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phpregexpreg-replaceregex-groupregex-greedy

How to get part of a URL?

How can I remove all the parts from url except base url and first part. There is no certainty in number of parts. Base url is variable. I tried some regex but in vain. 

$url =  http://www.example.com/part1/part2/part3/part4;
base_url = parse_url($url, PHP_URL_HOST); // Outputs www.example.com

$desired_output = http://www.example.com/part1;
Solution

  • Here we can use a preg_replace, with a simple expression, maybe similar to:

    (.+\.com\/.+?\/).+

    where we are capturing our desired output using this capturing group:

    (.+\.com\/.+?\/)

    and then we swipe to the end of string and replace it with $1.

    Test

    $re = '/(.+\.com\/.+?\/).+/m';
$str = 'http://www.example.com/part1/part2/part3/part4';
$subst = '$1';

$result = preg_replace($re, $subst, $str);

echo $result;

    DEMO

    RegEx Circuit

    jex.im visualizes regular expressions:

    enter image description here

    For all domains .com or not, we might be able to solve it with this expression:

    (.+\..+?\/.+?\/).+

    Test

    $re = '/(.+\..+?\/.+?\/).+/m';
$str = 'http://www.example.com/part1/part2/part3/part4';
$subst = '$1';

$result = preg_replace($re, $subst, $str);

echo $result;

    Demo