usr/src/lib/libbc/libc/stdio/common/cuserid.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*      Copyright (c) 1984 AT&T */
  23 /*        All Rights Reserved   */
  24
  25 #pragma ident   "%Z%%M% %I%     %E% SMI"  /* from S5R2 1.3 */
  26
  27 /*LINTLIBRARY*/
  28 #include <stdio.h>
  29 #include <pwd.h>
  30
  31 extern char *strcpy(), *getlogin();
  32 extern int getuid();
  33 extern struct passwd *getpwuid();
  34 static char res[L_cuserid];
  35
  36 char *
  37 cuserid(s)
  38 char    *s;
  39 {
  40         register struct passwd *pw;
  41         register char *p;
  42
  43         if (s == NULL)
  44                 s = res;
  45         p = getlogin();
  46         if (p != NULL)
  47                 return (strcpy(s, p));
  48         pw = getpwuid(getuid());
  49         endpwent();
  50         if (pw != NULL)
  51                 return (strcpy(s, pw->pw_name));
  52         *s = '\0';
  53         return (NULL);
  54 }