how to remove a string having special characters from a file using php

Question

I have this file.txt file

domain.com
domain2.com
domain3.com
@*.domain6.com
domain4.com
domain5.com

and I need to remove

@*.domain6.com

using php , I am using this code

$file="file.txt";
file_put_contents($file, preg_replace("/^\@\*\.domain6\.com$/","",file_get_contents($file)));

but it does not work , anyone can explain me why it does not work and how to remove this row ?

Answer 1

You need to use

$file="file.txt";
$rx = '/^\h*@\*\.domain6\.com\h*$/mu';
file_put_contents($file, preg_replace($rx,"",file_get_contents($file)));

Details:

• mu - m makes ^ match start of any line and $ end of any line
• ^ - start of a line
• \h* - any zero or more horizontal whitespaces
• @\*\.domain6\.com - @*.domain6.com string
• \h* - any zero or more horizontal whitespaces
• $ - end of string.

See this regex demo.

NOTE: If you have trouble with escaping special chars, in PHP, you can use

$rx = '/^\h*\Q@*.domain6.com\E\h*$/mu';

See this regex demo. All chars between \Q and \E are treated as literal chars.