Search results
Results From The WOW.Com Content Network
A metacharacter is a character that has a special meaning to a computer program, such as a shell interpreter or a regular expression (regex) engine.. In POSIX extended regular expressions, there are 14 metacharacters that must be escaped (preceded by a backslash (\)) in order to drop their special meaning and be treated literally inside an expression: opening and closing square brackets ([and ...
A regular expression (shortened as regex or regexp ), [1] sometimes referred to as rational expression, [2] [3] is a sequence of characters that specifies a match pattern in text. Usually such patterns are used by string-searching algorithms for "find" or "find and replace" operations on strings, or for input validation.
A regex search scans the text of each page on Wikipedia in real time, character by character, to find pages that match a specific sequence or pattern of characters. Unlike keyword searching, regex searching is by default case-sensitive, does not ignore punctuation, and operates directly on the page source (MediaWiki markup) rather than on the ...
String literal. A string literal or anonymous string is a literal for a string value in the source code of a computer program. Modern programming languages commonly use a quoted sequence of characters, formally "bracketed delimiters", as in , where is a string literal with value. Methods such as escape sequences can be used to avoid the problem ...
In the C programming language, an escape sequence is specially delimited text in a character or string literal that represents one or more other characters to the compiler. It allows a programmer to specify characters that are otherwise difficult or impossible to specify in a literal. An escape sequence starts with a backslash ( \) called the ...
In many popular fonts the Unicode "superscript" and "subscript" characters are actually numerator and denominator glyphs. Unicode has subscripted and superscripted versions of a number of characters including a full set of Arabic numerals. [1] These characters allow any polynomial, chemical and certain other equations to be represented in plain ...
Perl Compatible Regular Expressions ( PCRE) is a library written in C, which implements a regular expression engine, inspired by the capabilities of the Perl programming language. Philip Hazel started writing PCRE in summer 1997. [3] PCRE's syntax is much more powerful and flexible than either of the POSIX regular expression flavors (BRE, ERE ...
Escape character. In computing and telecommunication, an escape character is a character that invokes an alternative interpretation on the following characters in a character sequence. An escape character is a particular case of metacharacters. Generally, the judgement of whether something is an escape character or not depends on the context.