'**************************************************
' *******  Merge for CMM2, combines 2 files *******
'*****************  V 0.01  ***********************
'**************************************************

Const TRUE  =1
Const FALSE =0

Dim F1$,F2$,TF$,YN$,FSize As integer

'Input "file1" F1$
'Input "file2" F2$
'Input "Target file" TF$

F1$="M.txt"
F2$="S.txt"
TF$="New.txt"

'Print FileExists(F1$)
'Print FileExists(F2$)
'Print FileExists(TF$)

Print "Merge for CMM2"
Print
Print "Files to merge: " F1$ " + " F2$
Print "Target file   : " TF$

If Not FileExists(F1$) Then Print F1$ " doesn't exist!":End
If Not FileExists(F2$) Then Print F2$ " doesn't exist!":End
If FileExists(TF$) Then
  Print "Target file: " TF$ " exist! Overwrite? ";
  Input "(Y/N)";YN$
  If YN$<>"Y" And YN$<>"y" Then
    Print :Print "Program terminated!"
    End
  EndIf
EndIf

FSize=Merge(F1$, F2$, TF$)

Print :Print TF$ " created, file size = " FSize

End

Function Merge(FN1$, FN2$, TFN$) As integer
   Open FN1$ For input As #1
   Open TFN$ For output As #3

   Do While Not Eof(#1)
     Print #3, Input$(1,#1);
     Merge=Merge+1
   Loop

   Close #1

   Open FN2$ For input As #2

   Do While Not Eof(#2)
     Print #3, Input$(1,#2);
     Merge=Merge+1
   Loop

   Close #2,#3
End Function


Function FileExists(FileName$) 'NEW untested
 FileExists=not(MM.INFO(FILESIZE file$)=-1)
End Function


'Function FileExists(FileName$)
'  On error skip
'  Open FileName$ For input As #10
' If MM.Errno=0 Then
'   FileExists=TRUE
'   Close #10
' Else
'   FileExists=FALSE
' EndIf
' On error abort
'End Function

mkdir "test"
> cd "test"
> chdir "test"
> copy "a:/temp.bas" to "new.bas"
> files
17:15 30-07-2020       2129  new.bas

Function FileExists(FileName$) 'NEW untested
  FileExists=not(MM.INFO(FILESIZE file$)=-1)
End Function

Function FileExists(FileName$) 'NEW untested
  FileExists=not(MM.INFO(FILESIZE FileName$)=-1)
End Function