JarCastingsafe-regex
detect potentially catastrophic exponential-time regular expressions by limiting the 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.
example
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
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 do:
npm install safe-regex
license
MIT