How Can I Reliably Remove Multiple UTF-8 BOM Sequences from a String in PHP?

Eliminating Multiple UTF-8 BOM Sequences

When reading template files from the filesystem using PHP5 (cgi), issues with raw HTML output can arise. This is often attributed to the presence of UTF-8 BOM (Byte Order Mark) sequences.

A common approach to address this is to manually remove the BOM sequence if it exists. However, this method can be ineffective if multiple BOM sequences are present within the file.

To effectively remove all UTF-8 BOM sequences, consider using a more comprehensive approach:

// Function to Remove UTF8 BOM
function remove_utf8_bom($text)
{
    $bom = pack('H*','EFBBBF');
    $text = preg_replace("/^$bom/", '', $text);
    return $text;
}

This function employs a regular expression to match and remove any UTF-8 BOM character sequence encountered at the beginning of the string (/^$bom/). By ensuring all BOM sequences are removed even in instances where multiple occurrences exist, this function provides a more robust solution for sanitizing your template files.

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