Programming :: PyGTK: Send Output From A File Descriptor To A Textview?

Within PyGTK I'm using gobject.spawn_async to launch a bash script. I would like the output of that bash script to be displayed within my application. I have a textview set up to receive the text ...

Here are the commands that launch the program:

Code:
def run_command(command):
global keep_pulsing
keep_pulsing=True
(cpid, cstdin, cstdout, cstderr) = gobject.spawn_async(command,flags=gobject.SPAWN_DO_NOT_REAP_CHILD|gobject.SPAWN_STDERR_TO_DEV_NULL,standard_code....

Here are the two callback functions. But like I say ... I have no idea how to get that data from the 'cstdout' file descriptor into a textbuffer.

Code:
### THE FOLLOWING ARE GLOBALS:
textview = wTree.get_widget('textview1')
textbuffer=textview.get_buffer()
def update_textview_callback(fd, condition):
global keep_pulsing
if keep_pulsing:
progressbar.pulse()
code....