Search results
Results From The WOW.Com Content Network
A regular expression (shortened as regex or regexp), [1] ... However, they are often written with slashes as delimiters, as in /re/ for the regex re.
The slash is also used as the default regular expression delimiter, so to be used literally in the expression, it must be escaped with a backslash \, leading to frequent escaped slashes represented as \/. If doubled, as in URLs, this yields \/\/ for an escaped //.
Metacharacters are interpreted unless quoted by a backslash, double quotes, or square brackets. See the section on regex. The obvious example is, you must quote any slash in your pattern so it won't be interpreted as the closing slash delimiter, using \/ instead of / to match a literal slash. A regexp interprets all metacharacters.
The regular expression (i.e. pattern) to be searched is placed after the first delimiting symbol (slash here) and the replacement follows the second symbol. Slash ( / ) is the conventional symbol, originating in the character for "search" in ed, but any other could be used to make syntax more readable if it does not occur in the pattern or ...
The slash is a slanting line punctuation mark /.It is also known as a stroke, a solidus, a forward slash and several other historical or technical names.Once used as the equivalent of the modern period and comma, the slash is now used to represent division and fractions, as a date separator, or to connect alternative terms.
These find wikitext without resorting to the regex searches this template does with insource:/slash-delimited arguments/, (which is a common syntax for regex searches). See § About CirrusSearch below for a better understanding of when this template is not needed.
Multiple quoting is particularly useful with regular expressions that contain usual delimiters such as quotes, as this avoids needing to escape them. An early example is sed, where in the substitution command s/regex/replacement/ the default slash / delimiters can be replaced by another character, as in s,regex,replacement,.
Since UNCs start with two backslashes, and the backslash is also used for string escaping and in regular expressions, this can result in extreme cases of leaning toothpick syndrome: an escaped string for a regular expression matching a UNC begins with 8 backslashes – \\\\\ – because the string and regular expression both require escaping.