Regular Expressions

evolvEd® allows for Regular Expressions in its search and replace functions listed under the Search Menu.
Regular expressions allow more complex search and replace functions to be performed in a single operation.
evolvEd uses Unix-style Regular Expressions (NFA Traditional), table below shows the syntax.

Symbol Function
\ Marks the next character as a special character. "n" matches the character "n". "\n" matches a linefeed or newline character.
^ Matches/anchors the beginning of line.
$ Matches/anchors the end of line.
* Matches the preceding character zero or more times.
+ Matches the preceding character one or more times.
. Matches any single character except a newline character.
(expression) Brackets or tags an expression to use in the replace command.A regular expression may have up to 9 tagged expressions, numbered according to their order in the regular expression.

The corresponding replacement expression is \x, for x in the range 1-9. Example: If (h.*o) (f.*s) matches "hello folks", $2 $1 would replace it with "folks hello".
[xyz] A character set. Matches any characters between brackets.
[^xyz] A negative character set. Matches any characters NOT between brackets.
\d Matches a digit character. Equivalent to [0-9].
\D Matches a nondigit character. Equivalent to [^0-9].
\f Matches a form-feed character.
\n Matches a linefeed character.
\r Matches a carriage return character.
\s Matches any white space including space, tab, form-feed, etc but not newline.
\S Matches any nonwhite space character but not newline.
\t Matches a tab character.
\v Matches a vertical tab character.
\w Matches any word character including underscore.
\W Matches any nonword character.

Examples

m.n matches "man", "men", "min" but not "moon".

Te+st matches "test", "teest", "teeeest" etc. BUT NOT "tst".

Te*st matches "test", "teest", "teeeest" etc. AND "tst".

[aeiou] matches every lowercase vowel
[,.?] matches a literal ",", "." or "?"
[0-9, a-z] matches any digit, or lowercase letter
[^0-9] matches any character except a digit (^ means NOT the following)

You may search for an expression A or B as follow:

"(John|Tom)"

This will search for an occurrence of John or Tom. There should be nothing between the two expressions.

You may combine A or B and C or D in the same search as follows:

"(John|Tom) (Smith|Jones)"

This will search for John or Tom followed by Smith or Jones.