Linux Pocket Guide, 2nd Edition

Name

egrep — stdin  stdout  - file  -- opt  --help  --version

Synopsis

egrep [options] pattern [files]

The egrep command is just like grep, but uses a different (“extended”) language for regular expressions. It’s the same as grep -E.

Table 1-2. Regular expressions for grep and egrep

Regular expression		Meaning
Plain	Extended
.		Any single character.
[...]		Match any single character in this list.
[^...]		Match any single character NOT in this list.
(...)		Grouping.
\|	|	Or.
^		Beginning of a line.
$		End of a line.
\<		Beginning of a word.
\>		End of a word.
[:alnum:]		Any alphanumeric character.
[:alpha:]		Any alphabetic character.
[:cntrl:]		Any control character.
[:digit:]		Any digit.
[:graph:]		Any graphic character.
[:lower:]		Any lowercase letter.
[:print:]		Any printable character.
[:punct:]		Any punctuation mark.
[:space:]		Any whitespace character.
[:upper:]		Any uppercase letter.
[:xdigit:]		Any hexadecimal digit.
*		Zero or more repetitions of a regular expression.
\+	+	One or more repetitions of a regular expression.
\?	?	Zero or one occurrence of a regular expression.
\{n \}	{n }	Exactly n repetitions of a regular expression.
\{ n ,\}	{n ,}	n or more repetitions of a regular expression.
\{ n , m \}	{ n , m }	Between n and m (inclusive) repetitions of a regular expression, n < m.
\c		The character c literally, even if c is a special regular expression character. For example, ...