how to find out if csv file fields are tab delimited or comma delimited

Question

how to find out if csv file fields are tab delimited or comma delimited. I need php validation for this. Can anyone plz help. Thanks in advance.

Answer 1

Thanks for all your inputs, I made mine using your tricks : preg_split, fgetcsv, loop, etc.

But I implemented something that was surprisingly not here, the use of fgets instead of reading the whole file, way better if the file is heavy!

Here's the code :

ini_set("auto_detect_line_endings", true);
function guessCsvDelimiter($filePath, $limitLines = 5) {
    if (!is_readable($filePath) || !is_file($filePath)) {
        return false;
    }

    $delimiters = array(
        'tab'       => "\t",
        'comma'     => ",",
        'semicolon' => ";"
    );

    $fp = fopen($filePath, 'r', false);
    $lineResults = array(
        'tab'       => array(),
        'comma'     => array(),
        'semicolon' => array()
    );

    $lineIndex = 0;
    while (!feof($fp)) {
        $line = fgets($fp);

        foreach ($delimiters as $key=>$delimiter) {
            $lineResults[$key][$lineIndex] = count (fgetcsv($fp, 1024, $delimiter)) - 1;
        }

        $lineIndex++;
        if ($lineIndex > $limitLines) break;
    }
    fclose($fp);

    // Calculating average
    foreach ($lineResults as $key=>$entry) {
        $lineResults[$key] = array_sum($entry)/count($entry);
    }

    arsort($lineResults);
    reset($lineResults);
    return ($lineResults[0] !== $lineResults[1]) ? $delimiters[key($lineResults)] : $delimiters['comma'];
}