Scripts

The third method of creating your own commands with Bash is to put them in a script: a file that you can arrange for bash to interpret and execute from the filesystem by name.

What a "script" means to Bash can mean many different things depending on context. In this book, we'll focus on scripts stored as executable program files on our filesystem, external to the Bash process itself.

Scripting methods

There are three general ways to run a script file in Bash: sourcing it, providing it to bash as input, and as a standalone script. For the following examples, we'll use the hello.bash script, with the following contents:

printf 'Hello, %s!\n' "$USER"

Sourcing the script means to...