00001 /*
00002     Display real and effective user and group IDs
00003     AUP2, Sec. 5.11
00004 
00005     Copyright 2003 by Marc J. Rochkind. All rights reserved.
00006     May be copied only for purposes and under conditions described
00007     on the Web page www.basepath.com/aup/copyright.htm.
00008 
00009     The Example Files are provided "as is," without any warranty;
00010     without even the implied warranty of merchantability or fitness
00011     for a particular purpose. The author and his publisher are not
00012     responsible for any damages, direct or incidental, resulting
00013     from the use or non-use of these Example Files.
00014 
00015     The Example Files may contain defects, and some contain deliberate
00016     coding mistakes that were included for educational reasons.
00017     You are responsible for determining if and how the Example Files
00018     are to be used.
00019 
00020 */
00021 #include "defs.h"
00022 #include <pwd.h>
00023 #include <grp.h>
00024 
00025 /*[uidgrp]*/
00026 int main(void)
00027 {
00028     uid_t uid;
00029     gid_t gid;
00030     struct passwd *pwd;
00031     struct group *grp;
00032 
00033     uid = getuid();
00034     ec_null( pwd = getpwuid(uid) )
00035     printf("Real user = %ld (%s)\n", (long)uid, pwd->pw_name);
00036 
00037     uid = geteuid();
00038     ec_null( pwd = getpwuid(uid) )
00039     printf("Effective user = %ld (%s)\n", (long)uid, pwd->pw_name);
00040 
00041     gid = getgid();
00042     ec_null( grp = getgrgid(gid) )
00043     printf("Real group = %ld (%s)\n", (long)gid, grp->gr_name);
00044 
00045     gid = getegid();
00046     ec_null( grp = getgrgid(gid) )
00047     printf("Effective group = %ld (%s)\n", (long)gid, grp->gr_name);
00048 
00049     exit(EXIT_SUCCESS);
00050 
00051 EC_CLEANUP_BGN
00052     exit(EXIT_FAILURE);
00053 EC_CLEANUP_END
00054 }
00055 /*[]*/
c5/uidgrp.c
