xref: /onnv-gate/usr/src/lib/libbc/libc/stdio/common/gets.c (revision 722:636b850d4ee9)
10Sstevel@tonic-gate /*
20Sstevel@tonic-gate  * CDDL HEADER START
30Sstevel@tonic-gate  *
40Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
50Sstevel@tonic-gate  * Common Development and Distribution License, Version 1.0 only
60Sstevel@tonic-gate  * (the "License").  You may not use this file except in compliance
70Sstevel@tonic-gate  * with the License.
80Sstevel@tonic-gate  *
90Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
100Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
110Sstevel@tonic-gate  * See the License for the specific language governing permissions
120Sstevel@tonic-gate  * and limitations under the License.
130Sstevel@tonic-gate  *
140Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
150Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
160Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
170Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
180Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
190Sstevel@tonic-gate  *
200Sstevel@tonic-gate  * CDDL HEADER END
210Sstevel@tonic-gate  */
220Sstevel@tonic-gate /*      Copyright (c) 1984 AT&T */
230Sstevel@tonic-gate /*        All Rights Reserved   */
240Sstevel@tonic-gate 
25*722Smuffin #pragma ident	"%Z%%M%	%I%	%E% SMI"
260Sstevel@tonic-gate 
270Sstevel@tonic-gate /*LINTLIBRARY*/
280Sstevel@tonic-gate /*
290Sstevel@tonic-gate  * This version reads directly from the buffer rather than looping on getc.
300Sstevel@tonic-gate  * Ptr args aren't checked for NULL because the program would be a
310Sstevel@tonic-gate  * catastrophic mess anyway.  Better to abort than just to return NULL.
320Sstevel@tonic-gate  */
330Sstevel@tonic-gate #include <stdio.h>
340Sstevel@tonic-gate #include "stdiom.h"
35*722Smuffin #include <memory.h>
360Sstevel@tonic-gate 
370Sstevel@tonic-gate extern int _filbuf();
380Sstevel@tonic-gate 
390Sstevel@tonic-gate char *
gets(char * ptr)40*722Smuffin gets(char *ptr)
410Sstevel@tonic-gate {
420Sstevel@tonic-gate 	char *p, *ptr0 = ptr;
43*722Smuffin 	int n;
440Sstevel@tonic-gate 
450Sstevel@tonic-gate 	for ( ; ; ) {
460Sstevel@tonic-gate 		if (stdin->_cnt <= 0) { /* empty buffer */
470Sstevel@tonic-gate 			if (_filbuf(stdin) == EOF) {
480Sstevel@tonic-gate 				if (ptr0 == ptr)
490Sstevel@tonic-gate 					return (NULL);
500Sstevel@tonic-gate 				break; /* no more data */
510Sstevel@tonic-gate 			}
520Sstevel@tonic-gate 			stdin->_ptr--;
530Sstevel@tonic-gate 			stdin->_cnt++;
540Sstevel@tonic-gate 		}
550Sstevel@tonic-gate 		n = stdin->_cnt;
560Sstevel@tonic-gate 		if ((p = memccpy(ptr, (char *) stdin->_ptr, '\n', n)) != NULL)
570Sstevel@tonic-gate 			n = p - ptr;
580Sstevel@tonic-gate 		ptr += n;
590Sstevel@tonic-gate 		stdin->_cnt -= n;
600Sstevel@tonic-gate 		stdin->_ptr += n;
610Sstevel@tonic-gate 		_BUFSYNC(stdin);
620Sstevel@tonic-gate 		if (p != NULL) { /* found '\n' in buffer */
630Sstevel@tonic-gate 			ptr--; /* step back over '\n' */
640Sstevel@tonic-gate 			break;
650Sstevel@tonic-gate 		}
660Sstevel@tonic-gate 	}
670Sstevel@tonic-gate 	*ptr = '\0';
680Sstevel@tonic-gate 	return (ptr0);
690Sstevel@tonic-gate }
70