Sample Regular Expressions

Previous Up Next

Expression

Meaning

^abc

Match "abc" at beginning of line

abc$

Match "abc" at end of line

^abc$

Match the line "abc" exactly

^\s*abc

Match "abc" at beginning of line, but allow leading whitespace

^\s*end;?\s*$

Match a line containing only "end" or "end;" with leading or trailing whitespace

abc|def

Matches either "abc" or "def"

a(b|c)d

Matches "abd" or "acd"

a(b|c)d\1

Matches "abdb" or "acdc", but it does not match "abdc"

 

Control characters used in above samples

Character

Meaning

^

Beginning of line

$

End of line

\s

Whitespace (a tab or space)

*

Zero or more of the preceding character

?

Preceding character is optional

|

Alternative expression

( )

Subexpressions

\1

Back reference to 1st subexpression

 

See also

Regular Expression Reference