The basic one supports matching such as these:

Simple text match

Note you don’t need to add any wildcard before or after.

$ grep 'foo' PATH

Simple regex

These are all allowed in simple regex.

Whitespace.

$ grep '\sfoo' PATH

Blank line.

$ grep '^$' PATH

$ grep '^[a-z]' Makefile

Using a globstar.

Note dot matches anything, not a literal dot.

$ grep 'go *.' go.mod

Matches:

module github.com/MichaelCurrin/go-project-template

go 1.15

github.com/cpuguy83/go-md2man/v2 v2.0.0 // indirect

Using escaped dot.

$ grep 'go \w*\.' go.mod

go 1.15