) 4/28/95";*/
40 static char rcsid[] = "$OpenBSD: id.c,v 1.17 2004/11/16 13:51:35 jmc Exp $";
41 #endif /* not lint */
42 
43 #include <sys/param.h>
44 
45 #include <errno.h>
46 #include <grp.h>
47 #include <pwd.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <unistd.h>
52 #include <err.h>
53 
54 void	current(void);
55 void	pretty(struct passwd *);
56 void	group(struct passwd *, int);
57 void	usage(void);
58 void	user(struct passwd *);
59 struct passwd *
60 	who(char *);
61 
62 int
main(int argc,char * argv[])63 main(int argc, char *argv[])
64 {
65 	struct group *gr;
66 	struct passwd *pw;
67 	int Gflag, ch, gflag, nflag, pflag, rflag, uflag;
68 	uid_t uid;
69 	gid_t gid;
70 
71 	Gflag = gflag = nflag = pflag = rflag = uflag = 0;
72 	while ((ch = getopt(argc, argv, "Ggnpru")) != -1)
73 		switch(ch) {
74 		case 'G':
75 			Gflag = 1;
76 			break;
77 		case 'g':
78 			gflag = 1;
79 			break;
80 		case 'n':
81 			nflag = 1;
82 			break;
83 		case 'p':
84 			pflag = 1;
85 			break;
86 		case 'r':
87 			rflag = 1;
88 			break;
89 		case 'u':
90 			uflag = 1;
91 			break;
92 		case '?':
93 		default:
94 			usage();
95 		}
96 	argc -= optind;
97 	argv += optind;
98 
99 	switch(Gflag + gflag + pflag + uflag) {
100 	case 1:
101 		break;
102 	case 0:
103 		if (!nflag && !rflag)
104 			break;
105 		/* FALLTHROUGH */
106 	default:
107 		usage();
108 	}
109 
110 	pw = *argv ? who(*argv) : NULL;
111 
112 	if (gflag) {
113 		gid = pw ? pw->pw_gid : rflag ? getgid() : getegid();
114 		if (nflag && (gr = getgrgid(gid)))
115 			(void)printf("%s\n", gr->gr_name);
116 		else
117 			(void)printf("%u\n", gid);
118 		exit(0);
119 	}
120 
121 	if (uflag) {
122 		uid = pw ? pw->pw_uid : rflag ? getuid() : geteuid();
123 		if (nflag && (pw = getpwuid(uid)))
124 			(void)printf("%s\n", pw->pw_name);
125 		else
126 			(void)printf("%u\n", uid);
127 		exit(0);
128 	}
129 
130 	if (Gflag) {
131 		group(pw, nflag);
132 		exit(0);
133 	}
134 
135 	if (pflag) {
136 		pretty(pw);
137 		exit(0);
138 	}
139 
140 	if (pw)
141 		user(pw);
142 	else
143 		current();
144 	exit(0);
145 }
146 
147 void
pretty(struct passwd * pw)148 pretty(struct passwd *pw)
149 {
150 	struct group *gr;
151 	uid_t eid, rid;
152 	char *login;
153 
154 	if (pw) {
155 		(void)printf("uid\t%s\n", pw->pw_name);
156 		(void)printf("groups\t");
157 		group(pw, 1);
158 	} else {
159 		if ((login = getlogin()) == NULL)
160 			err(1, "getlogin");
161 
162 		pw = getpwuid(rid = getuid());
163 		if (pw == NULL || strcmp(login, pw->pw_name))
164 			(void)printf("login\t%s\n", login);
165 		if (pw)
166 			(void)printf("uid\t%s\n", pw->pw_name);
167 		else
168 			(void)printf("uid\t%u\n", rid);
169 
170 		if ((eid = geteuid()) != rid) {
171 			if ((pw = getpwuid(eid)))
172 				(void)printf("euid\t%s\n", pw->pw_name);
173 			else
174 				(void)printf("euid\t%u\n", eid);
175 		}
176 		if ((rid = getgid()) != (eid = getegid())) {
177 			if ((gr = getgrgid(rid)))
178 				(void)printf("rgid\t%s\n", gr->gr_name);
179 			else
180 				(void)printf("rgid\t%u\n", rid);
181 		}
182 		(void)printf("groups\t");
183 		group(NULL, 1);
184 	}
185 }
186 
187 void
current(void)188 current(void)
189 {
190 	struct group *gr;
191 	struct passwd *pw;
192 	int cnt, ngroups;
193 	uid_t uid, euid;
194 	gid_t groups[NGROUPS], gid, egid, lastgid;
195 	char *fmt;
196 
197 	uid = getuid();
198 	(void)printf("uid=%u", uid);
199 	if ((pw = getpwuid(uid)))
200 		(void)printf("(%s)", pw->pw_name);
201 	if ((euid = geteuid()) != uid) {
202 		(void)printf(" euid=%u", euid);
203 		if ((pw = getpwuid(euid)))
204 			(void)printf("(%s)", pw->pw_name);
205 	}
206 	gid = getgid();
207 	(void)printf(" gid=%u", gid);
208 	if ((gr = getgrgid(gid)))
209 		(void)printf("(%s)", gr->gr_name);
210 	if ((egid = getegid()) != gid) {
211 		(void)printf(" egid=%u", egid);
212 		if ((gr = getgrgid(egid)))
213 			(void)printf("(%s)", gr->gr_name);
214 	}
215 	if ((ngroups = getgroups(NGROUPS, groups))) {
216 		for (fmt = " groups=%u", lastgid = (gid_t)-1, cnt = 0; cnt < ngroups;
217 		    fmt = ", %u", lastgid = gid) {
218 			gid = groups[cnt++];
219 			if (lastgid == gid)
220 				continue;
221 			(void)printf(fmt, gid);
222 			if ((gr = getgrgid(gid)))
223 				(void)printf("(%s)", gr->gr_name);
224 		}
225 	}
226 	(void)printf("\n");
227 }
228 
229 void
user(struct passwd * pw)230 user(struct passwd *pw)
231 {
232 	gid_t gid, groups[NGROUPS + 1];
233 	int cnt, ngroups;
234 	uid_t uid;
235 	struct group *gr;
236 	char *fmt;
237 
238 	uid = pw->pw_uid;
239 	(void)printf("uid=%u(%s)", uid, pw->pw_name);
240 	(void)printf(" gid=%u", pw->pw_gid);
241 	if ((gr = getgrgid(pw->pw_gid)))
242 		(void)printf("(%s)", gr->gr_name);
243 	ngroups = NGROUPS + 1;
244 	(void) getgrouplist(pw->pw_name, pw->pw_gid, groups, &ngroups);
245 	fmt = " groups=%u";
246 	for (cnt = 0; cnt < ngroups;) {
247 		gid = groups[cnt];
248 		(void)printf(fmt, gid);
249 		fmt = ", %u";
250 		if ((gr = getgrgid(gid)))
251 			(void)printf("(%s)", gr->gr_name);
252 		/* Skip same gid entries. */
253 		while (++cnt < ngroups && gid == groups[cnt]);
254 	}
255 	(void)printf("\n");
256 }
257 
258 void
group(struct passwd * pw,int nflag)259 group(struct passwd *pw, int nflag)
260 {
261 	int cnt, ngroups;
262 	gid_t gid, groups[NGROUPS + 1];
263 	struct group *gr;
264 	char *fmt;
265 
266 	if (pw) {
267 		ngroups = NGROUPS + 1;
268 		(void) getgrouplist(pw->pw_name, pw->pw_gid, groups, &ngroups);
269 	} else {
270 		groups[0] = getgid();
271 		ngroups = getgroups(NGROUPS, groups + 1) + 1;
272 	}
273 	fmt = nflag ? "%s" : "%u";
274 	for (cnt = 0; cnt < ngroups;) {
275 		gid = groups[cnt];
276 		if (nflag) {
277 			if ((gr = getgrgid(gid)))
278 				(void)printf(fmt, gr->gr_name);
279 			else
280 				(void)printf(*fmt == ' ' ? " %u" : "%u",
281 				    gid);
282 			fmt = " %s";
283 		} else {
284 			(void)printf(fmt, gid);
285 			fmt = " %u";
286 		}
287 		/* Skip same gid entries. */
288 		while (++cnt < ngroups && gid == groups[cnt]);
289 	}
290 	(void)printf("\n");
291 }
292 
293 struct passwd *
who(char * u)294 who(char *u)
295 {
296 	struct passwd *pw;
297 	uid_t uid;
298 	const char *errstr;
299 
300 	/*
301 	 * Translate user argument into a pw pointer.  First, try to
302 	 * get it as specified.  If that fails, try it as a number.
303 	 */
304 	if ((pw = getpwnam(u)))
305 		return(pw);
306 	uid = strtonum(u, 0, UID_MAX, &errstr);
307 	if (!errstr && (pw = getpwuid(uid)))
308 		return(pw);
309 	errx(1, "%s: No such user", u);
310 	/* NOTREACHED */
311 }
312 
313 void
usage(void)314 usage(void)
315 {
316 	(void)fprintf(stderr, "usage: id [user]\n"
317 			      "       id -G [-n] [user]\n"
318 			      "       id -g [-nr] [user]\n"
319 			      "       id -p [user]\n"
320 			      "       id -u [-nr] [user]\n");
321 	exit(1);
322 }
323