BBC BASIC for Windows
Programming >> Database and Files >> Extracting a file list type (modification)
http://bb4w.conforums.com/index.cgi?board=database&action=display&num=1512532402
Extracting a file list type (modification)
Post by michael on Dec 6th, 2017, 02:53am

I had wanted to have a program to extract all the type of files I wanted my program to know so I could make a scrolling window for non windows type applications.

So I did some modifications to this program I found in help documents and added a routine to show the stored files.

So this program will get only the ".bbc" extension programs, and store them in the

my_files()

array.

Code:
   
   DIM my_file$(500):REM holds current files.Make this as big as you think you will need
      c%=0
      PROClistdirectory(".bbc")
      REPEAT
        PRINT my_file$(c%)
        c%+=1
      UNTIL my_file$(c%)=""
      WAIT 1000
      END
      DEF PROClistdirectory(ext$)
      LOCAL dir%, sh%, res%,cou%
      DIM dir% LOCAL 317
      SYS "FindFirstFile", "*", dir% TO sh%
      IF sh% <> -1 THEN
        REPEAT
          f$= $$(dir%+44)
          IF RIGHT$(f$,4)= ext$ THEN my_file$(cou%)=f$:cou%+=1
          REM PRINT RIGHT$(f$,4):REM enable this to see the files it hides
          SYS "FindNextFile", sh%, dir% TO res%
        UNTIL res% = 0
        SYS "FindClose", sh%
      ENDIF
      ENDPROC
Re: Extracting a file list type (modification)
Post by DDRM on Dec 7th, 2017, 08:44am

Hi Michael,

Thanks- that's some useful code.

Here is an amended version, to address a few points, some of which relate to the fact that you have made a procedure, but it relies internally on global names (such as the name of the array), and also sets a variable (f$) which isn't declared as local, so could mess up the main program.

I thought it would be nice to have the routine report the number of files it had found, so I've changed it to a function. That simplifies the process of listing (or indeed processing) the resulting array data.

I've also passed the array to put the data in as a parameter, so that the procedure doesn't need to know what the host program thinks it is called, making it more flexible and re-usable. I've given it a different name so that that is obvious. It's OK to use the same name, but potentially confusing...

You can amend the searchstring in FindFirstFile (and implicitly in FindNextFile), which saves having to check separately for your extension, so I've implemented that, which allows me to simplify the function somewhat.

Note that the routine will only work in the currently selected directory: if you wanted to look elsewhere the programme would need to set that directory first (but that's what FindFirstFile does, so it's no criticism of your routine!).

Also note that "ext%" will cause problems for people using lower case keywords.

Best wishes,

D
Code:
      DIM my_files$(500):REM holds current files.Make this as big as you think you will need
      numfiles%=FNlistdirectory(".bbc",my_files$())
      FOR x%=0 TO numfiles%-1
        PRINT my_files$(x%)
      NEXT x%
      END
      DEF FNlistdirectory(ext$,store$())
      LOCAL filedata%, searchhandle%, res%,c%
      DIM filedata% LOCAL 317
      SYS "FindFirstFile", "*"+ext$, filedata% TO searchhandle%
      IF searchhandle% <> -1 THEN
        REPEAT
          store$(c%)=$$(filedata%+44)
          c%+=1
          SYS "FindNextFile", searchhandle%, filedata% TO res%
        UNTIL res% = 0
        SYS "FindClose", searchhandle%
      ENDIF
      =c%
Re: Extracting a file list type (modification)
Post by michael on Dec 7th, 2017, 1:47pm

Thanks for that.

I think I will need to make a scrolling bar that displays perhaps 20 at a time and the ability to select the file you want to work with or save over.

That shouldn't be hard to do.