HP A5830 Series Configuration Manual page 17

Character Meaning
Starting sign. string only appears at the
^string
beginning of a line.
Ending sign. string only appears at the end
string$
of a line.
Matches any single character, such as a
. single character, a special character, and a
blank.
Matches the preceding character or
*
character group zero or multiple times.
Matches the preceding character or
+
character group one or multiple times
Matches the preceding or succeeding
|
character string
If it is at the beginning or the end of a
regular expression, it equals ^ or $. In
_
other cases, it equals comma, space, round
bracket, or curly bracket.
Connects two values (the smaller one before
- it and the bigger one after it) to indicate a
range together with [ ].
Matches a single character contained
[ ]
within the brackets.
A character group. It is usually used with
( )
"+" or "*."
Repeats the character string specified by
the index. A character string refers to the
string within () before \. index refers to the
sequence number (starting from 1 from left
\index to right) of the character group before \. If
only one character group appears before
\, index can only be 1; if n character
groups appear before index, index can be
any integer from 1 to n.
Remarks
For example, regular expression "^user" only
matches a string beginning with "user," not
"Auser."
For example, regular expression "user$" only
matches a string ending with "user," not "userA."
For example, "s" matches both "as" and "bs."
For example, "zo*" matches "z" and "zoo;"
"(zo)*" matches "zo" and "zozo."
For example, "zo+" matches "zo" and "zoo," but
not "z."
For example, "def|int" only matches a character
string containing "def" or "int."
For example, "a_b" matches "a b" or "a (b; ;"
"_ab" only matches a line starting with "ab;"
"ab_" only matches a line ending with "ab."
For example, "1-9" means 1 to 9 (inclusive); "a-h"
means a to h (inclusive).
For example, [16A] matches a string containing
any character among 1, 6, and A; [1-36A]
matches a string containing any character among
1, 2, 3, 6, and A. The character (-) is a hyphen.
"]" can only be matched as a common character
when it is put at the beginning of characters
within the brackets, for example [ ]string]. There is
no such limit on "[."
For example, (123A) means a character group
"123A;" "408(12)+" matches 40812 or
408121212. But it does not match 408.
For example, (string)\1 repeats string, and a
matching string must contain stringstring.
(string1)(string2)\2 repeats string2, and a
matching string must contain
string1string2string2. (string1)(string2)\1\2
repeats string1 and string2 respectively, and a
matching string must contain
string1string2string1string2.
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