regular expression tester
hints
| ^ | Beginning of string |
| $ | End of string |
| . | Any single character |
| n | Exactly one "n" |
| [abc] | A single character: a, b, or c |
| [a-d] | Any lowercase character between a and z |
| [K-O] | Any uppercase character between K and O |
| [a-zA-Z] | Any alphabetical character (both lowercase or uppercase) |
| [0-9] | Any number |
| [^a-d] | Negation: matches any single character but lowercase characters between a and d |
| () | Subexpression: parentheses group strings together |
| | | Alternation: matches either the subexpression to the left or to the right |
| (a|b) | Either a or b |
| \ | Escapes a special character for literal interpretation |
repetition operators
| {3} | Match exactly 3 occurences of the previous expression |
| {3,} | Match at least 3 or more occurences of the previous expression |
| {3,5} | Match at least 3 but no more than 5 occurences of the previous expression |
| * | Match 0 or more occurences of the previous expression - the same as {0,} |
| ? | Match 0 or 1 occurences of the previous expression - the same as {0,1} |
| + | Match 1 or more occurences of the previous expression - the same as {1,} |
character classes
| [[:alnum:]] | Any alphanumeric character - not the same as [a-zA-Z0-9]. This includes also locale set characters (e.g. á, ñ) |
| [[:alpha:]] | Any alphabetical character - includes locale set characters |
| [[:blank:]] | Space or tab |
| [[:cntrl:]] | Any control character (^x, ^c, ^h etc.) |
| [[:digit:]] | Any digit - the same as [0-9] |
| [[:graph:]] | Any non-blank character (not spaces, control characters etc.) |
| [[:lower:]] | Any lowercase English character - the same as [a-z] |
| [[:print:]] | Like [[:graph:]] but includes space character |
| [[:punct:]] | Punction and other characters (@, parentheses, ...) |
| [[:space:]] | Any whitespace character (space, tab, carriage return, new line, new page) |
| [[:upper:]] | Any lowercase English character - the same as [A-Z] |
| [[:xdigit]] | Any hexadecimal numeric - the same as [0-9a-fA-F] |
| [[:<:]] | Beginning of word |
| [[:>:]] | End of word |
metacharacters
| . | \ | ^ | $ | * | + |
| ? | | | ( | ) | [ | { |
Metacharacters need to be escaped (i.e. preceded by \) if you want to free them from their special meaning. No escaping is neccessary inside square brackets – everything between [] is interpreted literally.
further reading
Comments
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Posted by naisioxerloro on November 11 2007 16:52:43
Hi. Good design, who make it?
Posted by Richard Laffers on November 11 2007 20:58:05
Thanks. The design is by me.
Posted by poelveviedo on December 12 2007 18:46:32
Very good site! I like it! Thanks! <a href=http:> Best Links </a>
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