Regex

Regex (regular expressions) is such an amazing technology. It’s the most popular (and certainly powerful) text search engine.

Links

• As a learning resource, RegexOne guides you with excercises and is a great pratise tool.
• regex tutorials has a tutorial and nice excercises too.
• regexr.com is my goto website for testing expressions. Regex101 is a close second website if you prefer something different.
• Visually, this Dev.to guide is brief and to the point.
• If you want an more advanced documentation, regular-exresions.info may help advanced users.
• Are you a visual person? try this regex diagram generator. It’s very powerful!

How to

• Match all the caracters between 2 strings

# expression
(?<=This is)(.*)(?=sentence)
# this matches
This is "just a simple" sentence

The pattern looked closely:

(?<=\s|^)         #to look behind the match
(stackoverflow)   #the string you want. () optional
(?=\s|$)          #to look ahead.

source: StackOverflow

• You can even use regex in CSS

Apps

• For CLI, ripgrep is king. It also has ripgrep-all (unrelated to rg) that search among pdf, docx, sqlite, jpg, movie subtitles and more.
  • you have the guide here
• Do you want a GUI? here. You are welcome.
• If you want to go the other way, you can provide the cases, and grex will infer the regex expression