Command line tips & tricks

Want to answer 'n' to lots of repetitive questions? Use the YES command
e.g.
"yes n | gzip -d *"

cat a file backwards... use tac command

One thing that (irrationally) bugs me is seeing "grep -v grep"; e.g.

ps -ef | grep java | grep -v grep

So I use this character class trick that someone showed me years ago:

ps -ef | grep [j]ava

It'll also work anywhere else that regex can be used, like awk:

ps -ef | awk '/[j]ava/ {print $2}'

Yes, pgrep will do this, but I work a lot on AIX, which doesn't have pgrep.

Also, for parallel execution, you can use xargs and nproc if parallel is not installed/available.

ls -1 *.flac | xargs -P $(nproc) -n1 -I{} oggenc "{}"

Using nproc will match the number of logical CPUs in your machine, but you could use more or less if you want.

if you have the xfce terminal installed type

xfce4-terminal --drop-down

and it will drop down from the top of your screen. if you create a launcher with that command and stick it into usr/share/applications you can run it from the menu or else assign a keyboard shortcut like F12 to activate it.
i like to run cmus music player inside this terminal because i can hide it out of the way when not needed