classes/phing/system/io/FileSystem.php
public function chgrp($pathname, $group)
    {
        if (false === @chgrp($pathname, $group)) { // FAILED.
            $msg = "FileSystem::chgrp() FAILED. Cannot chown $pathname. Group $group." . (isset($php_errormsg) ? ' ' . $php_errormsg : "");
            throw new IOException($msg);
        }
    }
public function chgrp($pathname, $group)
    {
        if (false === @chgrp($pathname, $group)) { // FAILED.
            $msg = "FileSystem::chgrp() FAILED. Cannot chown $pathname. Group $group." . (isset($php_errormsg) ? ' ' . $php_errormsg : "");
            throw new IOException($msg);
        }
    }
public function chgrp ( $ pathname , $ group ) { if ( false === @ chgrp ( $ pathname , $ group ) ) { // FAILED. $ msg = "FileSystem::chgrp() FAILED. Cannot chown $pathname. Group $group." . ( isset ( $ php_errormsg ) ? ' ' . $ php_errormsg : "" ) ; throw new IOException ( $ msg ) ; } }
Change the group on a file or directory.

@param string $pathname Path and name of file or directory.
@param string $group The group of the file or directory. See http://us.php.net/chgrp

@return void
@throws IOException if operation failed.
Change the group on a file or directory .