grex

Regex generator from example strings

TLDR

Generate regex from examples

$ grex [foo] [bar] [baz]

Convert digits to `\d`

$ grex -d [test1] [test2]

Convert whitespace to `\s` and words to `\w`

$ grex -s -w [example1] [example2]

Case insensitive matching

$ grex -i [example1] [example2]

Generate with repetition detection

$ grex -r [aaab] [aaac]

Generate without start/end anchors

$ grex --no-anchors [examples...]

Read examples from file (one per line)

$ grex -f [examples.txt]

grex generates regular expressions from user-provided test strings. It analyzes the input examples and produces a regex that matches all of them. By default, the generated regex includes ^ and $ anchors.The tool supports various character class conversions (\d, \s, \w and their inverses), repetition detection, and case-insensitive matching. It is useful for quickly creating regexes without manual pattern analysis.

PARAMETERS

TEST-STRINGS

Example strings to generate regex from.

-d, --digits

Convert Unicode decimal digits to \d.

-D, --non-digits

Convert non-digit characters to \D.

-s, --spaces

Convert Unicode whitespace to \s.

-S, --non-spaces

Convert non-whitespace characters to \S.

-w, --words

Convert Unicode word characters to \w.

-W, --non-words

Convert non-word characters to \W.

-i, --ignore-case

Generate case-insensitive regex.

-e, --escape

Replace all non-ASCII characters with unicode escape sequences.

-r, --repetitions

Detect repeated substrings and convert to quantifier notation.

--no-anchors

Remove ^ and $ anchors (anchors are added by default).

--no-start-anchor

Remove the ^ start anchor only.

--no-end-anchor

Remove the $ end anchor only.

-f, --file FILE

Read test strings from a file (one per line).

--help

Display help information.

INSTALL

sudo pacman -S grex

sudo zypper install grex

brew install grex

nix profile install nixpkgs#grex

CAVEATS

Generated regex may be overly specific or general. Manual refinement often needed. Complex patterns may require additional examples.

HISTORY

grex was created by Peter M. Stahl as a command-line tool to simplify regex creation through example-based learning.