BUT - As far as resources for building out the regex patterns, I use regexpal.com and a copy of this https://cheatography.com/davechild/cheat-sheets/regular-expressions/pdf/ printed out beside me. Once you get into it, the power of subgroups, and lookahead/behind processing beats some of the mental gymnastics you would need to go to code it out in your language of choice. Source: about 2 years ago

Spend an afternoon really diving into it, bookmark regexpal.com, and call it a day IMO. Source: about 2 years ago

i’m a professional developer and I just relearn it every time I need it, which is about once or twice a year, but depending on someone’s specialty they may swim around in it all day. It can get really complicated. https://regexpal.com is where I kick it around testing until it works. Source: about 2 years ago

Hello, I have a question about sites like DeHashed.com, snusbase.com and intelx.io. Source: over 1 year ago

So if that is true, how could I go to the sites like https://intelx.io , https://dehashed.com/ ,https://snusbase.com/ and type email address that has been in a breach and obtain possible password and username sometimes for free, and sometimes for a couple of bucks? If what the OP of the linked post says is true. These platforms should not be legal, or am I missing something? Source: over 2 years ago

Usually it depends on where it will end up, you'll have to look through multiple different companies that pay to collect this information. Haveibeenpwned is a really great indicator to see the basics of where your information has been leaked through, but depending on the breach I'd recommend http://snusbase.com to get more details about what was contained in those databases. Source: almost 3 years ago

My favorites are theses 3, and are the most updated & fastest updated. - https://pwndb2am4tzkvold.onion.ws/ - https://snusbase.com/ - Dehashed.com (very nice but not free :/). Source: about 3 years ago