const regex = /Content-Transfer-Encoding: base64\s+(.*?)$/gmi;
// Alternative syntax using RegExp constructor
// const regex = new RegExp('Content-Transfer-Encoding: base64\\s+(.*?)$', 'gmi')
const str = `Content-Transfer-Encoding: base64
DQoNCg0KDQoNCg0KDQoNCg0KDQpbQiZRXTxodHRwOi8vd3d3LmRpeS5jb20+DQoNCg0KDQoNCg0K W2h0dHA6Ly9raW5nZmlzaGVyLnNjZW5lNy5jb20vaXMvaW1hZ2UvS2luZ2Zpc2hlci9pY29uX3N0 b3JlX2xvY2F0b3I/d2lkPTM2JmhlaT0zNiZxbHQ9MTAwXTxodHRwOi8vd3d3LmRpeS5jb20vZmlu ZC1hLXN0b3JlPg0KDQoNCg0KRmluZCBhIHN0b3JlPGh0dHA6Ly93d3cuZGl5LmNvbS9maW5kLWEt c3RvcmU+DQoNCg0KDQoNCkN1c3RvbWVyIFNlcnZpY2VzDQoNCjAzMzMgMDE0IDMzNTcNCg0KDQoN Cg0KDQoNCg0KDQoNCkluc3BpcmF0aW9uPGh0dHA6Ly93d3cuZGl5LmNvbS9pbnNwaXJhdGlvbi8w Lmlyb290Pg0KDQpQcm9qZWN0czxodHRwOi8vd3d3LmRpeS5jb20vcHJvamVjdHMvMi5wcm9vdD4N Cg0KU2hvcDxodHRwOi8vd3d3LmRpeS5jb20vc2hvcC8+DQoNCkhlbHAgJiBBZHZpY2U8aHR0cDov L3d3dy5kaXkuY29tL2hlbHAtYWR2aWNlLzEuaHJvb3Q+DQoNCk15IGFjY291bnQ8aHR0cDovL3d3 dy5kaXkuY29tL2N1c3RvbWVyL215X2FjY291bnQvPg0KDQoNCg0KDQoNCg0KDQoNCg0KRGVhciBC ZW4gUGF0b24NCg0KDQoNCg0KVGhhbmsgeW91IGZvciB5b3VyIG9yZGVyDQoNCg0KDQoNCg0KT3Jk ZXIgbnVtYmVyOg0KDQowMDYzMTA5MDU1DQoNCg0KDQpUb3RhbCBDb3N0Og0KDQrCozMuMjcNCg0K DQoNClRoYW5rIHlvdSBmb3Igb3JkZXJpbmcgZnJvbSBCJlEuIFlvdeKAmWxsIGZpbmQgZGV0YWls cyBvZiB5b3VyIG9yZGVyIGFuZCBkZWxpdmVyeSBvciBjb2xsZWN0aW9uIGluZm9ybWF0aW9uIGJl bG93LiBGb3IgaGVscCB3aXRoIHF1ZXN0aW9ucyBhYm91dCBvdXIgc2VydmljZSwgcGxlYXNlIHNl`;
// Reset `lastIndex` if this regex is defined globally
// regex.lastIndex = 0;
let m;
while ((m = regex.exec(str)) !== null) {
// This is necessary to avoid infinite loops with zero-width matches
if (m.index === regex.lastIndex) {
regex.lastIndex++;
}
// The result can be accessed through the `m`-variable.
m.forEach((match, groupIndex) => {
console.log(`Found match, group ${groupIndex}: ${match}`);
});
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions