False = 0: True = NOT False ' you need these defined!

ReadConfigFile() ' as it would appear in your main code
END

'
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' ''''
' Subroutine
' This subroutine reads the user preferences from the configuration
' file. If the file does not exist, it is created.
'
' We need two different ways of testing for the file's existance
' because MMBasic only returns valid Error Numbers for files on the
' A: or B: drives. It does not return a useful error number if
' the file does not exist in DOS.
'
' The Config file is the name of the calling program -.BAS +.CFG
'
'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''' ''''
'
Sub ReadConfigFile()

Local ConfFile$, In$

' As at the version this was written for, V4.3, the user has to specify
' the name of the program when it is run - ie RUN CONFIG or RUN CONFIG.BAS
' If no program name is specified, MM.FNAME$ returns an empty string.

if MM.FNAME$ = "" then
? "You must provide the program name when you type RUN - eg RUN CONFIG"
? "Otherwise this program will not be able to work out the name of "
? "of the associated .cfg file."
END
ENDIF

' Open the Config file if it exists. If it doesn't exist, create it.
ConfFile$ = LEFT$(MM.FNAME$, LEN(MM.FNAME$) - 4) + ".cfg" ' replace .bas with .cfg
if FileExists(ConfFile$) then

' Read in the values - allocate to global variables
? "File ";ConfFile$; " exists"
Open ConfFile$ for input as #8


Close #8
else

? "File ";ConfFile$; " does NOT exist"
Open ConfFile$ for output as #8
' Prompt for the values and create the config file. Allocate to global variables.


Close #8
endif


End Sub ' ReadConfigFile

'
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
' Function
' Check whether a file exists.
' Returns a Boolean True or False.
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
' Uses two different methods to check for a file's existence,
' depending on whether the code is run under DOS, or on a
' Maximite.
' I've submitted a bug report about MM.DEVICE$ returning ""
' under DOS MMBasic 4.3, and I've used a workaround that
' assumes that "" is only returned if running under DOS.
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
'
Function fileExists(FileName$)

Local Answer$, bFileExists

if (MM.DEVICE$ = "DOS") OR (MM.DEVICE$ = "") then ' workaround for bug - see comment above.
open "exist.bat" for output as #8
Print #8, "if exist " + chr$(34) + FileName$ + chr$(34) + " ( "
Print #8, " echo YES> exist.tmp"
Print #8, ") Else ("
Print #8, " echo NO> exist.tmp"
Print #8, ")"
Print #8, "Exit"
Close #8

' Run batch that redirects DIR results to exist.tmp file.
' Redirect all messages from the batch file to nul (ie, not displayed)
SYSTEM "exist.bat > nul"

' Read the single line from exist.tmp for the answer as to whether the file exists.
Open "exist.tmp" for input as #8
Line Input #8, Answer$
bFileExists = (Answer$ <> "YES")
Close #8
KILL "exist.bat" ' and clean up
KILL "exist.tmp"
else ' running on a Maximite or similar hardware
' Turn off Abort on Error so we can capture the Error Number
Option Error Continue
Open FileName$ for Input as #8

If MM.ERRNO = 6 then ' can't find file
bFileExists = False
elseif MM.ERRNO = 0 then
bFileExists = True
CLOSE #8
else
? "ERROR: the Existence Check for file "; ConfFile$; " returned MM.ERRNO "; MM.ERRNO
? "The description of MM.ERRNO"; MM.ERRNO; " is: "; ErrNoDesc$(MM.ERRNO)
' Close #8
Option Error Abort
END
Endif
Option Error Abort
Endif

fileExists = bFileExists

End Function ' fileExists

'
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
' Function
' Return the matching Description for an MMBasic
' Error Number.
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
' The descriptions were taken from the V4.3 manual.
''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
'
Function ErrNoDesc$(ErrNo)

Local Desc$

if ErrNo = 0 then
Desc$ = "No error"
elseif ErrNo = 1 then
Desc$ = "No SD card found"
elseif ErrNo = 2 then
Desc$ = "SD card is write protected"
elseif ErrNo = 3 then
Desc$ = "Not enough space"
elseif ErrNo = 4 then
Desc$ = "All root directory entries are taken"
elseif ErrNo = 5 then
Desc$ = "Invalid filename"
elseif ErrNo = 6 then
Desc$ = "Cannot find file"
elseif ErrNo = 7 then
Desc$ = "Cannot find directory"
elseif ErrNo = 8 then
Desc$ = "File is read only"
elseif ErrNo = 9 then
Desc$ = "Cannot open file"
elseif ErrNo = 10 then
Desc$ = "Error reading from file"
elseif ErrNo = 11 then
Desc$ = "Error writing to file"
elseif ErrNo = 12 then
Desc$ = "Not a file"
elseif ErrNo = 13 then
Desc$ = "Not a directory"
elseif ErrNo = 14 then
Desc$ = "Directory not empty"
elseif ErrNo = 15 then
Desc$ = "Hardware error accessing the storage media"
elseif ErrNo = 16 then
Desc$ = "Flash memory write failure"
else
Desc$ = "******** " + ErrNo + " is an invalid Error Number iaw V4.3 manual **********"
endif

ErrNoDesc$ = Desc$

End Function ' ErrNoDesc$