A number of useful non-printing characters are occasionally used. The table below shows the escape sequences used to represent those non-printing characters:
Character | Meaning |
\cx | Matches the control character indicated by x. For example, \cM matches a Control-M or a 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. |
\n | Matches a newline character. |
\r | Matches a carriage return character. |
\s | Matches any white space character including space, tab, form-feed, etc. |
\S | Matches any non-white space character. |
\t | Matches a tab character. |
\v | Matches a vertical tab character. |
x represents a character in the range A-Z or a-z.