Shell - How to find directory of some command?

Question

I know that when you are on shell, the only commands that can be used are the ones that can be found on some directory set on PATH. Even I don\'t know how to see what dirs a

Answer 1

PATH is an environment variable, and can be displayed with the echo command:

echo $PATH

It's a list of paths separated by the colon character ':'

The which command tells you which file gets executed when you run a command:

which lshw

sometimes what you get is a path to a symlink; if you want to trace that link to where the actual executable lives, you can use readlink and feed it the output of which:

readlink -f $(which lshw)

The -f parameter instructs readlink to keep following the symlink recursively.

Here's an example from my machine:

$ which firefox
/usr/bin/firefox

$ readlink -f $(which firefox)
/usr/lib/firefox-3.6.3/firefox.sh