$CPU 8086          ' make compatible with XT systems
$LIB ALL OFF       ' turn off all PowerBASIC libraries
$ERROR ALL OFF     ' turn off all PowerBASIC error checking
$OPTIMIZE SIZE     ' optimize for smaller code
$COMPILE UNIT      ' compile to a UNIT (.PBU)
'$COMPILE EXE       ' compile to a UNIT (.PBU)

DEFINT A-Z         ' Required for all numeric functions, forces PB to not
                   ' include floating point in UNIT (makes it smaller)
'/*------------------------------------------------------------------*/
$CODE SEG "MLIB1"
'/*-------------------------------------------------------------------*/
    FUNCTION LASTPOS(BYVAL NEEDLE AS STRING, BYVAL HAYSTACK AS STRING, BYVAL START AS INTEGER) PUBLIC AS INTEGER
      LNEEDLE = LEN(NEEDLE)
      LHAYSTACK = LEN(HAYSTACK)
      IF LNEEDLE = 0 OR LHAYSTACK = 0 THEN
        FUNCTION = 0
        GOTO EXITFUNCTION
      END IF
      IF START = 0 THEN
        START = LHAYSTACK
        S = LHAYSTACK - LNEEDLE + 1
      ELSE
        S = START
      END IF
      DO
        XRET = 0
        XT$ = MID$(HAYSTACK,S,LNEEDLE)
        IF XT$ = NEEDLE THEN XRET = S
        S = S - 1
      LOOP UNTIL XRET <> 0 OR S = 0
      FUNCTION = XRET
      EXITFUNCTION:
    END FUNCTION
'/*-------------------------------------------------------------------*/
'    CLS
'    PRINT LASTPOS(" ","abc def ghi",0);"         8                "
'    PRINT LASTPOS(" ","abcdefghi",0);"         0                "
'    PRINT LASTPOS(" ","abc def ghi",7);"       4                "
'    PRINT LASTPOS("lt","deltaepsilon",0);"     3                "
'    PRINT LASTPOS("\","C:\TESTING\TEST\",0)"    16              "
'    INPUT Z