xref: /freebsd/usr.bin/id/id.c (revision 5773cccf19ef7b97e56c1101aa481c43149224da)
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. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #ifndef lint
35 static const char copyright[] =
36 "@(#) Copyright (c) 1991, 1993\n\
37 	The Regents of the University of California.  All rights reserved.\n";
38 #endif /* not lint */
39 
40 #ifndef lint
41 #if 0
42 static char sccsid[] = "@(#)id.c	8.2 (Berkeley) 2/16/94";
43 #endif
44 #endif /* not lint */
45 #include <sys/cdefs.h>
46 __FBSDID("$FreeBSD$");
47 
48 #include <sys/param.h>
49 
50 #include <err.h>
51 #include <grp.h>
52 #include <pwd.h>
53 #include <stdio.h>
54 #include <stdlib.h>
55 #include <string.h>
56 #include <unistd.h>
57 
58 void	current(void);
59 void	pline(struct passwd *);
60 void	pretty(struct passwd *);
61 void	group(struct passwd *, int);
62 void	usage(void);
63 void	user(struct passwd *);
64 struct passwd *
65 	who(char *);
66 
67 int isgroups, iswhoami;
68 
69 int
70 main(int argc, char *argv[])
71 {
72 	struct group *gr;
73 	struct passwd *pw;
74 	int Gflag, Pflag, ch, gflag, id, nflag, pflag, rflag, uflag;
75 	const char *myname;
76 
77 	Gflag = Pflag = gflag = nflag = pflag = rflag = uflag = 0;
78 
79 	myname = strrchr(argv[0], '/');
80 	myname = (myname != NULL) ? myname + 1 : argv[0];
81 	if (strcmp(myname, "groups") == 0) {
82 		isgroups = 1;
83 		Gflag = nflag = 1;
84 	}
85 	else if (strcmp(myname, "whoami") == 0) {
86 		iswhoami = 1;
87 		uflag = nflag = 1;
88 	}
89 
90 	while ((ch = getopt(argc, argv,
91 	    (isgroups || iswhoami) ? "" : "PGgnpru")) != -1)
92 		switch(ch) {
93 		case 'G':
94 			Gflag = 1;
95 			break;
96 		case 'P':
97 			Pflag = 1;
98 			break;
99 		case 'g':
100 			gflag = 1;
101 			break;
102 		case 'n':
103 			nflag = 1;
104 			break;
105 		case 'p':
106 			pflag = 1;
107 			break;
108 		case 'r':
109 			rflag = 1;
110 			break;
111 		case 'u':
112 			uflag = 1;
113 			break;
114 		case '?':
115 		default:
116 			usage();
117 		}
118 	argc -= optind;
119 	argv += optind;
120 
121 	if (iswhoami && argc > 0)
122 		usage();
123 
124 	switch(Gflag + Pflag + gflag + pflag + uflag) {
125 	case 1:
126 		break;
127 	case 0:
128 		if (!nflag && !rflag)
129 			break;
130 		/* FALLTHROUGH */
131 	default:
132 		usage();
133 	}
134 
135 	pw = *argv ? who(*argv) : NULL;
136 
137 	if (gflag) {
138 		id = pw ? pw->pw_gid : rflag ? getgid() : getegid();
139 		if (nflag && (gr = getgrgid(id)))
140 			(void)printf("%s\n", gr->gr_name);
141 		else
142 			(void)printf("%u\n", id);
143 		exit(0);
144 	}
145 
146 	if (uflag) {
147 		id = pw ? pw->pw_uid : rflag ? getuid() : geteuid();
148 		if (nflag && (pw = getpwuid(id)))
149 			(void)printf("%s\n", pw->pw_name);
150 		else
151 			(void)printf("%u\n", id);
152 		exit(0);
153 	}
154 
155 	if (Gflag) {
156 		group(pw, nflag);
157 		exit(0);
158 	}
159 
160 	if (Pflag) {
161 		pline(pw);
162 		exit(0);
163 	}
164 
165 	if (pflag) {
166 		pretty(pw);
167 		exit(0);
168 	}
169 
170 	if (pw)
171 		user(pw);
172 	else
173 		current();
174 	exit(0);
175 }
176 
177 void
178 pretty(struct passwd *pw)
179 {
180 	struct group *gr;
181 	u_int eid, rid;
182 	char *login;
183 
184 	if (pw) {
185 		(void)printf("uid\t%s\n", pw->pw_name);
186 		(void)printf("groups\t");
187 		group(pw, 1);
188 	} else {
189 		if ((login = getlogin()) == NULL)
190 			err(1, "getlogin");
191 
192 		pw = getpwuid(rid = getuid());
193 		if (pw == NULL || strcmp(login, pw->pw_name))
194 			(void)printf("login\t%s\n", login);
195 		if (pw)
196 			(void)printf("uid\t%s\n", pw->pw_name);
197 		else
198 			(void)printf("uid\t%u\n", rid);
199 
200 		if ((eid = geteuid()) != rid) {
201 			if ((pw = getpwuid(eid)))
202 				(void)printf("euid\t%s\n", pw->pw_name);
203 			else
204 				(void)printf("euid\t%u\n", eid);
205 		}
206 		if ((rid = getgid()) != (eid = getegid())) {
207 			if ((gr = getgrgid(rid)))
208 				(void)printf("rgid\t%s\n", gr->gr_name);
209 			else
210 				(void)printf("rgid\t%u\n", rid);
211 		}
212 		(void)printf("groups\t");
213 		group(NULL, 1);
214 	}
215 }
216 
217 void
218 current(void)
219 {
220 	struct group *gr;
221 	struct passwd *pw;
222 	int cnt, id, eid, lastid, ngroups;
223 	gid_t groups[NGROUPS];
224 	const char *fmt;
225 
226 	id = getuid();
227 	(void)printf("uid=%u", id);
228 	if ((pw = getpwuid(id)))
229 		(void)printf("(%s)", pw->pw_name);
230 	if ((eid = geteuid()) != id) {
231 		(void)printf(" euid=%u", eid);
232 		if ((pw = getpwuid(eid)))
233 			(void)printf("(%s)", pw->pw_name);
234 	}
235 	id = getgid();
236 	(void)printf(" gid=%u", id);
237 	if ((gr = getgrgid(id)))
238 		(void)printf("(%s)", gr->gr_name);
239 	if ((eid = getegid()) != id) {
240 		(void)printf(" egid=%u", eid);
241 		if ((gr = getgrgid(eid)))
242 			(void)printf("(%s)", gr->gr_name);
243 	}
244 	if ((ngroups = getgroups(NGROUPS, groups))) {
245 		for (fmt = " groups=%u", lastid = -1, cnt = 0; cnt < ngroups;
246 		    fmt = ", %u", lastid = id) {
247 			id = groups[cnt++];
248 			if (lastid == id)
249 				continue;
250 			(void)printf(fmt, id);
251 			if ((gr = getgrgid(id)))
252 				(void)printf("(%s)", gr->gr_name);
253 		}
254 	}
255 	(void)printf("\n");
256 }
257 
258 void
259 user(struct passwd *pw)
260 {
261 	struct group *gr;
262 	const char *fmt;
263 	int cnt, gid, lastgid, ngroups, groups[NGROUPS + 1];
264 
265 	(void)printf("uid=%u(%s)", pw->pw_uid, pw->pw_name);
266 	gid = pw->pw_gid;
267 	(void)printf(" gid=%u", gid);
268 	if ((gr = getgrgid(gid)))
269 		(void)printf("(%s)", gr->gr_name);
270 	ngroups = NGROUPS + 1;
271 	(void) getgrouplist(pw->pw_name, gid, groups, &ngroups);
272 	fmt = " groups=%u";
273 	for (lastgid = -1, cnt = 0; cnt < ngroups; ++cnt) {
274 		if (lastgid == (gid = groups[cnt]))
275 			continue;
276 		(void)printf(fmt, gid);
277 		fmt = ", %u";
278 		if ((gr = getgrgid(gid)))
279 			(void)printf("(%s)", gr->gr_name);
280 		lastgid = gid;
281 	}
282 	(void)printf("\n");
283 }
284 
285 void
286 group(struct passwd *pw, int nflag)
287 {
288 	struct group *gr;
289 	int cnt, id, lastid, ngroups;
290 	gid_t groups[NGROUPS + 1];
291 	const char *fmt;
292 
293 	if (pw) {
294 		ngroups = NGROUPS + 1;
295 		(void) getgrouplist(pw->pw_name, pw->pw_gid, groups, &ngroups);
296 	} else {
297 		groups[0] = getgid();
298 		ngroups = getgroups(NGROUPS, groups + 1) + 1;
299 	}
300 	fmt = nflag ? "%s" : "%u";
301 	for (lastid = -1, cnt = 0; cnt < ngroups; ++cnt) {
302 		if (lastid == (id = groups[cnt]))
303 			continue;
304 		if (nflag) {
305 			if ((gr = getgrgid(id)))
306 				(void)printf(fmt, gr->gr_name);
307 			else
308 				(void)printf(*fmt == ' ' ? " %u" : "%u",
309 				    id);
310 			fmt = " %s";
311 		} else {
312 			(void)printf(fmt, id);
313 			fmt = " %u";
314 		}
315 		lastid = id;
316 	}
317 	(void)printf("\n");
318 }
319 
320 struct passwd *
321 who(char *u)
322 {
323 	struct passwd *pw;
324 	long id;
325 	char *ep;
326 
327 	/*
328 	 * Translate user argument into a pw pointer.  First, try to
329 	 * get it as specified.  If that fails, try it as a number.
330 	 */
331 	if ((pw = getpwnam(u)))
332 		return(pw);
333 	id = strtol(u, &ep, 10);
334 	if (*u && !*ep && (pw = getpwuid(id)))
335 		return(pw);
336 	errx(1, "%s: no such user", u);
337 	/* NOTREACHED */
338 }
339 
340 void
341 pline(struct passwd *pw)
342 {
343 	u_int rid;
344 
345 	if (!pw) {
346 		if ((pw = getpwuid(rid = getuid())) == NULL)
347 			err(1, "getpwuid");
348 	}
349 
350 	(void)printf("%s:%s:%d:%d:%s:%ld:%ld:%s:%s:%s\n", pw->pw_name,
351 			pw->pw_passwd, pw->pw_uid, pw->pw_gid, pw->pw_class,
352 			(long)pw->pw_change, (long)pw->pw_expire, pw->pw_gecos,
353 			pw->pw_dir, pw->pw_shell);
354 }
355 
356 
357 void
358 usage(void)
359 {
360 
361 	if (isgroups)
362 		(void)fprintf(stderr, "usage: groups [user]\n");
363 	else if (iswhoami)
364 		(void)fprintf(stderr, "usage: whoami\n");
365 	else
366 		(void)fprintf(stderr, "%s\n%s\n%s\n%s\n%s\n%s\n",
367 		    "usage: id [user]",
368 		    "       id -G [-n] [user]",
369 		    "       id -P [user]",
370 		    "       id -g [-nr] [user]",
371 		    "       id -p [user]",
372 		    "       id -u [-nr] [user]");
373 	exit(1);
374 }
375