diff options
Diffstat (limited to 'node_modules/safe-regex/readme.markdown')
| -rw-r--r-- | node_modules/safe-regex/readme.markdown | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/node_modules/safe-regex/readme.markdown b/node_modules/safe-regex/readme.markdown new file mode 100644 index 0000000..83673ac --- /dev/null +++ b/node_modules/safe-regex/readme.markdown @@ -0,0 +1,65 @@ +# safe-regex + +detect potentially +[catastrophic](http://regular-expressions.mobi/catastrophic.html) +[exponential-time](http://perlgeek.de/blog-en/perl-tips/in-search-of-an-exponetial-regexp.html) +regular expressions by limiting the +[star height](https://en.wikipedia.org/wiki/Star_height) to 1 + +WARNING: This module merely *seems* to work given all the catastrophic regular +expressions I could find scouring the internet, but I don't have enough of a +background in automata to be absolutely sure that this module will catch all +exponential-time cases. + +[](https://ci.testling.com/substack/safe-regex) + +[](http://travis-ci.org/substack/safe-regex) + +# example + +``` js +var safe = require('safe-regex'); +var regex = process.argv.slice(2).join(' '); +console.log(safe(regex)); +``` + +``` +$ node safe.js '(x+x+)+y' +false +$ node safe.js '(beep|boop)*' +true +$ node safe.js '(a+){10}' +false +$ node safe.js '\blocation\s*:[^:\n]+\b(Oakland|San Francisco)\b' +true +``` + +# methods + +``` js +var safe = require('safe-regex') +``` + +## var ok = safe(re, opts={}) + +Return a boolean `ok` whether or not the regex `re` is safe and not possibly +catastrophic. + +`re` can be a `RegExp` object or just a string. + +If the `re` is a string and is an invalid regex, returns `false`. + +* `opts.limit` - maximum number of allowed repetitions in the entire regex. +Default: `25`. + +# install + +With [npm](https://npmjs.org) do: + +``` +npm install safe-regex +``` + +# license + +MIT |