/*
 * $Id$
 */

/*
 * File......: findith.prg
 * Author....: David Husnian
 * CIS ID....: ?
 *
 * This is an original work by David Husnian and is placed in the
 * public domain.
 *
 * Modification history:
 * ---------------------
 *
 *    Rev 1.2   15 Aug 1991 23:03:36   GLENN
 * Forest Belt proofread/edited/cleaned up doc
 *
 *    Rev 1.1   14 Jun 1991 19:51:52   GLENN
 * Minor edit to file header
 *
 *    Rev 1.0   01 Apr 1991 01:01:22   GLENN
 * Nanforum Toolkit
 *
 */

#define IS_NOT_LOGICAL(x)               (VALTYPE(x) != "L")
#define MAKE_UPPER(cString)             (cString := UPPER(cString))
#define NULL                            ""

#ifdef FT_TEST
  FUNCTION MAIN( cCk, cStr, nOcc, xCase )
     LOCAL nFind
     if pcount() != 4
        QOut( "usage: findith cCk cStr nOcc xCase")
        quit
     endif

     xCase := iif( xCase == "Y", .t., .f. )
     nOcc  := val(nOcc)
     QOut( iif( xCase, "Ignoring ", "Observing ") + "case:" )

     QOut( cStr )
     nFind := FT_FINDITH( cCk, cStr, nOcc, xCase )
     QOut( iif( nFind > 0, space( nFind - 1) + "^" , "Not found" ) )
  RETURN nil
#endif

FUNCTION FT_FINDITH(cCheckFor,cCheckIn,nWhichOccurrence,lIgnoreCase)

   LOCAL nIthOccurrence

                                        // Is Case Sensitivity Important??
   IF IS_NOT_LOGICAL(lIgnoreCase) .OR. ;
      lIgnoreCase

      MAKE_UPPER(cCheckFor)             // No, Force Everything to Uppercase
      MAKE_UPPER(cCheckIn)

   ENDIF                                // IS_NOT_LOGICAL(lIgnoreCase) or
                                        // lIgnoreCase

   RETURN iif(nWhichOccurrence == 1, ;
             AT(cCheckFor, cCheckIn), ;
             iif((nIthOccurrence := AT(cCheckFor, ;
                                     STRTRAN(cCheckIn, cCheckFor, ;
                                             NULL, 1, ;
                                             nWhichOccurrence-1))) == 0, ;
                0, ;
                nIthOccurrence + ((nWhichOccurrence - 1) * LEN(cCheckFor))))