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13 definitions found
From The Free On-line Dictionary of Computing (27 SEP 03) : [ foldoc ]
regular expression
1. (regexp, RE) One of the wild
card patterns used by Unix utilities such as grep, sed
and awk and editors such as vi and Emacs. These use
conventions similar to but more elaborate than those described
under glob. A regular expression is a sequence of
characters with the following meanings:
An ordinary character (not one of the special characters
discussed below) matches that character.
A backslash (\) followed by any special character matches the
special character itself. The special characters are:
"." matches any character except NEWLINE; "RE*" (where
the "*" is called the "{Kleene star") matches zero
or more occurrences of RE. If there is any choice, the
longest leftmost matching string is chosen, in most
regexp flavours.
"^" at the beginning of an RE matches the start of a line and
"$" at the end of an RE matches the end of a line.
[string] matches any one character in that string. If the
first character of the string is a "^" it matches
any character (except NEWLINE, in most regexp flavours)
and the remaining characters in the string. "-" may be used
to indicate a range of consecutive ASCII characters.
\( RE \) matches whatever RE matches and \n, where n is a
digit, matches whatever was matched by the RE between the nth
\( and its corresponding \) earlier in the same RE. In
many flavours ( RE ) is used instead of \( RE \)
The concatenation of REs is a RE that matches the
concatenation of the strings matched by each RE.
\< matches the beginning of a word and \> matches the end of a
word. In many flavours of regexp, \> and \< are replaced by
"\b", the special character for "word boundary".
RE\{m\ matches m occurences of RE. RE\{m,\} matches m or
more occurences of RE. RE\{m,n\ matches between m and n
occurences.
The exact details of how regexp will work in a given
application vary greatly from flavour to flavour. A comprehensive
survey of regexp flavours is found in Friedl 1997 (see below).
[Jeffrey E.F. Friedl, "{Mastering Regular
http://enterprise.ic.gc.ca/~jfriedl/regex/index.html)" rel="nofollow">Expressions(http://enterprise.ic.gc.ca/~jfriedl/regex/index.html),
O'Reilly, 1997.]
2. Any description of a pattern composed from combinations
of symbols and the three operators:
Concatenation - pattern A concatenated with B matches a match
for A followed by a match for B.
Or - pattern A-or-B matches either a match for A or a match
for B.
Closure - zero or more matches for a pattern.
The earliest form of regular expressions (and the term itself)
were invented by mathematician Stephen Cole Kleene in the
mid-1950s, as a notation to easily manipulate "regular sets",
formal descriptions of the behaviour of finite state
machines, in regular algebra.
[S.C. Kleene, "Representation of events in nerve nets and
finite automata", 1956, Automata Studies. Princeton].
[J.H. Conway, "Regular algebra and finite machines", 1971, Eds
Chapman & Hall].
[Sedgewick, "Algorithms in C", page 294].
(1997-08-03)
From English Wiktionary: All languages (2023-07-27) : [ dictinfo.com:wikt-en-ALL-2023-07-27 ]
regular expression
n.
1 (lb en comptheory) A concise description of a regular formal
language with notations for concatenation, alternation, and iteration
(repetition) of subexpressions.
2 (lb en computing more generally) Any pattern for text matching or
searching, frequently offering more or less functionality than a
theoretical regular expression.
From English Wiktionary: English language only (2023-07-27) : [ dictinfo.com:wikt-en-en-2023-07-27 ]
regular expression
n.
1 (lb en comptheory) A concise description of a regular formal
language with notations for concatenation, alternation, and iteration
(repetition) of subexpressions.
2 (lb en computing more generally) Any pattern for text matching or
searching, frequently offering more or less functionality than a
theoretical regular expression.
From English Wiktionary: Western, Greek, and Slavonic languages only (2023-07-27) : [ dictinfo.com:wikt-en-Western_Greek_Slavonic-2023-07-27 ]
regular expression
n.
1 (lb en comptheory) A concise description of a regular formal
language with notations for concatenation, alternation, and iteration
(repetition) of subexpressions.
2 (lb en computing more generally) Any pattern for text matching or
searching, frequently offering more or less functionality than a
theoretical regular expression.
From English Wiktionary: Western languages only (2023-07-27) : [ dictinfo.com:wikt-en-Western-2023-07-27 ]
regular expression
n.
1 (lb en comptheory) A concise description of a regular formal
language with notations for concatenation, alternation, and iteration
(repetition) of subexpressions.
2 (lb en computing more generally) Any pattern for text matching or
searching, frequently offering more or less functionality than a
theoretical regular expression.
From Finnish Wiktionary: All languages (2023-07-27) : [ dictinfo.com:wikt-fi-ALL-2023-07-27 ]
regular expression
Englanti n.
(''IT'') säännöllinen lauseke
From English-Czech dicts.info/FreeDict Dictionary ver. 0.1.3 : [ freedict:eng-ces ]
regular expression /ɹˈɛɡjʊləɹ ɛkspɹˈɛʃən/
[it] regulární výraz
From Eurfa Saesneg, English-Welsh Eurfa/Freedict dictionary ver. 0.2.3 : [ freedict:eng-cym ]
regular expression /ɹˈɛɡjʊləɹ ɛkspɹˈɛʃən/
mynegiad rheolaidd
From English - German Ding/FreeDict dictionary ver. 1.9-fd1 : [ freedict:eng-deu ]
regular expression /ɹˈɛɡjʊləɹ ɛkspɹˈɛʃən/ (RegExp /ɹˈɛdʒ ˈɛksp/, ) (Regex /ɹɪdʒˈɛks/)
regulärer Ausdruck
see: regular, regular function
From English-suomi FreeDict+WikDict dictionary ver. 2023.05.29 : [ freedict:eng-fin ]
regular expression /ɹˈɛɡjʊləɹ ɛkspɹˈɛʃən/
säännöllinen lauseke
computing: a concise description of a pattern to be matched
From English-日本語 (にほんご) FreeDict+WikDict dictionary ver. 2023.05.29 : [ freedict:eng-jpn ]
regular expression /ɹˈɛɡjʊləɹ ɛkspɹˈɛʃən/
正規表現
computing: a concise description of a pattern to be matched
From English-Romanian FreeDict Dictionary ver. 0.6.3 : [ freedict:eng-rom ]
regular expression /ɹˈɛɡjʊləɹ ɛkspɹˈɛʃən/
expresie obișnuită
From English-Svenska FreeDict+WikDict dictionary ver. 2023.05.29 : [ freedict:eng-swe ]
regular expression /ɹˈɛɡjʊləɹ ɛkspɹˈɛʃən/
reguljärt uttryck
computing: a concise description of a pattern to be matched
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