# bash ignores what I type while “apt-get” is running

I am encountering this problem:

I type sudo apt-get install <package>, and hit Enter. apt-get starts resolving dependencies and downloading/installing packages. While it is running, I want to enter another command in the same terminal, so I type it (let's say echo done).

The problem is, I type echo done and Enter, but when apt-get finishes, the echo done is not executed. The shell comes back to me with a prompt, and there is nothing in its input buffer. So, bash seems to ignore my input while apt-get is running. This "ignoring" doesn't seem to happen with any other command.

I would like to figure out why this is happening, and if I can change the behaviour somehow.

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I recommend reporting this as a bug. –  Eliah Kagan May 29 '12 at 4:13
FWIW, I tried it right after doing sudo apt-get update, and it worked as expected. –  Marty Fried May 29 '12 at 4:26
@MartyFried, just to be sure: once apt-get finishes, I can type commands and everything works normally. I can't type commands while apt-get is running though. I am using Ubuntu 12.04. I guess I should report this as a bug. –  user536048 May 29 '12 at 4:36
I understand. I entered the command quickly while it was still running, and when it finished several seconds later, it echoed the command and the result. But I just did the update, and didn't actually install anything. –  Marty Fried May 29 '12 at 4:47
Did you add the -y switch OR confirm installation before entering the other command? Otherwise your input just goes to the prompt which comes up when trying to install larger packages. –  izx May 29 '12 at 5:30

You might want to try to execute any command by adding in the very end of the command the &., e.g.: dolphin &. This way the process will run on the background and the terminal will be free to operate on.
Update: it seems, however, that interactive processes, like sudo apt-get install <package> that expect a user input (for example sudo's password) just wait in the background. They can be re-reached with the command fg.