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Symbol
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Function
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^
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Only match the beginning of a string.
"^A" matches first "A" in "An A+ for Anita."
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$
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Only match the ending of a string.
"t$" matches the last "t" in "A cat in the hat"
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\b
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Matches any word boundary
"ly\b" matches "ly" in "possibly tomorrow."
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\B
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Matches any non-word boundary
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Symbol
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Function
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Alphanumeric
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Matches alphabetical and numerical characters literally.
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\n
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Matches a new line
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\f
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Matches a form feed
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\r
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Matches carriage return
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\t
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Matches horizontal tab
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\v
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Matches vertical tab
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\?
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Matches ?
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\*
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Matches *
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\+
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Matches +
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\.
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Matches .
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\|
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Matches |
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\{
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Matches {
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\}
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Matches }
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\\
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Matches \
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\[
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Matches [
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\]
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Matches ]
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\(
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Matches (
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\)
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Matches )
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\xxx
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Matches the ASCII character expressed by the octal number xxx.
"\50" matches "(" or chr (40).
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\xdd
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Matches the ASCII character expressed by the hex number dd.
"\x28" matches "(" or chr (40).
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\uxxxx
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Matches the ASCII character expressed by the UNICODE xxxx.
"\u00A3" matches "£".
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Symbol
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Function
|
|
[xyz]
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Match any one character enclosed in the character set.
"[a-e]" matches "b" in "basketball".
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[^xyz]
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Match any one character not enclosed in the character set.
"[^a-e]" matches "s" in "basketball".
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.
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Match any character except \n.
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\w
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Match any word character. Equivalent to [a-zA-Z_0-9].
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\W
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Match any non-word character. Equivalent to [^a-zA-Z_0-9].
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\d
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Match any digit. Equivalent to [0-9].
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\D
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Match any non-digit. Equivalent to [^0-9].
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\s
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Match any space character. Equivalent to [ \t\r\n\v\f].
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\S
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Match any non-space character. Equivalent to [^ \t\r\n\v\f].
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Symbol
|
Function
|
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{x}
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Match exactly x occurrences of a regular expression.
"\d{5}" matches 5 digits.
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{x,}
|
Match x or more occurrences of a regular expression.
"\s{2,}" matches at least 2 space characters.
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{x,y}
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Matches x to y number of occurrences of a regular expression.
"\d{2,3}" matches at least 2 but no more than 3 digits.
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?
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Match zero or one occurrences. Equivalent to {0,1}.
"a\s?b" matches "ab" or "a b".
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*
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Match zero or more occurrences. Equivalent to {0,}.
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+
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Match one or more occurrences. Equivalent to {1,}.
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|
Symbol
|
Function
|
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()
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Grouping a clause to create a clause. May be nested. "(ab)?(c)" matches "abc" or "c".
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|
|
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Alternation combines clauses into one regular expression and then matches any of the individual clauses.
"(ab)|(cd)|(ef)" matches "ab" or "cd" or "ef".
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Symbol
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Group
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|
()\n
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Matches a clause as numbered by the left parenthesis
"(\w+)\s+\1" matches any word that occurs twice in a row, such as "hubba hubba."
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Symbol
|
Function
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()
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Stores the enclosed search result in the next buffer
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|
Symbol
|
Function
|
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$1
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Uses the content of the first buffer
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