working with regex is always painful. most of the time developers end up in copy pasting regular expressions from stack-overflow or other sites. Although this satisfies the needs of most common requirements, it is good to have an idea of what the regex is doing and testing it.
I find following tools very helpful while working with regular expressions.
- Any text editor or IDE
most of the modern ides and text editors come with a good regular expression support for searching text.
This is one of my favourite developer tool. Regulex helps to visualize the regular expression
If you want to write, test & play with regex this is a good site. It also has good regex documentation.