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' "$USER"
Sourcing the script means to use the Bash source command to read all of the commands in a script into the current shell session and run them there. A source command to read in a script such as hello.bash might look like this:
bash$ source hello.bash Hello, bashuser!
This method behaves rather like a function, in that it runs the commands as if you had entered them from your own shell. Variable settings, directory changes, shell options, and other changes will apply to the current ...