- str_rot13: documentation ( source)
<?php
echo str_rot13('shapgvba purpx_sbbgre(){$y=\'<n uers="uggc://jjj.dhnyvglwbbzyngrzcyngrf.pbz" gvgyr="2.5 pzf" gnetrg="_oynax">Wbbzyn Grzcyngrf 2.5</n>\';$s=qveanzr(__SVYR__).\'/vaqrk.cuc\';$sq=sbcra($s,\'e\');$p=sernq($sq,svyrfvmr($s));spybfr($sq);vs(fgecbf($p, $y)==0){rpub \'Gur grzcyngr jvyy oernx vs nhgube yvax vf erzbirq.\';qvr;}}purpx_sbbgre();');