public function encodeQ($str, $position = 'text')
{
// There should not be any EOL in the string
$pattern = '';
$encoded = str_replace(["\r", "\n"], '', $str);
switch (strtolower($position)) {
case 'phrase':
// RFC 2047 section 5.3
$pattern = '^A-Za-z0-9!*+\\/ -';
break;
/** @noinspection PhpMissingBreakStatementInspection */
/** @noinspection PhpMissingBreakStatementInspection */
case 'comment':
// RFC 2047 section 5.2
$pattern = '\\(\\)"';
// intentional fall-through
// for this reason we build the $pattern without including delimiters and []
// intentional fall-through
// for this reason we build the $pattern without including delimiters and []
case 'text':
default:
// RFC 2047 section 5.1
// Replace every high ascii, control, =, ? and _ characters
$pattern = '\\000-\\011\\013\\014\\016-\\037\\075\\077\\137\\177-\\377' . $pattern;
break;
}
$matches = [];
if (preg_match_all("/[{$pattern}]/", $encoded, $matches)) {
// If the string contains an '=', make sure it's the first thing we replace
// so as to avoid double-encoding
$eqkey = array_search('=', $matches[0]);
if (false !== $eqkey) {
unset($matches[0][$eqkey]);
array_unshift($matches[0], '=');
}
foreach (array_unique($matches[0]) as $char) {
$encoded = str_replace($char, '=' . sprintf('%02X', ord($char)), $encoded);
}
}
// Replace every spaces to _ (more readable than =20)
return str_replace(' ', '_', $encoded);
}