ASM

DISK I/O

Test if a file exists

Try the following function:

LOCAL FN FileCheckExist(FileName$,VolRefNum%)
  DIM ParamBlock.ioHFQElSiz
  ParamBlkPtr&=VARPTR(ParamBlock)
  DEF BLOCKFILL (ParamBlkPtr&,128,0)
  DoesExist%=_False
  ParamBlock.ioVRefNum = VolRefNum%
  ParamBlock.ioNamePtr& = @FileName$
  osErr%=FN HGETFILEINFO(ParamBlkPtr&)
  LONG IF osErr%=_noErr
    ParamBlock.iocompletion% = _noErr
    DoesExist%=_True
  XELSE
    DoesExist%=_False
  END IF
END FN = DoesExist%

Call it using the following:

FileName$= "ThisIsMyFile"
VolRefNum%=prefsVol%
DoesExist%=FN FileCheckExist(FileName$,VolRefNum%)
LONG IF DoesExist%=_True
  PRINT "Yes, it exists"
XELSE
  PRINT "No, it does not exist"
END IF