问下PHP里面怎么改名？

Question

$path=http://AAA/AAA.jpg想把上头的名字改为$path=http://AAA/AAA_100x100.jpg请问用php的话，要怎么写这行代码啊？其中http://AAA/AAA.jpg是个变量得出的结果~

Answer 1

echo $path= substr($path,0,(strlen($path)-4)).'_100x100.jpg';

或者
echo $path= substr($path,0,(strlen($path)-4)).'_100x100'.substr($path,-4);

Answer 2

$path = preg_replace('/AAA.jpg/',  'AAA_100x100.jpg', $path) 已测试 可用