1 /* 2 * Copyright (c) 1997 - 1999 Kungliga Tekniska H�gskolan 3 * (Royal Institute of Technology, Stockholm, Sweden). 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * 3. Neither the name of the Institute nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #ifdef HAVE_CONFIG_H 35 #include <config.h> 36 RCSID("$Id: get_default_username.c,v 1.3 1999/12/02 16:58:46 joda Exp $"); 37 #endif /* HAVE_CONFIG_H */ 38 39 #include "roken.h" 40 41 /* 42 * Try to return what should be considered the default username or 43 * NULL if we can't guess at all. 44 */ 45 46 const char * 47 get_default_username (void) 48 { 49 const char *user; 50 51 user = getenv ("USER"); 52 if (user == NULL) 53 user = getenv ("LOGNAME"); 54 if (user == NULL) 55 user = getenv ("USERNAME"); 56 57 #if defined(HAVE_GETLOGIN) && !defined(POSIX_GETLOGIN) 58 if (user == NULL) { 59 user = (const char *)getlogin (); 60 if (user != NULL) 61 return user; 62 } 63 #endif 64 #ifdef HAVE_PWD_H 65 { 66 uid_t uid = getuid (); 67 struct passwd *pwd; 68 69 if (user != NULL) { 70 pwd = k_getpwnam (user); 71 if (pwd != NULL && pwd->pw_uid == uid) 72 return user; 73 } 74 pwd = k_getpwuid (uid); 75 if (pwd != NULL) 76 return pwd->pw_name; 77 } 78 #endif 79 return user; 80 } 81