1/* $NetBSD: get_default_username.c,v 1.1.1.1 2011/04/13 18:15:41 elric Exp $ */ 2 3/* 4 * Copyright (c) 1997 - 1999 Kungliga Tekniska Högskolan 5 * (Royal Institute of Technology, Stockholm, Sweden). 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * 3. Neither the name of the Institute nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36#include <config.h> 37 38#include <krb5/roken.h> 39 40/* 41 * Try to return what should be considered the default username or 42 * NULL if we can't guess at all. 43 */ 44 45ROKEN_LIB_FUNCTION const char * ROKEN_LIB_CALL 46get_default_username (void) 47{ 48 const char *user; 49 50 user = getenv ("USER"); 51 if (user == NULL) 52 user = getenv ("LOGNAME"); 53 if (user == NULL) 54 user = getenv ("USERNAME"); 55 56#if defined(HAVE_GETLOGIN) && !defined(POSIX_GETLOGIN) 57 if (user == NULL) { 58 user = (const char *)getlogin (); 59 if (user != NULL) 60 return user; 61 } 62#endif 63#ifdef HAVE_PWD_H 64 { 65 uid_t uid = getuid (); 66 struct passwd *pwd; 67 68 if (user != NULL) { 69 pwd = k_getpwnam (user); 70 if (pwd != NULL && pwd->pw_uid == uid) 71 return user; 72 } 73 pwd = k_getpwuid (uid); 74 if (pwd != NULL) 75 return pwd->pw_name; 76 } 77#endif 78#ifdef _WIN32 79 /* TODO: We can call GetUserNameEx() and figure out a 80 username. However, callers do not free the return value of this 81 function. */ 82#endif 83 84 return user; 85} 86