E.4 Examples of regular expressions

character-string

Matches a line that contains the specified character string.

spring

spring has come.

Y

winter-summer-autumn-spring

Y

-----spring-----

Y

^character-string

Matches a line that begins with the specified character string.

^spring

spring has come.

Y

winter-summer-autumn-spring

N

-----spring-----

N

character-string$

Matches a line that ends with the specified character string.

spring$

spring has come.

N

winter-summer-autumn-spring

Y

-----spring-----

N

^character-string$

Matches a line that contains only the specified character string.

^spring$

spring has come.

N

winter-summer-autumn-spring

N

spring

Y

spring

N

^$

Matches a null line.

^$

Y

spring

N

. (period)

Matches any one character.

in.e

winter has come.

Y

mother of invention

Y

life is in everything

Y

eight nine ten

N

increasing population

N

s..ing

picnic in spring

Y

skiing in winter

Y

character*

Matches a character string in which the character immediately preceding * is included any number of times or no times.

ro*m

terminal

Y

cd-rom

Y

living room

Y

h.*n

This is a pen.

Y

That is an apple.

Y

regular-expression|regular-expression

Matches either the left-hand regular expression or the right-hand regular expression.

[0-9]+|apple

That is an apple.

Y

spring in 2009

Y

(regular-expressions)

Groups regular expressions. This method is used mainly when the | is used.

i(n.e|ng)

winter has come.

Y

interesting book

Y

[character-string]

Matches any of the characters in the character string specified in [ ].

[pr]

spring has come.

Y

today is monday.

N

[character-character]

Matches any of the characters within the specified range of character codes (when sorted in ascending order).

[a-i]

spring has come.

Y

[^character-character]

Matches any characters not within the specified range of character codes (when sorted in ascending order).

[^a-i]

spring has come.

Y

\special-character

Treats the specified special character as a normal character.

o\.h

<stdio.h>

Y

another man

N