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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 #include "lint.h"
     33 #include "file64.h"
     34 #include "mtlib.h"
     35 #include <sys/types.h>
     36 #include <stdio.h>
     37 #include <memory.h>
     38 #include <thread.h>
     39 #include <synch.h>
     40 #include <errno.h>
     41 #include "stdiom.h"
     42 #include "mse.h"
     43 
     44 /* read a single line from stdin, replace the '\n' with '\0' */
     45 char *
     46 gets(char *buf)
     47 {
     48 	char *ptr = buf;
     49 	ssize_t n;
     50 	char *p;
     51 	Uchar *bufend;
     52 	rmutex_t *lk;
     53 
     54 	FLOCKFILE(lk, stdin);
     55 
     56 	_SET_ORIENTATION_BYTE(stdin);
     57 
     58 	if (!(stdin->_flag & (_IOREAD | _IORW))) {
     59 		errno = EBADF;
     60 		FUNLOCKFILE(lk);
     61 		return (0);
     62 	}
     63 
     64 	if (stdin->_base == NULL) {
     65 		if ((bufend = _findbuf(stdin)) == 0) {
     66 			FUNLOCKFILE(lk);
     67 			return (0);
     68 		}
     69 	}
     70 	else
     71 		bufend = _bufend(stdin);
     72 
     73 	for (;;)	/* until get a '\n' */
     74 	{
     75 		if (stdin->_cnt <= 0)	/* empty buffer */
     76 		{
     77 			if (__filbuf(stdin) != EOF) {
     78 				stdin->_ptr--;	/* put back the character */
     79 				stdin->_cnt++;
     80 			} else if (ptr == buf) {  /* never read anything */
     81 				FUNLOCKFILE(lk);
     82 				return (0);
     83 			} else
     84 				break;		/* nothing left to read */
     85 		}
     86 		n = stdin->_cnt;
     87 		if ((p = (char *)memccpy(ptr, (char *)stdin->_ptr, '\n',
     88 		    (size_t)n)) != 0)
     89 			n = p - ptr;
     90 		ptr += n;
     91 		stdin->_cnt -= n;
     92 		stdin->_ptr += n;
     93 		if (_needsync(stdin, bufend))
     94 			_bufsync(stdin, bufend);
     95 		if (p != 0) /* found a '\n' */
     96 		{
     97 			ptr--;	/* step back over the '\n' */
     98 			break;
     99 		}
    100 	}
    101 	*ptr = '\0';
    102 	FUNLOCKFILE(lk);
    103 	return (buf);
    104 }
    105