# cidr-regex [](https://www.npmjs.org/package/cidr-regex) [](https://www.npmjs.org/package/cidr-regex) [](https://travis-ci.org/silverwind/cidr-regex) > Regular expression for matching IP addresses in CIDR notation ## Install ```sh $ npm install --save cidr-regex ``` ## Usage ```js const cidrRegex = require('cidr-regex'); // Contains a CIDR IP address? cidrRegex().test('foo 192.168.0.1/24'); //=> true // Is a CIDR IP address? cidrRegex({exact: true}).test('foo 192.168.0.1/24'); //=> false cidrRegex.v6({exact: true}).test('1:2:3:4:5:6:7:8/64'); //=> true 'foo 192.168.0.1/24 bar 1:2:3:4:5:6:7:8/64 baz'.match(cidrRegex()); //=> ['192.168.0.1/24', '1:2:3:4:5:6:7:8/64'] ``` ## API ### cidrRegex([options]) Returns a regex for matching both IPv4 and IPv6 CIDR IP addresses. ### cidrRegex.v4([options]) Returns a regex for matching IPv4 CIDR IP addresses. ### cidrRegex.v6([options]) Returns a regex for matching IPv6 CIDR IP addresses. #### options.exact Type: `boolean`<br> Default: `false` *(Matches any CIDR IP address in a string)* Only match an exact string. Useful with `RegExp#test()` to check if a string is a CIDR IP address. ## Related - [is-cidr](https://github.com/silverwind/is-cidr) - Check if a string is an IP address in CIDR notation - [is-ip](https://github.com/sindresorhus/is-ip) - Check if a string is an IP address - [ip-regex](https://github.com/sindresorhus/ip-regex) - Regular expression for matching IP addresses ## License © [silverwind](https://github.com/silverwind), distributed under BSD licence Based on previous work by [Felipe Apostol](https://github.com/flipjs)