\cx

Matches the control character indicated by x. For example, \cM matches a Control-M or carriage return character. The value of x must be in the range of A-Z or a-z. If not, c is assumed to be a literal 'c' character.

\f

Matches a form-feed character. Equivalent to \x0c and \cL.

\n

Matches a newline character. Equivalent to \x0a and \cJ.

\r

Matches a carriage return character. Equivalent to \x0d and \cM.

\s

Matches any white space character including space, tab, form-feed, and so on. Equivalent to [\f\n\r\t\v].

\S

Matches any non-white space character. Equivalent to [^ \f\n\r\t\v].

\t

Matches a tab character. Equivalent to \x09 and \cI.

\v

Matches a vertical tab character. Equivalent to \x0b and \cK.