Cheat Sheet
The commands you keep forgetting, with a one-line description and a real example you can copy - 384 across 26 tools. Pick a tool in the sidebar, or search across all of them.
Regex
The building blocks of regular expressions, with a concrete match each.| Command | What it does | Example |
|---|---|---|
. | Any single character (except newline). | a.c matches "abc", "a-c" |
\d | Any digit 0-9. | \d+ matches "42" in "order 42" |
\w | A word character: letter, digit, or underscore. | \w+ matches "user_1" |
\s | Any whitespace character. | \s+ matches the gap in "a b" |
^ | Anchor to the start of the line. | ^Error matches lines starting with "Error" |
$ | Anchor to the end of the line. | \.js$ matches "app.js" |
* | Zero or more of the previous token. | ab* matches "a", "ab", "abbb" |
+ | One or more of the previous token. | \d+ matches "2024" |
? | Zero or one (makes it optional). | colou?r matches "color" and "colour" |
{n,m} | Between n and m repetitions. | \d{2,4} matches "12" and "2024" |
[...] | Any one character from the set. | [aeiou] matches a single vowel |
[^...] | Any one character NOT in the set. | [^0-9] matches a non-digit |
(...) | Group and capture for reuse. | (\d{4})-(\d{2}) captures "2024" and "06" |
(?:...) | Group without capturing. | (?:ab)+ matches "abab" |
| | Alternation: match either side. | cat|dog matches "cat" or "dog" |
\b | A word boundary. | \bcat\b matches "cat" but not "category" |
\. | A literal dot (escaped). | \.com matches ".com" |