H3C S5500-SI Series Operation Manual page 983

Character
+
|
_
-
[ ]
( )
\index
[^]
\<string
string\>
Meaning
Addition, used to match a
character or character group
one or multiple times before it
Vertical bar, used to match the
whole string on the left or right
of it
Underline. If it is at the
beginning or the end of a
regular expression, it equals ^
or $; in other cases, it equals
comma, space, round bracket,
or curly bracket.
Hyphen. It connects two values
(the smaller one before it and
the bigger one after it) to
indicate a range together with
[ ].
A range of characters, Matches
any character in the specified
range.
A character group. It is usually
used with "+" or "*".
Repeats a specified character
group for once. A character
group refers to the string in ()
before \. index refers to the
sequence number (starting from
1 from left to right) of the
character group before \: if only
one character group appears
before \, then index can only be
1; if n character groups appear
before index, then index can be
any integer from 1 to n.
Used to match any character
not in a specified range.
Used to match a character
string starting with string.
Used to match a character
string ending with string.
1-20
Remarks
For example, "zo+" can match "zo" and
"zoo", but not "z".
For example, "def|int" can only match a
character string containing "def" or "int".
For example, "a_b" can match "a b" or
"a(b"; "_ab" can only match a line
starting with "ab"; "ab_" can only match a
line ending with "ab".
For example, "1-9" means numbers from
1 to 9 (inclusive); "a-h" means from a to h
(inclusive).
For example, [16A] can match a string
containing any character among 1, 6,
and A; [1-36A] can match a string
containing any character among 1, 2, 3,
6, and A (with - being a hyphen).
"]" can be matched only when it is put at
the beginning of [ ] if it is used as a
common character in [ ], for example
[ ]string]. There is no such limit on "[".
For example, (123A) means a character
group "123A"; "408(12)+" can match
40812 or 408121212. But it cannot
match 408.
For example, (string)\1 means to repeat
string for once, and (string)\1 must
match a string containing stringstring;
(string1)(string2)\2 means to repeat
string2 for once, and (string1)(string2)\2
must match a string containing
string1string2string2;
(string1)(string2)\1\2 means to repeat
string1 for once first, and then repeat
string2 for once, and
(string1)(string2)\1\2 must match a string
containing string1string2string1string2.
For example, [^16A] means to match a
string containing any character except 1,
6 or A, and the string can also contain 1,
6 or A, but cannot contain these three
characters only. For example, [^16A]
can match "abc" and "m16", but not 1,
16, or 16A.
For example, "\<do" can match word
"domain" or string "doa".
For example, "do\>" can match word
"undo" or string "abcdo".