In Bash scripting, ‘test’ and ‘[[‘ are used for conditional expressions. The ‘test’ command is a traditional Unix utility that evaluates an expression and returns an exit status of 0 (true) or 1 (false). It supports fewer features compared to ‘[[‘.
On the other hand, ‘[[‘ is a keyword in Bash that provides more advanced functionality than ‘test’. It allows pattern matching with regular expressions, string comparison without quoting issues, and logical AND/OR operations without needing to use multiple ‘test’ commands. Additionally, it does not require escaping of parentheses when performing arithmetic comparisons.
However, ‘[[‘ is not POSIX compliant, meaning scripts using it may not be portable across different shells. In contrast, ‘test’ is POSIX compliant and thus ensures better portability.
