Question

I have a text file I want to read, but exclude lines that contain certain character at the start (hence “@”, or whatever one defined later):

@ I don't want this line to be read
This line should be read;
"This one" should be read, too;
'Also this one' should be read;
...etc
@ But this one should be ignored;

With below code I can explode those that ends with a semicolon (“;”), but the last line should not, because it begins with a “@”.

$contents = file_get_contents($the_path);
$result = array_map('trim', explode(";", $contents));

Any hint to achieve this? Thanks

UPDATE the codes:

// http://stackoverflow.com/questions/10257244/php-preg-match-all-read-content-and-exclude-unwanted/10257319
  $results = array();
  $matches = array();
  $the_path = '/path/to/file.txt';
  if (is_file($the_path)) {
    $contents = file_get_contents($the_path);
    if ($contents) {
      // ! array warning
      // $contents = array_map('rtrim', $contents);
      // $matches = preg_grep('#^@#', $contents, PREG_GREP_INVERT);
      $matches = preg_split("/[\r\n]/", preg_replace("/@.*?[\r\n]/", "", $contents), NULL, PREG_SPLIT_NO_EMPTY);

      if ($matches) {
        foreach ($matches as $key => $val) {
          $results[$key] = $val;
        }
      }
    }
  }
  // Attempt to remove the first 0 key, and start from 1, because 0|value0 is considered NULL
  $results = array_combine(range(1, count($results)), array_values($results));

  return !empty($results) ? $results : array();

UPDATE 2, works properly via DCoder:

  $matches = array();
  if ($contents = file($the_path)) {
      $contents = array_map('rtrim', $contents);
      $keyword = '@';
      // Still output @line
      // $matches = preg_grep('#^@#', $contents, PREG_GREP_INVERT); 
      // Ok, thanks to http://php.net/manual/de/function.preg-grep.php#85503
      $matches = preg_grep("/{$keyword}/i", $contents, PREG_GREP_INVERT);         

      // $matches = preg_split("/[\r\n]/", preg_replace("/@.*?[\r\n]/", "", $contents), NULL, PREG_SPLIT_NO_EMPTY);
      // dsm($matches);
      if ($matches) {
        foreach ($matches as $key => $match) {
         $results[$key] = $match;
        }
      }
  }


  // $results = array_combine(range(1, count($results)), array_values($results));
  return $results;

Answer 1

// get the contents of the file as an array of lines
$contents = file($the_path);
if($contents === false) {
    throw new Exception("Failed to open file {$the_path}");
}
// drop ending newlines
$contents = array_map('rtrim', $contents);

// find all lines except those starting with @
$matched = preg_grep('#^@#', $contents, PREG_GREP_INVERT);