/**
* Find the MIME type of a file using the XDG recommended checking order.
*
* This first checks the filename, then uses file contents
* if the name doesn't give an unambiguous MIME type.
* It can also handle special filesystem objects like directories and sockets.
*
* @param string $path file path to examine (need not exist)
* @param bool $followLinks whether to follow symlinks
*
* @return MimeType
*/
public function guessType($path, $followLinks = true)
{
/*
* The RECOMMENDED order to perform the checks is:
*
* - If a MIME type is provided explicitly
* (eg, by a ContentType HTTP header, a MIME email attachment, an extended attribute or some other means)
* then that should be used instead of guessing.
*
* - Otherwise, start by doing a glob match of the filename.
* If one or more glob matches, and all the matching globs result in the same mimetype,
* use that mimetype as the result.
*
* - If the glob matching fails or results in multiple conflicting mimetypes,
* read the contents of the file and do magic sniffing on it.
* If no magic rule matches the data (or if the content is not available),
* use the default type of application/octet-stream for binary data, or text/plain for textual data.
* If there was no glob match, use the magic match as the result.
*
* - Note: Checking the first 32 bytes of the file for ASCII control characters
* is a good way to guess whether a file is binary or text,
* but note that files with high-bit-set characters should still be treated as text
* since these can appear in UTF-8 text, unlike control characters.
*
* - If any of the mimetypes resulting from a glob match is equal to
* or a subclass of the result from the magic sniffing, use this as the result.
* This allows us for example to distinguish text files called "foo.doc"
* from MS-Word files with the same name, as the magic match for the MS-Word file
* would be application/x-ole-storage which the MS-Word type inherits.
*
* - Otherwise use the result of the glob match that has the highest weight.
*/
if (!file_exists($path)) {
return $this->guessTypeByFileName($path);
}
$stat = $followLinks ? stat($path) : lstat($path);
if (($stat['mode'] & self::STAT_IFMT) !== self::STAT_IFREG) {
// special filesystem objects
return $this->guessTypeByStat($stat['mode']);
}
/** @var Glob[] $globs */
$globs = $this->globsDb->match($path, false);
usort($globs, function ($a, $b) {
return $b->weight - $a->weight;
});
$possible = null;
if ($globs) {
$maxWeight = $globs[0]->weight;
$i = 1;
foreach (array_slice($globs, 1) as $glob) {
if ($glob->weight < $maxWeight) {
break;
}
$i++;
}
$globs = array_slice($globs, 0, $i);
if (count($globs) === 1) {
return $globs[0]->type;
}
$possible = $globs;
}
$type = null;
try {
$type = $this->magicDb->match($path, 100, 0, $possible);
} catch (\Exception $e) {
}
if ($type) {
return MimeType::create($type);
} elseif ($globs) {
return $globs[0]->type;
} elseif ($stat['mode'] & self::STAT_IMODE & 0111) {
return MimeType::defaultExecutable();
} elseif ($this->looksLikeTextFile($path)) {
return MimeType::defaultText();
}
return MimeType::unknown();
}
