107 lines
3.3 KiB
C
107 lines
3.3 KiB
C
/****************************************************************************
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*
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* Open Watcom Project
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*
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* Portions Copyright (c) 1983-2002 Sybase, Inc. All Rights Reserved.
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*
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* ========================================================================
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*
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* This file contains Original Code and/or Modifications of Original
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* Code as defined in and that are subject to the Sybase Open Watcom
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* Public License version 1.0 (the 'License'). You may not use this file
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* except in compliance with the License. BY USING THIS FILE YOU AGREE TO
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* ALL TERMS AND CONDITIONS OF THE LICENSE. A copy of the License is
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* provided with the Original Code and Modifications, and is also
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* available at www.sybase.com/developer/opensource.
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*
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* The Original Code and all software distributed under the License are
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* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
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* EXPRESS OR IMPLIED, AND SYBASE AND ALL CONTRIBUTORS HEREBY DISCLAIM
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* ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR
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* NON-INFRINGEMENT. Please see the License for the specific language
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* governing rights and limitations under the License.
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*
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* ========================================================================
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*
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* Description: Implementation of gets_s().
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*
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****************************************************************************/
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#include "variety.h"
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#include "saferlib.h"
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#include <stdio.h>
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_WCRTLINK extern char *gets_s( char *s, rsize_t n )
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/*************************************************/
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{
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int c;
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char *cs;
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rsize_t len;
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unsigned oflag;
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/* Check runtime constraint: s shall not be a null pointer */
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if( ! __check_constraint_nullptr( s ) ) {
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/* Just trigger the constraint handler if necessary */
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}
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/* Check runtime constraint: n shall not be zero nor
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greater than RSIZE_MAX */
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if( ! __check_constraint_zero( n )
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|| ! __check_constraint_maxsize( n ) ) {
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n = 0;
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}
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/* Filter out stream error and EOF status during this function */
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oflag = stdin->_flag & (_SFERR | _EOF);
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stdin->_flag &= ~(_SFERR | _EOF);
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cs = s;
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len = n;
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/*
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Read data until any of following conditions is met:
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- Received EOF
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- Read error
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- New line character received
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*/
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while( (c = getc( stdin )) != EOF
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&& (c != '\n') ) {
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if( cs && len ) {
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*cs++ = c;
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len--;
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}
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}
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/* Post-process runtime constraints, return NULL when catched */
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if( s == NULL || n == 0) {
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stdin->_flag |= oflag;
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return( NULL );
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}
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/* After this point, it is assumed that s is valid and
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contains at least one character */
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/* Catch too small buffer and I/O error */
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if( ! __check_constraint_toosmall( s, len )
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|| ferror( stdin ) ) {
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stdin->_flag |= oflag;
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*s = 0;
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return( NULL );
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}
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/* Restore stream error states if they were present previously */
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stdin->_flag |= oflag;
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/* If we got EOF and didn't get any characters, return NULL */
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if( c == EOF && cs == s ) {
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*s = 0;
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return( NULL );
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}
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/* Terminate string */
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*cs = 0;
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return( s );
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}
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