# grex > Generate `regex`s. > More information: . - Generate a simple `regex`: `grex {{string1 string2 ...}}` - Generate a case-insensitive `regex`: `grex {{[-i|--ignore-case]}} {{string1 string2 ...}}` - Replace digits with `\d`: `grex {{[-d|--digits]}} {{string1 string2 ...}}` - Replace Unicode word character with `\w`: `grex {{[-w|--words]}} {{string1 string2 ...}}` - Replace spaces with `\s`: `grex {{[-s|--spaces]}} {{string1 string2 ...}}` - Detect repeating patterns in the input and shorten them using {min,max} quantifiers: `grex {{[-r|--repetitions]}} {{string1 string2 ...}}` - Generate `regex` of test cases (separated by newline) from a file: `grex {{[-f|--file]}} {{path/to/file}}` - Do not generate anchors and non-capture groups: `grex --no-anchors {{[-g|--capture-groups]}} {{string1 string2 ...}}`