PHP preg_replace all text changing - php

Question

I want to make some changes to the html but I have to follow certain rules.
I have a source code like this;
A beautiful sentence http://www.google.com/test, You can reach here http://www.google.com/test-mi or http://www.google.com/test/aliveli
I need to convert this into the following;
A beautiful sentence http://test.google.com/, You can reach here http://www.google.com/test-mi or http://test.google.com/aliveli
I tried using str_replace;
$html = str_replace('://www.google.com/test','://test.google.com');
When I use it like this, I get an incorrect result like;
A beautiful sentence http://test.google.com/, You can reach here http://test.google.com/-mi or http://test.google.com/aliveli
Wrong replace: http://test.google.com/-mi
How can I do this with preg_replace?

Answer 1

With regex you can use a word boundary and a lookahead to prevent replacing at -
$pattern = '~://www\.google\.com/test\b(?!-)~';
$html = preg_replace($pattern, "://test.google.com", $html);
Here is a regex demo at regex101 and a php demo at eval.in
Be aware, that you need to escape certain characters by a backslash from it's special meaning to match them literally when using regex.

Answer 2

It seems you're replacing the subdirectory test to subdomain. Your case seems to be too complicated. But I've given my best to apply some logic which may be reliable or may not be unless your string stays with the same structure. But you can give a try with this code:
$html = "A beautiful sentence http://www.google.com/test, You can reach here http://www.google.com/test-mi or http://www.google.com/test/aliveli";
function set_subdomain_string($html, $subdomain_word) {
$html = explode(' ', $html);
foreach($html as &$value) {
$parse_html = parse_url($value);
if(count($parse_html) > 1) {
$path = preg_replace('/[^0-9a-zA-Z\/-_]/', '', $parse_html['path']);
preg_match('/[^0-9a-zA-Z\/-_]/', $parse_html['path'], $match);
if(preg_match_all('/(test$|test\/)/', $path)) {
$path = preg_replace('/(test$|test\/)/', '', $path);
$host = preg_replace('/www/', 'test', $parse_html['host']);
$parse_html['host'] = $host;
if(!empty($match)) {
$parse_html['path'] = $path . $match[0];
} else {
$parse_html['path'] = $path;
}
unset($parse_html['scheme']);
$url_string = "http://" . implode('', $parse_html);
$value = $url_string;
}
}
unset($value);
}
$html = implode(' ', $html);
return $html;
}
echo "<p>{$html}</p>";
$modified_html = set_subdomain_string($html, 'test');
echo "<p>{$modified_html}</p>";
Hope it helps.

Answer 3

If the sentence is the only case in your problem you don't need to start struggling with preg_replace.
Just change your str_replace() functioin call to the following(with the ',' at the end of search string section):
$html = str_replace('://www.google.com/test,','://test.google.com/,');
This matches the first occurance of desired search parameter, and for the last one in your target sentence, add this(Note the '/' at the end):
$html = str_replace('://www.google.com/test/','://test.google.com/');
update:
Use these two:
$targetStr = preg_replace("/:\/\/www.google.com\/test[\s\/]/", "://test.google.com/", $targetStr);
It will match against all but the ones with comma at the end. For those, use you sould use the following:
$targetStr = preg_replace("/:\/\/www.google.com\/test,/", "://test.google.com/,", $targetStr);