Remove all lines starting with a specific character

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Hello,

I have a project that uses file_get_contents(); on an external page and would like to know how I can remove for example all lines starting with //.

The external page contains Javascript comments and I haven’t found anything that can only remove comments within the tag.

Example of external page code;

<!DOCTYPE html>
<html>
<body>
<script>
[...]
// Alerta
alert('Olá!');
[...]
</script>
</body>
</html>

Code I tried to use to remove comments;

$html = explode(PHP_EOL, file_get_contents('https://example.com/'));
foreach($html as $linha) {
    if(substr($linha, 0, 2) !== '//' && mb_substr($linha, 0, 2) !== '//') {
        $linhas[] = trim($linha);
    }
}
$html = implode(PHP_EOL, $linhas);
echo $html;

When I ran the script by the browser to see if you removed the comment or not, unfortunately I still got the comment.

I’m using XAMPP in the version 5.6.35.

php

  • It would be important to explain the "I didn’t succeed" better, and how you tested the output. Also, it does not make much sense to use substr E mb_substr in the test, mainly because the characters are not multibyte. I still think it would be good to make a trim in the string, if you want to delete comments that are not in the first position

  • I used substr along with mb_substr just to make sure there was no mistake, but it didn’t turn out like I thought haha.

  • Try to print_r each line (without the '/' test) to make sure the text is coming as you imagine, and the explode is happening in the right place.

  • I don’t think PHP_EOL is the best criterion in the explode, because it may be CRLF on your platform, but only CR or LF at the origin. I would probably prefer explode( chr(10), file_get_contents ...., or explode( "\n", file_get....

1 answer

0

You can use regular expressions to solve this problem. In my regex pattern I am looking for lines that start with "/" followed by another / . Finally I deny the lines that match this pattern.

pattern : "/^///" 

<?php 

 $html = explode(PHP_EOL, file_get_contents('./teste.html'));
   foreach($html as $linha) {
    if(!preg_match("/^\/\//", $linha)) {
     $linhas[] = trim($linha);
    }
  }
  $html = implode(PHP_EOL, $linhas);
  echo $html;
?>

Example HTML file.

LINHA 1 <br>
LINHA 2 <br>
LINHA 3 <br>
//NAO LEIA <br>
LINHA 4 <br>

Exit:

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