PATH

What is PATH

When you wish to install programs into other locations on your host, but be able to execute them easily without specifying their exact location. This can be easily done by adding a directory to your $PATH.

View PATH

echo $PATH

Install packages and add to path

1. temporarily set path export PATH=<your-dir>:$PATH
2. permenantly set path: add export PATH=<your-dir>:$PATH in .bashrc. Then restart the terminal.

which vs whereis

which: returns the pathnames of the file which would be executed in the current enviroment

whereis: searches for binary/source and manual page files.

For example,

whereis php => php: /usr/bin/php /usr/share/php /usr/share/man/man1/php.1.gz

# the php is executable, and some other stuff (e.g., man pages)

which php => /usr/bin/php
# returns only the php executable.