VoLANs VoSS12, Руководство администратора

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AdminGuide-Voss12-1.docx 119
B. Perl Regular Expression
In this section, the Perl Regular Expression which will be used for Dialplan will be
described.
■ Character class
Char Description Example Example Description
[ ]
Character class [0-9] One digit number from 0 to 9
[^]
Negated character class [^0-9] A character excluding number.
■ Common character class
Char Description Example Example Description
\d
One digit of decimal [0-9] \d9 2 digits number ends with 9, such as 09, 59..
\D
One digit of character, not
decimal \D9 2 digits character end with 9, such as A9, r9…
■ Alternation meta-character
Char Description Example Example Description
|
‘or’ either left or right digit of | (0|1|6) One digit either 0, 1, or 6
■ Grouping meta-character
Char Description Example Example Description
( )
A group, it is recognized as a
unit. (01)(0|1|6) Either 010, 011, or 016
■ Extracting meta-character
Extracting meta-character means that extract meta-character which matches by
using () and each value will be pointed with Matching variable such as $1, $2 …
Char Description Example Example Description
$
Use the value which matches
with ( ) value.
(01)(2) $1 has 01, $2 has 2
■ Matching Repetitions
Char Description Example Example Description
?
Nothing or use the value once (012)? Nothing or 012 (used only once)
*
Nothing or use the value more
than twice. (012)* Nothing or 012, 012012, 012012012 ……
Difference between ? and * is that
+
Using more than once (012)+ 012 or 012012, 012012012 ……
x{n}
Use x multiplied by n (012){2} 012012, use 012 twice
x{n,}
Use x at least n times (012){2,} 012012012, 012012012012, ….
x{n,m}
Use min n time and man m
times. (012){2,4} 012012012, more than twice, less than 4 times.
■ POSIX Character class