| Character |
Usage |
| * |
Matches the previous character
zero or more times |
| + |
Matches the previous character
one or more times |
| ? |
Matches the previous character
zero or one times |
| . |
Matches any single character
except the newline |
| ^ |
Matches the start of the
input |
| $ |
Matches the end of the input
|
| x|y |
Matches either first or
second character listed |
| (pattern) |
Matches pattern |
| {number} |
Matches exactly number
times |
| {number,} |
Matches number, or
more, times (note comma) |
| {num1, num2} |
Matches at least num1
and at most num2 times |
| [abc] |
Matches any character listed
between the [ ] |
| [^abc] |
Matches all characters except
those listed between the [ ] |
| [a-e] |
Matches any characters in
the specified range (a,b,c,d,e) |
| [^K-Q] |
Matches all characters except
in the specified range |
| \ |
Signifies that the next
character is special or a literal. |
| \b |
Matches only on a word boundary
|
| \B |
Matches only inside a word
|
| \d |
Matches only on a digit
|
| \D |
Matches only on a non-digit
|
| \f |
Matches only on a form feed
character |
| \n |
Matches only on a new line
|
| \r |
Matches only on a carriage
return |
| \s |
Matches only on a blank
space |
| \S |
Matches only on nonblank
spaces |
| \t |
Matches only on a tab |
| \v |
Matches only on a vertical
tab |
| \w |
Matches only on A to Z,
a to z, 1 to 9, and _ |
| \W |
Matches characters other
than A to Z, a to z, 1 to 9, and _ |
| \number |
Matches any positive number
|
| \octal |
Matches any octal number
|
| \xhex |
Matches any hexadecimal
number (x is required) |
