Try this: script -q -c ‘module help null’ /dev/null > aaa.txt This works in a shell script (non-interactively) using $ script –version script (util-linux-ng 2.16) You may also be able to use expect. Also see: Catching a direct redirect to /dev/tty.
Advanced Programming in the Unix Environment, 2nd Edition has a superb chapter on the pseudo-terminal layer available in Linux. The best part is the source code which contains a pty driver and very clearly demonstrates how to use the pty interfaces. (The pty program it builds is useful in its own right if you want … Read more
Streams are blocking by default. TCP/IP streams, filesystem streams, pipe streams, they are all blocking. When you tell a stream to give you a chunk of bytes it will stop and wait till it has the given amout of bytes or till something else happens (an interrupt, an end of stream, an error). The operating … Read more
unbuffer, part of expect (sudo apt-get install expect-dev on Ubuntu Lucid), can fool a program into thinking it’s connected to a TTY. $ tty /dev/pts/3 $ echo | tty not a tty $ echo | unbuffer tty /dev/pts/11
I spent some time on this and succeeded. I found this blog during research, and decided to return and provide my solution to save the next guy some time. I’m responding as a guest with a false email so I won’t be interacting, but no further information should be required. On Jul 18 ’12 at … Read more
If stdout of apt-get is redirected to a pipe e.g., $ apt-get download firefox | cat then it doesn’t report progress (the last line e.g., 2% [1 firefox 646 kB/34.9 MB 2%] will not be in the output). stdout=subprocess.PIPE naturally creates a pipe; therefore apt-get doesn’t print the download progress in your case. If you … Read more
The stdout and stderr of the program being run can be logged separately. You can’t use pexpect because both stdout and stderr go to the same pty and there is no way to separate them after that. The stdout and stderr of the program being run can be viewed in near-real time, such that if … Read more
The -t option goes to how Unix/Linux handles terminal access. In the past, a terminal was a hardline connection, later a modem based connection. These had physical device drivers (they were real pieces of equipment). Once generalized networks came into use, a pseudo-terminal driver was developed. This is because it creates a separation between understanding … Read more