.REGEX_CHAR

Sets the escape character used to indicate special sequences

\ (backslash)

.REGEX_WILD

Sets the wildcard character that matches any single character

. (period)

[1]

character

A normal character matches itself. Special characters: wild \ [ ] * + ^ $

[2]

wild

The wildcard character, wild, matches any character.

[3]

\

The escape character makes special characters literal: \wild is literal wild, \\ is literal \, \[ is literal [, and so on. The only exceptions are that \( and \) are special. See [7] below.

[4]

[ set ]

Matches one character in set. If the first character in set is ^, this form matches characters not in set. A range start-end means characters from start to end. The characters ] and - aren't special if they appear as the first characters in set. \t matches a tab character. For example:

Set

[a-zA-Z@]

[^]-]

[^A-Z]

[<SPACE> \t]

Matches

Lowercase and uppercase alphabetic, or @

Neither ] nor -

Not uppercase alphabetic

A space or tab (that is, white space)

[5]

form*

Any regular expression form labeled [1] to [4] followed by the closure character * matches zero or more of the form.

[6]

form+

+ is like *, except it matches one or more of the form.

[7]

\( form \)

A regular expression in the form [1] to [10], enclosed as \( form \) matches what form matches. The substring matched by form can be referenced with a tag (see below).

[8]

\1 ... \9

Matches a previously tagged regular expression (see [7]).

[9]

form1form2

A composite regular expression form1form2, where form1 and form2 are in the form [1] to [9], matches the longest match of form1 followed by a match of form2.

[10]

^ and $

A regex starting with ^ and/or ending with $ restricts the regex to the beginning of the line and/or the end of line. Elsewhere in the regex, ^ and $ are ordinary characters.