Files
harbour-core/harbour/source/tools/ascpos.c
1999-08-01 19:59:10 +00:00

74 lines
1.9 KiB
C

/*
* $Id$
*/
/*
* GT CLIPPER STANDARD HEADER
*
* File......: ascpos.c
* Author....: Andy M Leighton
* BBS.......: The Dark Knight Returns
* Net/Node..: 050/069
* User Name.: Andy Leighton
* Date......: 23/05/93
* Revision..: 1.00
*
* This is an original work by Andy Leighton and is placed in the
* public domain.
*/
/*
* $DOC$
* $FUNCNAME$
* GT_ASCPOS()
* $CATEGORY$
* String
* $ONELINER$
* Return the ascii value of a specified character in a string
* $SYNTAX$
* GT_Ascpos(<cStr>, <nPos>) --> nAscVal
* $ARGUMENTS$
* <cStr> - The string
* <nPos> - The position in <cStr>
* $RETURNS$
* nAscVal - The ascii value of substr(<cStr>, <nPos>, 1)
* $DESCRIPTION$
* Return the ascii value of a specified character in a string
* Equivalent (but much faster) to
* asc(substr(cStr, nPos, 1)
*
* NOTE:
* invalid parameters will return -1
* nPos > len(cStr) will return -2
*
* This last behaviour is different to the Funcky function of the
* same name. I changed the behaviour because some of the strings
* I process contain embedded NULs.
* $EXAMPLES$
* ? gt_ascpos("the cat sat on the mat", 3) // prints e
* $END$
*/
#include "extend.h"
HARBOUR HB_GT_ASCPOS( void )
{
char *s;
int p;
if (ISCHAR(1) && ISNUM(2)) {
s = hb_parc(1);
p = hb_parni(2);
p--; /* decrement p to adjust for c strings */
/* starting at position 0 */
if (p > hb_parclen(1)) /* oh oh p > length of passed string */
hb_retni(-2); /* error -2 */
else
hb_retni((int) s[p]); /* return ascii code of appropriate */
/* character in string */
} else {
hb_retni(-1); /* parameter mismatch - error -1 */
}
}