kolibrios/programs/develop/open watcom/trunk/clib/string/fstrspn.c

/****************************************************************************
*
*                            Open Watcom Project
*
*    Portions Copyright (c) 1983-2002 Sybase, Inc. All Rights Reserved.
*
*  ========================================================================
*
*    This file contains Original Code and/or Modifications of Original
*    Code as defined in and that are subject to the Sybase Open Watcom
*    Public License version 1.0 (the 'License'). You may not use this file
*    except in compliance with the License. BY USING THIS FILE YOU AGREE TO
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*    available at www.sybase.com/developer/opensource.
*
*    The Original Code and all software distributed under the License are
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* Description:  WHEN YOU FIGURE OUT WHAT THIS FILE DOES, PLEASE
*               DESCRIBE IT HERE!
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****************************************************************************/


#include "variety.h"
#include <string.h>
#include "setbits.h"

/*  The strspn function computes the length of the initial segment of the
    string pointed to by str which consists entirely of characters from
    the string pointed to by charset.
*/

_WCRTLINK size_t _fstrspn( const char _WCFAR *str, const char _WCFAR *charset )
{
    unsigned /*char*/ tc;
    unsigned char vector[32];
    size_t len;

    __fsetbits( vector, charset );
    len = 0;
    for( ; tc = (unsigned char) *str; ++str, ++len ) {
        /* quit if we find any char not in charset */
        if( ( vector[ tc >> 3 ] & _Bits[ tc & 0x07 ] ) == 0 )  break;
    }
    return( len );
}