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      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 (the "License").
      6  * You may not use this file except in compliance with the License.
      7  *
      8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
      9  * or http://www.opensolaris.org/os/licensing.
     10  * See the License for the specific language governing permissions
     11  * and limitations under the License.
     12  *
     13  * When distributing Covered Code, include this CDDL HEADER in each
     14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
     15  * If applicable, add the following below this CDDL HEADER, with the
     16  * fields enclosed by brackets "[]" replaced with your own identifying
     17  * information: Portions Copyright [yyyy] [name of copyright owner]
     18  *
     19  * CDDL HEADER END
     20  */
     21 
     22 /*
     23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
     24  * Use is subject to license terms.
     25  */
     26 
     27 /*	Copyright (c) 1988 AT&T	*/
     28 /*	  All Rights Reserved  	*/
     29 
     30 #pragma ident	"%Z%%M%	%I%	%E% SMI"
     31 
     32 #pragma weak _cuserid = cuserid
     33 
     34 #include "lint.h"
     35 #include <stdio.h>
     36 #include <pwd.h>
     37 #include <string.h>
     38 #include <stdlib.h>
     39 #include <unistd.h>
     40 #include <pthread.h>
     41 
     42 static char res[L_cuserid];
     43 
     44 char *
     45 cuserid(char *s)
     46 {
     47 	struct passwd *pw;
     48 	struct passwd pwd;
     49 	char buffer[BUFSIZ];
     50 	char utname[L_cuserid];
     51 	char *p;
     52 	int cancel_state;
     53 
     54 	/*
     55 	 * The UNIX98 Posix conformance test suite requires
     56 	 * cuserid() to not be a cancellation point.
     57 	 */
     58 	(void) pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, &cancel_state);
     59 
     60 	if (s == NULL)
     61 		s = res;
     62 	if ((p = getlogin_r(utname, L_cuserid)) != NULL) {
     63 		(void) strlcpy(s, p, L_cuserid);
     64 	} else if ((pw = getpwuid_r(getuid(), &pwd, buffer, BUFSIZ)) != NULL) {
     65 		(void) strlcpy(s, pw->pw_name, L_cuserid);
     66 	} else {
     67 		*s = '\0';
     68 		s = NULL;
     69 	}
     70 
     71 	(void) pthread_setcancelstate(cancel_state, NULL);
     72 	return (s);
     73 }
     74