/**
* Changes file group.
* Use of $flags might cause an exception based on the operation system.
*
* @param int|string $group Group id or groupname
* @param int $flags Fs::% options as binary set
* @throws Fs_Exception or ExecException if chown fails.
*/
public function chgrp($group, $flags = 0)
{
if (!$this->exists($flags)) {
throw new Fs_Exception("Unable to change group of '{$this->_path}' to '{$group}': " . ($this instanceof Fs_Symlink && is_link($this->_path) ? "Unable to dereference symlink" : "File does not exist"));
}
if ($flags == 0) {
if (!@chgrp($this->_path, $group)) {
throw new Fs_Exception("Failed to change group of '{$this->_path}' to '{$group}'", error_get_last());
}
} else {
Fs::bin('chgrp')->exec($group, $this->_path, $flags & Fs::RECURSIVE ? '-r' : null, $flags & Fs::NO_DEREFERENCE ? '--no-dereference' : null, $flags & Fs::ALWAYS_FOLLOW ? '-L' : null);
}
$this->clearStatCache();
}