List files in Igor special folders following aliases (links) and directories

Function ListUserProcFiles()
    GetFileFolderInfo/Q/P=Igor "User Procedures"   
    ListProcFiles(S_Path)
end
Function ListIgorProcFiles()
    GetFileFolderInfo/Q/P=Igor "Igor Procedures"   
    ListProcFiles(S_Path)
end

static Function ListProcFiles(PathStr)
    string PathStr
    string OldDf=GetDataFolder(1)
    //create location for the results waves...
    NewDataFolder/O/S root:Packages
    NewDataFolder/O/S root:Packages:UseProcedureFiles
    //if this is top call to the routine we need to wipe out the waves so we remove old junk
    string CurFncName=GetRTStackInfo(1)
    string CallingFncName=GetRTStackInfo(2)
    variable runningTopLevel=0
    if(!stringmatch(CurFncName,CallingFncName))
        KillWaves/Z FileNames, PathToFiles, FIleVersions
        runningTopLevel=1
        //catch if the waves were not killed sice they were in use...
        Wave/Z/T FileNames
        if(WaveExists(FileNames))
            setDataFolder OldDf
            Abort "Output waves could not be killed, they are probably part of table. Please, close all output waves tables or graphs."
        endif
    endif
    //if this was first call, now the waves are gone.
    //and now we need to create the output waves
    Wave/Z/T FileNames
    Wave/Z/T PathToFiles
    Wave/Z FIleVersions
    If(!WaveExists(FileNames) || !WaveExists(PathToFiles))
        Make/O/T/N=0 FileNames, PathToFIles
        Make/O/N=0 FileVersions
        Wave/T FileNames
        Wave/T PathToFiles
        Wave FileVersions
        //I am not sure if we really need all of those declarations, but, well, it should not hurt...
    endif
    //this is temporary path to the place we are looking into now...  
    NewPath/Q/O tempPath, PathStr
    //list al items in this path
    string ItemsInTheFolder= IndexedFile(tempPath,-1,"????")+IndexedDir(tempPath, -1, 0 )
    //remove all . files.
    ItemsInTheFolder = GrepList(ItemsInTheFolder, "^\." ,1)
    //Now we removed all junk files on Macs (starting with .)
    //now lets check what each of these files are and add to the right lists or follow...
    variable i, imax=ItemsInList(ItemsInTheFolder)
    string tempFileName, tempScraptext
    For(i=0;i<imax;i+=1)
        tempFileName = stringfromlist(i,ItemsInTheFolder)
        GetFileFolderInfo/Q/P=tempPath tempFileName
        if(V_isAliasShortcut)
            //is alias, need to follow and look further. Use recursion...
            ListProcFiles(S_aliasPath)
            //and now when we got back, fix the path definition to previous or all will crash...
            NewPath/Q/O tempPath, PathStr
        elseif(V_isFolder) 
            //is folder, need to follow into it. Use recursion.
            ListProcFiles(PathStr+tempFileName+":")
            //and fix the path back or all will fail...
            NewPath/Q/O tempPath, PathStr
        elseif(V_isFile)
            //this is real file. Store information as needed.
            Redimension/N=(numpnts(FileNames)+1) FileNames, PathToFiles,FileVersions
            FileNames[numpnts(FileNames)] = tempFileName
            PathToFiles[numpnts(FileNames)] = PathStr
            //try to get version from #pragma version = ... This seems to be the most robust way I found...
            if(stringmatch(tempFileName, "*.ipf"))
                Grep/P=tempPath/E="(?i)^#pragma[ ]*version[ ]*=[ ]*" tempFileName as "Clipboard"
                tempScraptext = GetScrapText()
                if(strlen(tempScraptext)>10)        //found line with #pragma version"
                    tempScraptext = replaceString("#pragma",tempScraptext,"")   //remove #pragma
                    tempScraptext = replaceString("version",tempScraptext,"")       //remove version
                    tempScraptext = replaceString("=",tempScraptext,"")         //remove =
                    tempScraptext = replaceString("\t",tempScraptext,"  ")          //remove optional tabulators, some actually use them.
                    //forget about the comments behind the text.
                                       //str2num is actually quite clever in this and converts start of the string which makes sense.
                    FileVersions[numpnts(FileNames)]=str2num(tempScraptext)
                else             //no version found, set to NaN
                    FileVersions[numpnts(FileNames)]=NaN
                endif
            else                    //no version for non-ipf files
                FileVersions[numpnts(FileNames)]=NaN
            endif
        endif
    endfor
    if(runningTopLevel)
        //some output here...
        print "Found   "+num2str(numpnts(FileNames))+"  files in   "+PathStr+" folder, its subfolders and linked folders and subfolders"
        KillPath/Z tempPath
    endif
   
    setDataFolder OldDf
end