Tag Archives: grep

Regex – Grep reference

 

Regex operator

Meaning

.

 Matches any single character.

?

 The preceding item is optional and will be matched, at most, once.

*

 The preceding item will be matched zero or more times.

+

 The preceding item will be matched one or more times.

{N}

 The preceding item is matched exactly N times.

{N,}

 The preceding item is matched N or more times.

{N,M}

 The preceding item is matched at least N times, but not more than M times.

–

 Represents the range if it’s not first or last in a list or the ending point of a range in a list.

^

 Matches the empty string at the beginning of a line; also represents the characters not in the range of a list.

$

 Matches the empty string at the end of a line.

\b

 Matches the empty string at the edge of a word.

\B

 Matches the empty string provided it’s not at the edge of a word.

\<

 Match the empty string at the beginning of word.

\>

 Match the empty string at the end of word.

(a|b)

 Match a or b

[abc]

 Range (a or b or c)

[^abc]

 NOT a or b or c

[a-z]

 Any letter (lowercase) from a to z

[A-Z]

 Any letter (uppercase) from a to z

[a-zA-Z]

 Any letter (upper and lowercase) from a to z

[0-9]

 Any digit from 0 to 9

A most exhaustive cheat sheet is available here