Interview › Scripting (Bash, Groovy)
How do you parse command-line options with getopts? [Intermediate]
Answer
getopts is Bash's built-in way to parse short command-line options. It iterates through options, sets the option name in a variable, and uses OPTARG for option values when the option requires an argument.
Technical explanation
The option string controls which options are valid; a colon after an option means it requires a value.
After parsing, shift $((OPTIND - 1)) removes processed options so positional arguments remain.
getopts handles short options like -e prod -v. For long options like --environment, many teams use a manual case loop or external getopt carefully.
Hands-on example
env="dev"
verbose=false
while getopts ":e:v" opt; do
case "$opt" in
e) env="$OPTARG" ;;
v) verbose=true ;;
:) echo "option -$OPTARG requires a value" >&2; exit 2 ;;
\?) echo "unknown option -$OPTARG" >&2; exit 2 ;;
esac
done
shift $((OPTIND - 1))
echo "env=$env verbose=$verbose remaining=$*"Preparing for an interview?
Check how well your resume matches the role with our free resume checker— match score, ATS check, and the skills you're missing.
More Scripting (Bash, Groovy) interview questions
- What is the purpose of the shebang line, and what does #!/bin/bash do? [Basic]
- What is the difference between sh and bash? [Basic]
- How do you make a script executable and run it? [Basic]
- What is the difference between running a script with./script.sh, bash script.sh, and source script.sh? [Basic]
- What does sourcing a script do differently from executing it? [Basic]
- How do you declare a variable in Bash, and why are spaces around = not allowed? [Basic]
- What is the difference between $var and ${var}? [Basic]
- What is the difference between single quotes and double quotes in Bash? [Basic]