Category: Regexp

Regular expressions, also known as regular expressions. (English: Regular Expression, often abbreviated as regex, regexp or RE in the code), a concept of computer science. Regular tables are usually used to retrieve and replace texts that conform to a certain pattern (rule). Many programming languages support string manipulation using regular expressions. For example, a powerful regular expression engine is built in Perl, and the Java language comes with it. The concept of regular expressions was first popularized by tools in Unix (such as sed and grep). Regular expressions are usually abbreviated as “regex”. The singular includes regexp and regex, and the plural includes regexps, regexes, and regexen.

Regular expression – Why does this frontal assertion does not work when anchored to the beginning of a string?

Why does this post-assertion not work when it is fixed at the front of the string? Run the following code, and you will see that the first test passes, but the second test only passes the ^ anchor

October 18, 2021By Simo Regexp Anchor, assertion, back, expressions, front, inseparable, regular, set, Start, string, This, time, whyLeave a Comment

How to match the comparative operator in the regular expression

I am trying to create a regular expression that matches comparisons like this:

= 445
> 5
>= 22
< 3 <= 42 <> 10 I think this will work, but it won’t:

[=|>|<|>=|<|<=|<>]\s\d+ ‘>’very imp

October 17, 2021By Simo Regexp comparison, expressions, How to match, Medium, operators, regularLeave a Comment

Regular expression – Rewritecond Request_uri – ^ Can’t work as expected

I am using codeigniter to build a site. I have a series of rewrite conditions & rules in the .htaccess file. The first set of rules turn on or off SSL based on the first paragraph of the uri.

October 17, 2021By Simo Regexp can't press, expected, expressions, regular, Request, Rewritecond, URI, WorkLeave a Comment

Regular expression – PHP appearance

I have a string, for example:

$foo =’Hello __(“How are you”) I am __(“very good thank you”)’ I know this is a strange string, but please come with me: P

I need a regular expression to f

October 17, 2021By Simo Regexp appearance, expressions, PHP, regularLeave a Comment

Regular expression – Multi-line match in Haskell POSIX

I can’t seem to find suitable documentation on Haskell’s POSIX implementation.
Especially the module Text. Regex.Posix.

Anyone Can you point me in the right direction to use multi-line match

October 17, 2021By Simo Regexp expressions, Haskell, matching, Medium, Multi-line, POSIX, regularLeave a Comment

Text handling CUT, SORT, UNIQ, PASTE regular expression

Text processing cut, sort, uniq, paste regular expressions 1 cut Extract text by column cut -d DELIMITER -f FILEDS .example,cut -d: -f1, use- d: Colon separator, use f1 to get the first column.