To use a library of functions in a Bash script, which command imports the functions into your script?

• A. import filename
• B. source filename
• C. load filename
• D. include filename

Answer: (B)

Bringing a library of functions into a Bash script is done by loading its contents into the current shell so the functions become available to the rest of the script. The source command reads and executes the file in the current shell environment, which pulls in any function definitions and variables defined there. For example, if lib.sh defines a function greet, using source lib.sh (or the equivalent . lib.sh) makes greet available in your script. If you instead run the file as a separate process, those definitions live only in that subshell and won’t be accessible to your script. So source is the right tool because it imports the definitions into the current shell context.