I am writing a Python code which calls a command line (e.g. python itself) and the command will open its own shell. How can Python take control of this shell?
import subprocess
subprocess.call(['./testprg'])
# testprg will open its own shell
# so the code below will not work
subprocess.call(['i 2'])
testprg is another program which open a shell prompt. Enter "i 2" will trigger a "insert" command with the value 2.
It can't. subprocess does not interact with interactive shells.
You need to use stdin=PIPE in the first subprocess an write 'i 2\n' to that pipe.
Consider using pexpect though if you want to interact with interactive programs. It might make your life much easier.
Have a look at subprocess.Popen.communicate(). If it's just about receiving some lines and sending commands to the other process, it should be what you're looking for.
Some example:
pout, perr = Popen([tools['PASSWD'], username], stdin=PIPE, stdout=PIPE,
stderr=PIPE).communicate("%s\n%s\n" % (password, password))
./cmd and type in i 2, and return, as if you would type in from keyboard. So then you get the error? You're running linux and it tells you something about win32?