Can you use regex as the identifier in a Bash case statement?

• A. Case statements do not support patterns.
• B. Yes, you can use regex.
• C. Only with a special flag.
• D. No, case uses globs, not regex.

Answer: (D)

Bash case statements rely on shell pattern matching rather than full regular expressions. The patterns you use in a case are glob patterns: * matches any string, ? matches a single character, and [set] matches a character class. You can enable extended globbing for more forms, but these remain glob patterns, not regex.

Because of that, you can’t write a case pattern that uses regular-expression syntax. If you need true regex matching, use the test form with the =~ operator, like [[ "$var" =~ regex ]], which applies a POSIX regular expression to the string. So the correct idea is that case uses globs, not regex.