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/*
* SPDX-FileCopyrightText: 1991 - 1994, Julianne Frances Haugh
* SPDX-FileCopyrightText: 1996 - 2000, Marek Michałkiewicz
* SPDX-FileCopyrightText: 2001 - 2006, Tomasz Kłoczko
* SPDX-FileCopyrightText: 2007 - 2008, Nicolas François
*
* SPDX-License-Identifier: BSD-3-Clause
*/
/*
* 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 "alloc.h"
#include "defines.h"
/* local function prototypes */
static void usage (void);
static void usage (void)
{
(void) fputs (_("Usage: id [-a]\n"), stderr);
exit (EXIT_FAILURE);
}
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.
*/
GETGROUPS_T *groups;
int ngroups;
bool aflg = 0;
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);
groups = MALLOC(sys_ngroups, GETGROUPS_T);
/*
* 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;
}
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);
}
}
/*
* 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);
/*
* Finish off the line.
*/
(void) putchar ('\n');
return EXIT_SUCCESS;
}
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