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id.c revision 1.20 
      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