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-rw-r--r--src/id.c172
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diff --git a/src/id.c b/src/id.c
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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 "defines.h"
+/* local function prototypes */
+static void usage (void);
+
+static void usage (void)
+{
+ (void) fputs (_("Usage: id [-a]\n"), stderr);
+ 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.
+ */
+ 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 = (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;
+ }
+ }
+
+ 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;
+}
+