Open a zip file with my program

Hi there.

I just need a starting point for a progam I am writing. I need to access a zipped file, and not sure what to do next.

Do I take the file and open it into a special folder, or can I read within a zipped file.


How should we know what your app is supposed to do with the zip file? You could - like - unzip the zip file.

You can unzip it with unzip in Shell class.

Or use a plugin from Einhugur’s e-CryptIt Engine for Xojo or my MBS Xojo Compression Plugin with the archive classes to do it within the app.

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I don’t know if you are aware of what .cbz or .cbr’s are (comic book files) but I want to be able to open the file to view the .jpg’s inside. That is all cbr’s and cbz’s are.

So I was thinking one way might be to open the file, put it in an application folder and delete it when they close the file.


Looks like you need to “unzip” multiple files: Comic-Book-Format – Wikipedia .

Not sure what’s the capabilities of the upcoming feature:

But inspecting contents without completely unpacking them would be a great addition

You could look into this:

Unless the tool you use has an unzip to memory, you probably need to unzip to a temp file then read the image.
ZipFolders on Windows used to be great- if a folder was named, it showed up as a folder in most situations, and unzipped on demand.
(Current Windows doesnt seem to do it quite the same way any more… maybe I broke something…)

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Unknown. And you can’t use what may not be available today.
If you need plug-in free, please use unzip via shell class.

How dumb I am, I thought everybody knew what’s upcoming and only I was saying “Not sure what’s the capabilities of the upcoming feature”; also I thought that we could open a hole in the time-space tissue and use it now from the future. Thank you for informing me that I can’t.

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The best option by far, without any 3rd party plugins :

My app has similar features, receives and send / expands and compresses ZIP / GZ / TAR and other formats. Use that library above to Inflate / deflate.


Thank you ever so much for this Sveinn. However I have never used GitHub… (sorry never had to).

Can you explain how get get this and use it?

I’m not sure which files I have to get and how to get them sort of thing.


Read Andrew’s manual, specially this part: How to incorporate zlib into your Realbasic/Xojo project


You can download it here also

Thanks ever so much. I have printed off the docs here so I can read them in peace (I’m old technology and need paper!)

Once again, thank you very much!

Hi Sveinn.

I found another way to do what I want, using shell commands, however I must be doing something wrong, because i never change to the directory I want.

Here is my code:

var s as new shell
var cmd as string

s.Execute ("dir")

window1.TextArea1.text = s.Result

s.Execute ("cd..")

Window1.TextArea1.text = s.Result

s.Execute ("dir")

Window1.TextArea1.text = s.Result

I always stay in the same directory. I never even move up one directory level. Can you see what I am doing wrong?


Here’s some Xojo code using Windows explorer to unzip a file. Note this is using the older AP1, but should be easy to convert to API2.

Public Sub UnzipWin32(zipfile as FolderItem, ExtractTo as FolderItem)
  #if TargetWin32
    Dim fso, objShell, FilesInZip, MyFolder1, MyFolder2 As OLEObject
    Dim ZipParams(1), ExtractParams(1) As variant
    ZipParams(1) = ZipFile.ShellPath
    ExtractParams(1) = ExtractTo.ShellPath
    // If the extraction location does not exist create it
    fso = New OLEObject("Scripting.FileSystemObject")
    If NOT fso.FolderExists(ExtractTo.ShellPath) Then
    End If
    objShell = New OLEObject("Shell.Application")
    MyFolder1 = objShell.Invoke("NameSpace", ZipParams)
    MyFolder2 = objShell.Invoke("NameSpace", ExtractParams)
    //Extract the contants of the zip file.
    fso = Nil
    objShell = Nil
    exception err as OLEException
      msgbox err.message
End Sub

Shell executions are self contained. Once they finish the environment reverts to the original. The exception would be if you’re running in Interactive mode. Then the first command is s.Execute and subsequent commands are issued via Write/Writeline.

CBR are RAR compressed files, unziping will not work, you need an external tool. The easiest way is to use 7z (it is opensource) to uncompress, the advantage is that 7z automatically recognizes the file format and the same code will work for both CBZ and CBR.

To whom it may inspire,
this is my way to renew / update a zipped Database by Downloading in normal User-Account with MAC, WIN or Linux.

This method involves the local installation of updated documents in various formats and a fairly large database, which is transferred in zipped form (supplied by the server as First, it is checked here whether the user is still using the old version and, if so, the task is terminated.

The file then transferred is successfully unpacked and installed with the on-board resources of the shell (WIN "tar -xvf "…, MAC/LINUX "unzip "…), which has worked without any problems so far.

Warm greetings from Rhineland-Palatinate
Bernd Sebastian

Var url As String = app.sockDom+""+app.VerzeichnisOrdner+"/"+DB+"/"+Dok
Var downloadFile As FolderItem 
Var cf As Integer
Var timeout As Integer = 60 'sec
#If TargetMacOS
  downloadFile = SpecialFolder.ApplicationData.Child("DRG-Recherche Prefs").child(DB).Child(Dok)
  downloadFile = SpecialFolder.Preferences.Child("DRG-Recherche Prefs").child(DB).Child(Dok)
Downloader.Yield = true ' synchronously
Anzeige.Value = "File-Transfer gestartet ..."

if Downloader.Get(url, downloadFile, timeout) then ' timeout s.o.
  if downloadFile <> Nil and downloadFile.Exists then
    loadcount = loadcount+1
    newcount = newcount-1
    Aktion.Text = Aktion.Text+"Server-Datei """+Dok+""" wurde geladen."+chr(13)
    if DB="Individuelle" or DB="Komplexe" or DB="Scores" then DateiChanged = true
    Anzeige.Value = "File-Transfer abgebrochen"
    Aktion.Text = Aktion.Text+"Server-Datei """+Dok+""" ist nicht vorhanden."+chr(13)
  end if
  if newcount > 1 then DownloadAll.Visible = true else DownloadAll.Visible = false
  if loadcount > 1 then ButtonNeu.Visible = true else ButtonNeu.Visible = false
  if loadcount > 0 then ButtonOrdner.Visible = true
  if DateiChanged then FertigButton.Backdrop = Pfeil_back
  If DB = "HMV" then ' HMV entpacken
    ' Falls HMV App läuft, diese beenden, da bei aktiver Datenbank Neuinstallation nicht möglich
    Var m As New Mutex("MutexHV")
    If Not m.TryEnter Then
      Var sh As New Shell
      sh.mode = 0 ' One-shot
      #If TargetWindows
        sh.Execute("taskkill /IM HMV.EXE /F")
      #Else ' MAC / LINUX
        sh.Execute("ps -ax | grep HMV")
        Var pid As String = sh.Result.ToInteger.ToString
        sh.Execute("Kill "+pid)
      Aktion.Text = Aktion.Text+"HMV-Tool und Datenbank-Registrierung wurde beendet!"+chr(13)
    End If
    Aktion.Text = Aktion.Text+"HMV-Datenbank wird entpackt und installiert ..."+chr(13)
      Var sh As New Shell
      sh.TimeOut = 10000 ' 10s
      if downloadFile <> Nil and downloadFile.Exists and not downloadFile.IsFolder then
        #If TargetWindows
          sh.Execute("tar -xvf "+downloadFile.ShellPath+" -C "+downloadFile.Parent.ShellPath)
          if sh.ErrorCode <> 0 then Aktion.Text = Aktion.Text+"err: "+sh.ErrorCode.ToString+" res:"+sh.Result+"path: "+downloadFile.ShellPath+chr(13)
        #Else ' Mac & Linux
          ' hier zuerst die alte DB lokal löschen
          downloadFile = downloadFile.Parent.Child("HMV.xml")
          if downloadFile <> Nil and downloadFile.Exists then downloadFile.Remove ' ###
          sh.Execute("unzip "+downloadFile.ShellPath+" -d "+downloadFile.Parent.ShellPath) 
          ' alternativ mit Folderanzeige (auch in WIN/Linux): downloadFile.Open
        downloadFile = downloadFile.Parent.Child("HMV.xml")
        if downloadFile <> Nil and downloadFile.Exists then ' and not downloadFile.IsFolder then
          Aktion.Text = Aktion.Text+"Test: Datenbank entpackt und angelegt."+chr(13)
          Aktion.Text = Aktion.Text+"Test: Datenbank nicht angelegt!"+chr(13)
        end if
        Aktion.Text = Aktion.Text+"Installation beendet."+chr(13)
        Aktion.Text = Aktion.Text+"Entpacken gescheitert!"+chr(13)
        Aktion.Text = Aktion.Text+"Bitte neu laden oder Ordner aufrufen und doppelklicken."+chr(13)
      end if
      Aktion.Text = Aktion.Text+"Installation fehlgeschlagen!"+chr(13)
    End try
  end if
  Anzeige.Value = "Weitere Datei transferieren oder Abschließen mit Zurück-Pfeil"
    cf = Downloader.ErrorCode
    Anzeige.TextColor = &cFF000000
    Warnung.Visible = true
    Anzeige.Value = "Überlastung! Bitte warten und erneut starten."
    Aktion.Text = Aktion.Text+"Server-Datei """+Dok+""" z. Zt. nicht ladbar! Error: "+str(cf)
    if cf = -1 then Aktion.Text = Aktion.Text+" timeout "+str(timeout)+" sec"
    Aktion.Text = Aktion.Text+chr(13)
    Aktion.Text = Aktion.Text+"Evtl. abgebrochene Datei bitte löschen und später neu laden!"+chr(13)
  End try
end if

Hi Mar Tin.

It matters not to me (generally) which decompression program I use. I will happily use 7z.

My issue is that if I wish to decompress it, in my manner of doing things, I want to run a command from from my program to decompress to a temporary folder, so I can read the pages in.

What is making me crazy is using the shell command. It seems no matter how hard I try, I can only run one command. Even when I start different shells, I never move through directories to get to where I want to be.

var s as new shell
var s2 as new shell
var s3 as new shell

var cmd as string

s.Execute ("dir")

window1.TextArea1.text = s.Result

s2.Execute ("cd..")
window1.TextArea1.text = "======================"
Window1.TextArea1.text = s.Result

s3.Execute ("dir")
window1.TextArea1.text = "**********************************"
Window1.TextArea1.text = s.Result

Return True