| . (dot) |
Any character (byte) except newline |
| x |
The character 'x' |
| \\ |
The character '\' |
| \a |
The alert (bell) character (ASCII 0x07) |
| \b |
If this meta-symbol is within square brackets
[] or by itself, it will be treated as the backspace character (ASCII
0x08). For example, [\b] or \b
|
| If this meta-symbol is at the beginning (or
end) of a regular expression, it means any matched string of the regular
expression must check whether the left (or right) side of the matched string
is a boundary. For example,
|
|
| \bluck > left side must be the boundary |
|
| luck\b > right side must be the boundary |
|
| \bluck\b > both sides must be the boundary |
|
| If this meta-symbol appears in the middle of
a regular expression, it will cause a syntax error.
|
|
| \f |
The form-feed character (ASCII 0x0C) |
| \n |
The newline (line feed) character (ASCII 0x0A) |
| \r |
The carriage-return character (ASCII 0x0D) |
| \t |
The normal (horizontal) tab character (ASCII
0x09)
|
| \v |
The vertical tab character (ASCII 0x0B) |
| \n |
The character with octal value 0n (0 <=
n <= 7)
|
| \nn |
The character with octal value 0nn (0 <=
n <= 7)
|
| \mnn |
The character with octal value 0mnn (0 <=
m <= 3, 0 <= n <= 7)
|
| \xhh |
The character with a hexadecimal value 0xhh,
for example, \x20 means the space character
|
