Pattern: Use of (..) instead of { ..; }
Issue: -
You appear to be using (..) to group test commands. This creates a subshell, making it unnecessarily slow. Avoid this by using { ..; } to group.
Be careful to note that unlike (..), this requires both a space after the { and a semicolon before the }.
For example, (cmd), (cmd;) and ( cmd ) are all valid, but {cmd}, {cmd;} and { cmd } are all syntax errors because they lack either or both of the spaces and semicolon. The correct form is { cmd; }
Example of incorrect code:
([ "$x" ] || [ "$y" ]) && [ "$z" ]Example of correct code:
{ [ "$x" ] || [ "$y" ]; } && [ "$z" ]