Appendix A - Regular Expression Syntax used by Ycopy's Copy Rules List
For more information see the black list feature.
The following table lists the regular expression metacharacters understood by Ycopy.
Metacharacter
Meaning
.
Matches any single character.
[ ]
Indicates a character class. Matches any character inside the brackets (for example, [abc] matches "a", "b", and "c").
^
If this metacharacter occurs at the start of a character class, it negates the character class. A negated character class matches any character except those inside the brackets (for example, [^abc] matches all characters except "a", "b", and "c").
If ^ is at the beginning of the regular expression, it matches the beginning of the input (for example, ^[abc] will only match input that begins with "a", "b", or "c").
-
In a character class, indicates a range of characters (for example, [0-9] matches any of the digits "0" through "9").
?
Indicates that the preceding expression is optional: it matches once or not at all (for example, [0-9][0-9]? matches "2" and "12").
+
Indicates that the preceding expression matches one or more times (for example, [0-9]+ matches "1", "13", "666", and so on).
*
Indicates that the preceding expression matches zero or more times.
??, +?, *?
Non-greedy versions of ?, +, and *. These match as little as possible, unlike the greedy versions which match as much as possible. Example: given the input "<abc><def>", <.*?> matches "<abc>" while <.*> matches "<abc><def>".
( )
Grouping operator. Example: (\d+,)*\d+ matches a list of numbers separated by commas (such as "1" or "1,23,456").
{ }
Indicates a match group.
\
Escape character: interpret the next character literally (for example, [0-9]+ matches one or more digits, but [0-9]\+ matches a digit followed by a plus character). Also used for abbreviations (such as \a for any alphanumeric character; see table below).
If \ is followed by a number n, it matches the nth match group (starting from 0). Example: <{.*?}>.*?</\0> matches "<head>Contents</head>".
$
At the end of a regular expression, this character matches the end of the input. Example: [0-9]$ matches a digit at the end of the input.
|
Alternation operator: separates two expressions, exactly one of which matches (for example, T|the matches "The" or "the").
!
Negation operator: the expression following ! does not match the input. Example: a!b matches "a" not followed by "b".
Abbreviations
Ycopy can handle abbreviations, such as \d instead of [0-9]. The abbreviations are provided by the character traits class passed in the CharTraits parameter. The predefined character traits classes provide the following abbreviations.
