summaryrefslogtreecommitdiff
path: root/src/id.c
blob: 4462ae098438e016be25002459f9739e49b00251 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
/*
 * Copyright (c) 1991 - 1994, Julianne Frances Haugh
 * Copyright (c) 1996 - 2000, Marek Michałkiewicz
 * Copyright (c) 2001 - 2006, Tomasz Kłoczko
 * Copyright (c) 2007 - 2008, Nicolas François
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the copyright holders or contributors may not be used to
 *    endorse or promote products derived from this software without
 *    specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
 * PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT
 * HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * id - print current process user identification information
 *
 *	Print the current process identifiers. This includes the
 *	UID, GID, effective-UID and effective-GID. Optionally print
 *	the concurrent group set if the current system supports it.
 */

#include <config.h>

#ident "$Id$"

#include <grp.h>
#include <pwd.h>
#include <stdio.h>
#include <sys/types.h>
#include "defines.h"
/* local function prototypes */
static void usage (void);

static void usage (void)
{
#ifdef HAVE_GETGROUPS
	(void) fputs (_("Usage: id [-a]\n"), stderr);
#else
	(void) fputs (_("Usage: id\n"), stderr);
#endif
	exit (EXIT_FAILURE);
}

 /*ARGSUSED*/ int main (int argc, char **argv)
{
	uid_t ruid, euid;
	gid_t rgid, egid;
	long sys_ngroups;

/*
 * This block of declarations is particularly strained because of several
 * different ways of doing concurrent groups. Old BSD systems used int for
 * gid's, but short for the type passed to getgroups(). Newer systems use
 * gid_t for everything. Some systems have a small and fixed NGROUPS,
 * usually about 16 or 32. Others use bigger values.
 */
#ifdef HAVE_GETGROUPS
	GETGROUPS_T *groups;
	int ngroups;
	bool aflg = 0;
#endif
	struct passwd *pw;
	struct group *gr;

	(void) setlocale (LC_ALL, "");
	(void) bindtextdomain (PACKAGE, LOCALEDIR);
	(void) textdomain (PACKAGE);

	/*
	 * Dynamically get the maximum number of groups from system, instead
	 * of using the symbolic constant NGROUPS_MAX. This ensures that the
	 * group limit is not hard coded into the binary, so it will still
	 * work if the system library is recompiled.
	 */
	sys_ngroups = sysconf (_SC_NGROUPS_MAX);
#ifdef HAVE_GETGROUPS
	groups = (GETGROUPS_T *) malloc (sizeof (GETGROUPS_T) * sys_ngroups);
	/*
	 * See if the -a flag has been given to print out the concurrent
	 * group set.
	 */

	if (argc > 1) {
		if ((argc > 2) || (strcmp (argv[1], "-a") != 0)) {
			usage ();
		} else {
			aflg = true;
		}
	}
#else
	if (argc > 1) {
		usage ();
	}
#endif

	ruid = getuid ();
	euid = geteuid ();
	rgid = getgid ();
	egid = getegid ();

	/*
	 * Print out the real user ID and group ID. If the user or group
	 * does not exist, just give the numerical value.
	 */

	pw = getpwuid (ruid); /* local, no need for xgetpwuid */
	if (NULL != pw) {
		(void) printf ("UID=%lu(%s)",
		               (unsigned long) ruid, pw->pw_name);
	} else {
		(void) printf ("UID=%lu", (unsigned long) ruid);
	}

	gr = getgrgid (rgid);; /* local, no need for xgetgrgid */
	if (NULL != gr) {
		(void) printf (" GID=%lu(%s)",
		               (unsigned long) rgid, gr->gr_name);
	} else {
		(void) printf (" GID=%lu", (unsigned long) rgid);
	}

	/*
	 * Print out the effective user ID and group ID if they are
	 * different from the real values.
	 */

	if (ruid != euid) {
		pw = getpwuid (euid); /* local, no need for xgetpwuid */
		if (NULL != pw) {
			(void) printf (" EUID=%lu(%s)",
			               (unsigned long) euid, pw->pw_name);
		} else {
			(void) printf (" EUID=%lu", (unsigned long) euid);
		}
	}
	if (rgid != egid) {
		gr = getgrgid (egid); /* local, no need for xgetgrgid */
		if (NULL != gr) {
			(void) printf (" EGID=%lu(%s)",
			               (unsigned long) egid, gr->gr_name);
		} else {
			(void) printf (" EGID=%lu", (unsigned long) egid);
		}
	}
#ifdef HAVE_GETGROUPS
	/*
	 * Print out the concurrent group set if the user has requested it.
	 * The group numbers will be printed followed by their names.
	 */
	if (aflg && (ngroups = getgroups (sys_ngroups, groups)) != -1) {
		int i;

		/*
		 * Start off the group message. It will be of the format
		 *
		 *      groups=###(aaa),###(aaa),###(aaa)
		 *
		 * where "###" is a numerical value and "aaa" is the
		 * corresponding name for each respective numerical value.
		 */
		(void) puts (_(" groups="));
		for (i = 0; i < ngroups; i++) {
			if (0 != i)
				(void) putchar (',');

			/* local, no need for xgetgrgid */
			gr = getgrgid (groups[i]);
			if (NULL != gr) {
				(void) printf ("%lu(%s)",
				               (unsigned long) groups[i],
				               gr->gr_name);
			} else {
				(void) printf ("%lu",
				               (unsigned long) groups[i]);
			}
		}
	}
	free (groups);
#endif

	/*
	 * Finish off the line.
	 */
	(void) putchar ('\n');

	return EXIT_SUCCESS;
}