|.||any one character|
|[^]||not include (e.g. [^A-C] is any one except for ABC)|
|\w||word = [A-Za-z0-9]|
|\W||inverse of \w|
A useful command
grep -rnw '/path/to/somewhere/' -e 'pattern'
- -r recursive
- -n line number
- -w word regexp
If you use Emacs, you can forget the command and use projectile. This is a project managing package which provides strong search ability with ag/rg (you can still choose grep though).
In Linux, fuzzy finding fzf is another interesting program.