PHP golf

Minified

<?php $b=99;$d=" bottles of beer";$c="$d on the wall";$f="file";do{echo "$b$c, $b$d.\n";if(!--$b){echo $f('http://is.gd/sKW90b')[0];$b=99;}else echo $f('http://is.gd/2m5PYo')[0];echo ", $b$c.\n\n";}while($b<99);

Readable

<?php
$b=99;
$d=" bottles of beer";
$c="$d on the wall";
$f="file";
do{
    echo "$b$c, $b$d.\n";
    if(!--$b){
        echo $f('http://is.gd/sKW90b')[0];$b=99;
    }
    else echo $f('http://is.gd/2m5PYo')[0];
    echo ", $b$c.\n\n";
}while($b<99);