Tag Archives: reference

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