Perl Regular Expression

 

Simple Example of Perl Regular Expression:

 

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apple -> will match 'apple tree', 'apples', 'pineapple' ... any text containing 'apple'

 

^ -> match start of text

 

$ -> match end of text

 

^apple$ -> match the whole word 'apple'

 

. -> match any single character

 

.* -> match 0 or more characters

 

.+ -> match 1 or more characters

 

.? -> match 0 or 1 character

 

.{n} -> match text with n characters

 

.{n,} -> match text with n or more characters

 

.{n,m} -> match text with n to m characters

 

(abc)* -> match blank, abc, abcabc, abcabcabc, ...

 

(abc)+ -> match abc, abcabc, abcabcabc, ...

 

[abcd] -> match a, b, c or d

 

[^abc] -> match any single character except a, b, c

 

\d -> match any single digit 0,1,2,...9

 

\D -> match any non-digit character

 

\w -> match any single word letter a,b,c...z,A,B,C,...Z

 

\W -> match any non-word letter

 

\s -> match space, table or return

 

\S -> match any character except space, table, return

 

\d+ -> match one or more digits

 

\w* -> match 0 or more word letters

 

a|b -> match a or b

 

\t -> match table

 

\n -> match return

 

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Refer to http://perldoc.perl.org/perlre.html if you want to learn more about Perl Regular Expression.