Ubuntu – the “yes” command

command line

I issued a command in the Ubuntu terminal that required me to type yes but I discovered that it only asks me the first time, but I had already pressed enter before I realized. So I expected a "command not found" message but instead I got a never-ending stream of "y"s. This seems to be the only thing this does, so I'm wondering what the point of this command is and why it outputs "y"s? (Ubuntu 11.10)

Best Answer

From wikipedia:

By itself, the yes command outputs 'y' or whatever is specified as an argument, followed by a newline repeatedly until stopped by the user or otherwise killed; when piped into a command, it will continue until the pipe breaks (i.e., the program completes its execution).

It can also be used to test how well a system handles high loads, as using yes results in 100% processor usage, for systems with a single processor (for a multiprocessor system, a process must be run for each processor). This, for example, can be useful for investigating whether a system's cooling system will be effective when the processor is running at 100%.

Related Solutions

Ubuntu – How to enter the Default Keyring password via the command line

Thanks to python-gnomekeyring, this is relatively easy:

python -c "import gnomekeyring;gnomekeyring.unlock_sync(None, 'my password');"

Or as a proper script:

#!/usr/bin/env python
import gnomekeyring
gnomekeyring.unlock_sync(None, 'my password');

I think you don't need to install the package. But it can't hurt to try.

Keep in mind that storing your password on your hard disk is an immense security risk. You should be using this instead:

#!/usr/bin/env python

import gnomekeyring
import getpass

gnomekeyring.unlock_sync(None, getpass.getpass('Password: '));

You can save this script, for example, as unlock-keyring.py and then do the following:

sudo mv unlock-keyring.py /usr/bin/unlock-keyring
sudo chmod a+x /usr/bin/unlock-keyring

From then, you can always just type unlock-keyring and be prompted for a password. Don't do this with the version that contains your password.

You can replace None with the name of your keyring, e.g. 'session', if you want to unlock one that isn't the default.

I'm having a hard time testing this properly, so please let me know if it doesn't work and I'll take a look at it right away. Also let me know if it does work :-)

Ubuntu – Launch command in gnome-terminal, then close gnome-terminal without ending executed command

Solution to your problem

The right solution here is to omit calling gnome-terminal and bash and even setting an unneeded variable in the first place, all of that is not needed in your case:

mpv -- "$(yad --entry)"

I added quotes to handle the URL correctly, this ensures it can contain e.g. whitespaces and ampersand signs (&) and the command still works. -- tells mpv to stop looking for options and treats whatever you choose to give it as an argument instead. Image the common case where you have a file named --version in the directory you start mpv from and just enter this filename, how can mpv know whether to show you its version string or open the file?

Answer to your question

nohup or disown can be used to detach a process from the shell that started it, see Differences between "<command> & disown" and "nohup <command> & disown".

In your case the correct solution would be:

gnome-terminal -e nohup mpv -- "$(yad --entry)"

However for a much better solution see above.