I'm trying to write regex rules for preg_replace and need to append something to a sub string that contains at least one | and ends in line break.

$str = '"as das dasd", "asrydasd|artysdad|aksda'; // no trailing "

$find = '/^\"*\|*\n$/s';

$replace = $1.'"';

$result = preg_replace($find, $replace, $str);

CodePudding user response：

In your pattern you use an anchor to assert the start of the string. There is also no newline at the end of the string present, and no capture group $1 that you refer to in the replacement.

Your pattern curently matches optional double quotes, then optional pipe chars, a newline and then asserts the end of the string. That can also match an empty string followed by a newline.

If you only want to make sure that the string starts with a double quote and contains at least a single pipe char:

^"[^|\r\n]*\|.*\n$

Regex demo

Looking at the comment in the code, if you want to match a pipe between an inclosed double quote till the end of the string:

"[^"|\r\n]*\|[^"\r\n]*$

Regex demo

Replace with the whole match $0"