On Mar 14, 3:03 am, Roman Medina-Heigl Hernandez <ro...@rs-labs.com> wrote: > Karthik Gurusamy escribió: > > > > > On Mar 13, 6:39 pm, Roman Medina-Heigl Hernandez <ro...@rs-labs.com> > > wrote: > >> Hi, > > >> I'm experimenting with Python and I need a little help with this. What I'd > >> like is to launch an interactive shell, having the chance to send first > >> several commands from python. I've written the following code: > > >> ============= > > >> #!/usr/bin/env python > > >> import sys, subprocess > > >> exe = "/bin/sh" > >> params = "-i" > > > -i says shell to be interactive. So looks like it is directly trying > > to read from the terminal. > > Well, then the question will be: is there any way to tell python to > directly "map" the terminal to the subprocess?
pexpect seems to be the solution for such problems :). [other applications include ssh which asks for password from terminal (not ssh's stdin)] http://pexpect.sourceforge.net/pexpect.html > > >> proc = subprocess.Popen([exe, params], stdin=subprocess.PIPE) > > > proc = subprocess.Popen([exe,], stdin=subprocess.PIPE) > > > works for me; but if there is an error 'sh' terminates. > > > If you want to simulate interactive, explore the pexpect module. > > I'll get it a try :))) > > >> proc.stdin.write("id\n") > > >> while True: > >> line = sys.stdin.readline() > >> if not line: > > > note that a simple enter terminates the shell which you may not want. > > Test my code and you'll see that this is not true :) When you hit enter > line will contain '\n' so it's not empty. You are right. I thought readline() strips the trailing \n (It doesn't and shouldn't as it's necessary for the case a file ends without a newline). > > >> break > >> proc.stdin.write(line) > > Btw, another curiosity I have: is it possible to make a print not > automatically add \n (which is the normal case) neither " " (which happens > when you add a "," to the print sentence)? I found an alternative not > using print at all, eg: sys.stdout.write("KKKKK"). But it resulted strange > to me having to do that trick :) I am also aware of only the sys.stdout.write solution. python3.0 has a way to do it. >>> help(print) Help on built-in function print in module builtins: print(...) print(value, ..., sep=' ', end='\n', file=sys.stdout) Prints the values to a stream, or to sys.stdout by default. Optional keyword arguments: file: a file-like object (stream); defaults to the current sys.stdout. sep: string inserted between values, default a space. end: string appended after the last value, default a newline. >>> print('hello', end='') hello>>> Karthik > > Thank you for all your comments and comprenhension. > > -r > > > > >> sys.exit() > > >> ============= > > >> The problem is that when I launch it, python proggy is automatically > >> suspended. The output I got is: > > >> ro...@rslabs:~/pruebas$ ./shell.py > >> ro...@rslabs:~/pruebas$ uid=1000(roman) gid=1000(roman) groups=1000(roman) > >> ro...@rslabs:~/pruebas$ > > >> [2]+ Stopped ./shell.py > >> ro...@rslabs:~/pruebas$ > > >> Why and how to fix it? Would you suggest a better and more elegant way to > >> do what I want? > > > As I see it, 'sh' is attempting to read from the keyboard and not from > > stdin. > > > Karthik > > >> Thank you. > > >> -- > > >> Saludos, > >> -Roman > > >> PGP Fingerprint: > >> 09BB EFCD 21ED 4E79 25FB 29E1 E47F 8A7D EAD5 6742 > >> [Key ID: 0xEAD56742. Available at KeyServ] > > > -- > >http://mail.python.org/mailman/listinfo/python-list > > -- > > Saludos, > -Roman > > PGP Fingerprint: > 09BB EFCD 21ED 4E79 25FB 29E1 E47F 8A7D EAD5 6742 > [Key ID: 0xEAD56742. Available at KeyServ] -- http://mail.python.org/mailman/listinfo/python-list
