2.11BSD#431 - /usr/src/lib/libc/gen/getlogin.c

   1: /*
   2:  * Copyright (c) 1988, 1993
   3:  *	The Regents of the University of California.  All rights reserved.
   4:  *
   5:  * Redistribution and use in source and binary forms, with or without
   6:  * modification, are permitted provided that the following conditions
   7:  * are met:
   8:  * 1. Redistributions of source code must retain the above copyright
   9:  *    notice, this list of conditions and the following disclaimer.
  10:  * 2. Redistributions in binary form must reproduce the above copyright
  11:  *    notice, this list of conditions and the following disclaimer in the
  12:  *    documentation and/or other materials provided with the distribution.
  13:  * 3. All advertising materials mentioning features or use of this software
  14:  *    must display the following acknowledgement:
  15:  *	This product includes software developed by the University of
  16:  *	California, Berkeley and its contributors.
  17:  * 4. Neither the name of the University 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 REGENTS 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 REGENTS 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: #if defined(LIBC_SCCS) && !defined(lint)
  35: static char sccsid[] = "@(#)getlogin.c	8.1.1 (2.11BSD) 1997.9.23";
  36: #endif /* LIBC_SCCS and not lint */
  37: 
  38: #include <sys/param.h>
  39: #include <pwd.h>
  40: #include <utmp.h>
  41: #include <stdio.h>
  42: #include <string.h>
  43: #include <unistd.h>
  44: 
  45: int _logname_valid;     /* known to setlogin() */
  46: 
  47: char *
  48: getlogin()
  49: {
  50:     static char logname[MAXLOGNAME + 1];
  51: 
  52:     if (_logname_valid == 0) {
  53:         if (_getlogin(logname, sizeof(logname) - 1) < 0)
  54:             return ((char *)NULL);
  55:         _logname_valid = 1;
  56:     }
  57:     return (*logname ? logname : (char *)NULL);
  58: }

Defined functions

Defined variables