Karl Jones at 22:10, 26 August 2016

2016-08-26T22:10:50Z

Karl Jones: Created page with "In computing, a '''metacharacter''' is a character that has a special meaning (instead of a literal meaning) to a computer program, such as a..."

2016-08-26T22:06:43Z

Created page with "In computing, a '''metacharacter''' is a character that has a special meaning (instead of a literal meaning) to a computer program, such as a..."

New page

In [[computing]], a '''metacharacter''' is a [[Character (computing)|character]] that has a special meaning (instead of a literal meaning) to a [[computer program]], such as a shell interpreter or a regular expression engine.

== Description ==

In POSIX extended regular expressions, there are 14 metacharacters that must be preceded by a backslash "\" in order to drop their special meaning and be treated literally inside an expression: the open/close square brackets, "[" and "]"; the backslash "\"; the caret "^"; the dollar sign "$"; the period or dot "."; the vertical bar or pipe symbol "|"; the question mark "?"; the asterisk "*"; the plus-sign "+"; open/close curly braces, "{" and "}"; and open/close parenthesis, "(" and ")".

If you want to use any of these characters as a literal in a regex, you need to escape them with a backslash. For example, to match the arithmetic expression "(1+1)*3=6" with a regex, then the correct regex is "$1\+1$\*3=6". Otherwise, the parenthesis, plus-sign, and asterisk will have a special meaning.

== See also ==

* [[Delimiter]]
* [[Markup language]]

== External links ==

* [https://en.wikipedia.org/wiki/Metacharacter Metacharacter] @ Wikipedia

[[Category:Computer science]]

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-In [[computing]], a '''metacharacter''' is a [[Character (computing)|character]] that has a special meaning (instead of a literal meaning) to a [[computer program]], such as a shell interpreter or a regular expression engine.
+In [[computing]], a '''metacharacter''' is a [[Character (computing)|character]] that has a special meaning (instead of a literal meaning) to a [[computer program]], such as a [[Shell (computing)|shell interpreter]] or a [[regular expression]] engine.
 == Description ==
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 * [[Delimiter]]
 * [[Markup language]]
 == External links ==
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 [[Category:Computer science]]

Metacharacter - Revision history

Karl Jones at 22:10, 26 August 2016

Karl Jones: Created page with "In computing, a '''metacharacter''' is a character that has a special meaning (instead of a literal meaning) to a computer program, such as a..."