wxPython: how to create a bash shell window?

Question

I want to create a popup window using wxPython that acts like a bash shell. I don't want a terminal emulator, I don't need job control, I just want a REPL (Read, Eval, Print Loop) based on a bash process.

Is there an easy way to do that with wxPython? I know the basic concept from my days as a tcl/tk programmer but my wxPython fu is weak and I don't want to have to reinvent the wheel if I don't have to. I've read a little about py.shell. Shell but that looks like it creates a python shell and I want one to run bash commands instead.

Answer 1

Hi, i searched but there doesn't seem to be any exiting bash shell for wxPython though wx.py module has Shell module which is for python interpretor good thing is you can pass your own interpretor to it,so I have come with very simple bash interpreter. example currently reads only one line from bash stdout, otherwise it will get stuck, in real code you must read output in thread or use select

import wx
import wx.py
from subprocess import Popen, PIPE

class MyInterpretor(object):
    def __init__(self, locals, rawin, stdin, stdout, stderr):
        self.introText = "Welcome to stackoverflow bash shell"
        self.locals = locals
        self.revision = 1.0
        self.rawin = rawin
        self.stdin = stdin
        self.stdout = stdout
        self.stderr = stderr

        #
        self.more = False

        # bash process
        self.bp = Popen('bash', shell=False, stdout=PIPE, stdin=PIPE, stderr=PIPE)


    def getAutoCompleteKeys(self):
        return [ord('\t')]

    def getAutoCompleteList(self, *args, **kwargs):
        return []

    def getCallTip(self, command):
        return ""

    def push(self, command):
        command = command.strip()
        if not command: return

        self.bp.stdin.write(command+"\n")
        self.stdout.write(self.bp.stdout.readline())

app = wx.PySimpleApp()
frame = wx.py.shell.ShellFrame(InterpClass=MyInterpretor)
frame.Show()
app.SetTopWindow(frame)
app.MainLoop()

Answer 2

Going to see what i can come up with.

But if you change your mind and decide to use pygtk instead, here it is:

enjoy!!

EDIT

I started making a poor man's version of a terminal using the text control widget. I stopped because there are flaws that can't be fixed, such as when you use the sudo command.

import wx
import subprocess

class MyFrame(wx.Frame):
    def __init__(self, *args, **kwds):
     # begin wxGlade: MyFrame.__init__
     kwds["style"] = wx.DEFAULT_FRAME_STYLE
     wx.Frame.__init__(self, *args, **kwds)

     self.prompt = "user@stackOvervlow:~ "
     self.textctrl = wx.TextCtrl(self, -1, '', style=wx.TE_PROCESS_ENTER|wx.TE_MULTILINE)
     self.default_txt = self.textctrl.GetDefaultStyle()
     self.textctrl.AppendText(self.prompt)

     self.__set_properties()
     self.__do_layout()
     self.__bind_events()


    def __bind_events(self):
     self.Bind(wx.EVT_TEXT_ENTER, self.__enter)


    def __enter(self, e):
     self.value = (self.textctrl.GetValue())
     self.eval_last_line()
     e.Skip()


    def __set_properties(self):
     self.SetTitle("Poor Man's Terminal")
     self.SetSize((800, 600))
     self.textctrl.SetFocus()

    def __do_layout(self):
     sizer_1 = wx.BoxSizer(wx.VERTICAL)
     sizer_1.Add(self.textctrl, 1, wx.EXPAND, 0)
     self.SetSizer(sizer_1)
     self.Layout()

    def eval_last_line(self):
     nl = self.textctrl.GetNumberOfLines()
     ln =  self.textctrl.GetLineText(nl-1)
     ln = ln[len(self.prompt):]
     args = ln.split(" ")

     proc = subprocess.Popen(args, stdout=subprocess.PIPE)
     retvalue = proc.communicate()[0]

     c = wx.Colour(239, 177, 177)
     tc = wx.TextAttr(c)
     self.textctrl.SetDefaultStyle(tc)
     self.textctrl.AppendText(retvalue)
     self.textctrl.SetDefaultStyle(self.default_txt)
     self.textctrl.AppendText(self.prompt)
     self.textctrl.SetInsertionPoint(GetLastPosition() - 1)

if __name__ == "__main__":
    app = wx.PySimpleApp(0)
    wx.InitAllImageHandlers()
    frame_1 = MyFrame(None, -1, "")
    app.SetTopWindow(frame_1)
    frame_1.Show()
    app.MainLoop()

If really wanted, this could be worked upon.

Answer 3

ok here is another try, which reads all output and errors too, in a separate thread and communicates via Queue. I know it is not perfect(e.g. command with delayed output will not work and there output will get into next commnd for example tryr sleep 1; date) and replicating whole bash not trivial but for few commands i tested it seems to work fine

Regarding API of wx.py.shell I just implemented those method which Shell class was calling for Interpreter, if you go thru source code of Shell you will understand. basically

• push is where user entered command is sent to interpreter
• getAutoCompleteKeys returns keys which user can user for auto completing commands e.g. tab key

• getAutoCompleteList return list of command matching given text

• getCallTip "Display argument spec and docstring in a popup window. so for bash we may show man page :)

here is the source code

import threading
import Queue
import time

import wx
import wx.py
from subprocess import Popen, PIPE

class BashProcessThread(threading.Thread):
    def __init__(self, readlineFunc):
        threading.Thread.__init__(self)

        self.readlineFunc = readlineFunc
        self.outputQueue = Queue.Queue()
        self.setDaemon(True)

    def run(self):
        while True:
            line = self.readlineFunc()
            self.outputQueue.put(line)

    def getOutput(self):
        """ called from other thread """
        lines = []
        while True:
            try:
                line = self.outputQueue.get_nowait()
                lines.append(line)
            except Queue.Empty:
                break
        return ''.join(lines)

class MyInterpretor(object):
    def __init__(self, locals, rawin, stdin, stdout, stderr):
        self.introText = "Welcome to stackoverflow bash shell"
        self.locals = locals
        self.revision = 1.0
        self.rawin = rawin
        self.stdin = stdin
        self.stdout = stdout
        self.stderr = stderr

        self.more = False

        # bash process
        self.bp = Popen('bash', shell=False, stdout=PIPE, stdin=PIPE, stderr=PIPE)

        # start output grab thread
        self.outputThread = BashProcessThread(self.bp.stdout.readline)
        self.outputThread.start()

        # start err grab thread
        self.errorThread = BashProcessThread(self.bp.stderr.readline)
        self.errorThread.start()

    def getAutoCompleteKeys(self):
        return [ord('\t')]

    def getAutoCompleteList(self, *args, **kwargs):
        return []

    def getCallTip(self, command):
        return ""

    def push(self, command):
        command = command.strip()
        if not command: return

        self.bp.stdin.write(command+"\n")
        # wait a bit
        time.sleep(.1)

        # print output
        self.stdout.write(self.outputThread.getOutput())

        # print error
        self.stderr.write(self.errorThread.getOutput())

app = wx.PySimpleApp()
frame = wx.py.shell.ShellFrame(InterpClass=MyInterpretor)
frame.Show()
app.SetTopWindow(frame)
app.MainLoop()

Answer 4

I found the solution for my problem. Funny how it never turned up in google searches before now. It's not production ready code, but it ultimately what I was looking for -- a way to run a bash shell in a wxPython window.

http://sivachandran.blogspot.com/2008/04/termemulator-10-released.html