Regular expression quick start guide
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Ka-Lok Yeung (Talk | contribs) |
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Strip first 4 digits: | Strip first 4 digits: | ||
/([0-9]{4})([0-9]*)/\2/ | /([0-9]{4})([0-9]*)/\2/ | ||
+ | |||
+ | Strip # and 7 first digits: | ||
+ | /([#])([0-9]{7})([0-9]*)/\3/ | ||
== References == | == References == |
Revision as of 09:10, 23 December 2009
Regular Expression Pattern | Explanations |
---|---|
^ | Matches beginning of a line |
$ | Matches the end of a line |
\d | Matches a digit |
[characters] | Matches any single character between the brackets |
re1|re2 | Match either re1 or re2 |
re* | Matches zero or more occurrences of re |
re+ | Matches one or more occurrences of re |
re? | Matches zero or one occurrences of re |
Re{m,n} | Matches at least “m” and at most “n” occurrences of re |
(...) | Parentheses are used to group regular expressions |
\0, \1, \2, ... | Substitute the value matched by the nth grouped sub-expression, used in remapped fields. |
Here are some examples:
Add 2720 prefix:
/(\d+)/2720\1/
or
/([0-9]*)/2720\1/
Strip first 4 digits:
/([0-9]{4})([0-9]*)/\2/
Strip # and 7 first digits:
/([#])([0-9]{7})([0-9]*)/\3/