xref: /titanic_51/usr/src/lib/libbc/libc/stdio/common/gets.c (revision 5d54f3d8999eac1762fe0a8c7177d20f1f201fae)
17c478bd9Sstevel@tonic-gate /*
27c478bd9Sstevel@tonic-gate  * CDDL HEADER START
37c478bd9Sstevel@tonic-gate  *
47c478bd9Sstevel@tonic-gate  * The contents of this file are subject to the terms of the
57c478bd9Sstevel@tonic-gate  * Common Development and Distribution License, Version 1.0 only
67c478bd9Sstevel@tonic-gate  * (the "License").  You may not use this file except in compliance
77c478bd9Sstevel@tonic-gate  * with the License.
87c478bd9Sstevel@tonic-gate  *
97c478bd9Sstevel@tonic-gate  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
107c478bd9Sstevel@tonic-gate  * or http://www.opensolaris.org/os/licensing.
117c478bd9Sstevel@tonic-gate  * See the License for the specific language governing permissions
127c478bd9Sstevel@tonic-gate  * and limitations under the License.
137c478bd9Sstevel@tonic-gate  *
147c478bd9Sstevel@tonic-gate  * When distributing Covered Code, include this CDDL HEADER in each
157c478bd9Sstevel@tonic-gate  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
167c478bd9Sstevel@tonic-gate  * If applicable, add the following below this CDDL HEADER, with the
177c478bd9Sstevel@tonic-gate  * fields enclosed by brackets "[]" replaced with your own identifying
187c478bd9Sstevel@tonic-gate  * information: Portions Copyright [yyyy] [name of copyright owner]
197c478bd9Sstevel@tonic-gate  *
207c478bd9Sstevel@tonic-gate  * CDDL HEADER END
217c478bd9Sstevel@tonic-gate  */
227c478bd9Sstevel@tonic-gate /*      Copyright (c) 1984 AT&T */
237c478bd9Sstevel@tonic-gate /*        All Rights Reserved   */
247c478bd9Sstevel@tonic-gate 
25*5d54f3d8Smuffin #pragma ident	"%Z%%M%	%I%	%E% SMI"
267c478bd9Sstevel@tonic-gate 
277c478bd9Sstevel@tonic-gate /*LINTLIBRARY*/
287c478bd9Sstevel@tonic-gate /*
297c478bd9Sstevel@tonic-gate  * This version reads directly from the buffer rather than looping on getc.
307c478bd9Sstevel@tonic-gate  * Ptr args aren't checked for NULL because the program would be a
317c478bd9Sstevel@tonic-gate  * catastrophic mess anyway.  Better to abort than just to return NULL.
327c478bd9Sstevel@tonic-gate  */
337c478bd9Sstevel@tonic-gate #include <stdio.h>
347c478bd9Sstevel@tonic-gate #include "stdiom.h"
35*5d54f3d8Smuffin #include <memory.h>
367c478bd9Sstevel@tonic-gate 
377c478bd9Sstevel@tonic-gate extern int _filbuf();
387c478bd9Sstevel@tonic-gate 
397c478bd9Sstevel@tonic-gate char *
40*5d54f3d8Smuffin gets(char *ptr)
417c478bd9Sstevel@tonic-gate {
427c478bd9Sstevel@tonic-gate 	char *p, *ptr0 = ptr;
43*5d54f3d8Smuffin 	int n;
447c478bd9Sstevel@tonic-gate 
457c478bd9Sstevel@tonic-gate 	for ( ; ; ) {
467c478bd9Sstevel@tonic-gate 		if (stdin->_cnt <= 0) { /* empty buffer */
477c478bd9Sstevel@tonic-gate 			if (_filbuf(stdin) == EOF) {
487c478bd9Sstevel@tonic-gate 				if (ptr0 == ptr)
497c478bd9Sstevel@tonic-gate 					return (NULL);
507c478bd9Sstevel@tonic-gate 				break; /* no more data */
517c478bd9Sstevel@tonic-gate 			}
527c478bd9Sstevel@tonic-gate 			stdin->_ptr--;
537c478bd9Sstevel@tonic-gate 			stdin->_cnt++;
547c478bd9Sstevel@tonic-gate 		}
557c478bd9Sstevel@tonic-gate 		n = stdin->_cnt;
567c478bd9Sstevel@tonic-gate 		if ((p = memccpy(ptr, (char *) stdin->_ptr, '\n', n)) != NULL)
577c478bd9Sstevel@tonic-gate 			n = p - ptr;
587c478bd9Sstevel@tonic-gate 		ptr += n;
597c478bd9Sstevel@tonic-gate 		stdin->_cnt -= n;
607c478bd9Sstevel@tonic-gate 		stdin->_ptr += n;
617c478bd9Sstevel@tonic-gate 		_BUFSYNC(stdin);
627c478bd9Sstevel@tonic-gate 		if (p != NULL) { /* found '\n' in buffer */
637c478bd9Sstevel@tonic-gate 			ptr--; /* step back over '\n' */
647c478bd9Sstevel@tonic-gate 			break;
657c478bd9Sstevel@tonic-gate 		}
667c478bd9Sstevel@tonic-gate 	}
677c478bd9Sstevel@tonic-gate 	*ptr = '\0';
687c478bd9Sstevel@tonic-gate 	return (ptr0);
697c478bd9Sstevel@tonic-gate }
70