help using PEAR mime_type for on disk files

[epu]

Hey dude(tte)s,

I'm trying to print the mime types of a bunch of file on disk and stuff them into a database. The database is supposed to contain the path to the file, a mime type, and some other info, but the mime_types are often missing.

I've opened a connection to my db and I can print out the name of the file and see if it exists with the following

 
<?
        #do something
        $sql  = 'select id, diskfile, file_type from mantis_bug_file_table where file_type = ?';
        #$data = array('text/plain');
        $data = array('');
        $res =& $db->query($sql, $data);
        // Always check that result is not an error
        if (DB::isError($res)) {
            die($res->getMessage());
        }
        while ($row =& $res->fetchRow(DB_FETCHMODE_ASSOC)) {
                echo "<p>" . $row['diskfile'] . "</p>";
                $mt = MIME_Type::autodetect($row['diskfile'] );
                if (PEAR::isError($mt)){
                        #die($mt->getMessage());
                        echo $mt->getMessage();
                } else {
                #       echo "<p>" . MIME_Type::parse($mt) . "</p>";
                }
        }
?>

but with this code, I get a pear error Can't find file command "file".

Mime_Type depends on System_command; I think for some reason it can't run the unix command /usr/bin/file. /usr/bin is in apache's path.

Is my syntax wrong, or are there permissions to check? I'm still pretty green to php.