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Diffstat (limited to 'src/id.c')
| -rw-r--r-- | src/id.c | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/src/id.c b/src/id.c new file mode 100644 index 0000000..4952109 --- /dev/null +++ b/src/id.c @@ -0,0 +1,172 @@ +/* + * 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; +} + |