PHP Str_replace在大字符串上不起作用

Question

I am using str_replace to format a string with a relatively large (i think) number of characters but it doesnt process the string. below is my string and the code im using

$formlink = str_replace('&stepvars='.$_GET['stepvars'],'',$link);

The string is 1004 characters long

?content=com_motor&folder=same&file=motor_form&step=one&stepvars=VzNOMGNERmRkR2wwYkdVOVBsTmxiR1ZqZENCVWFYUnNaU3h3Y205d2IzTmxjbDl6ZFhKdVlXMWxQVDVOZFdOb2FYSnBMRzkwYUdWeVgyNWhiV1Z6UFQ1VVpYTjBJRTkwYUdWMExHOWpZM1Z3WVhScGIyNWZjSEp2Wm1WemMybHZiajArVjJWaUlFUmxjMmxuYm1WeUxHUmhlVDArTVRjc2JXOXVkR2c5UGs5amRHOWlaWElzZVdWaGNqMCtNakF3TWl4d2FXNWZibTg5UGpFeU16UTFOaXhwWkY5dmNsOXdZWE56Y0c5eWRGOXViejArTmpVME16SXhMR1J5YVhabGNsOXNhV05sYm5ObFgyNXZQVDQyTXpJMU5ERXNlV1ZoY2w5bWFYSnpkRjlrY21sMmFXNW5YMnhwWTJWdWMyVmZhWE56ZFdWa1BUNHlNREEwTEc1MWJXSmxjbDl2Wmw5NVpXRnljMTlrY21sMmFXNW5YMlY0Y0dWeWFXVnVZMlU5UGpVc1pXMWhhV3hmWVdSa2NtVnpjejArYzI1bmRXMXZRR2R0WVdsc0xtTnZiU3h0YjJKcGJHVmZiblZ0WW1WeVBUNHdOelF4TlRJMk15eHdYMjlmWW05NFBUNHhNalUwZEdWemRDeHdiM04wWVd4ZlkyOWtaVDArTVRJMU5EYzRMSFJ2ZDI0OVBrNWhhWEp2WW1rc1pHOWZlVzkxWDE5aGJtUnZjbDloYm5sZmIzUm9aWEpmY0dWeWMyOXVjMTkzYUc5ZmRHOWZlVzkxY2w5cmJtOTNiR1ZrWjJWZmQybHNiRjlrY21sMlpWOTBhR1ZmWTJGeVgxOXpYMTlmYzNWbVptVnlYMlp5YjIxZlpHVm1aV04wYVhabFgzWnBjMmx2Ymw5dmNsOW9aV0Z5YVc1blgyOXlYMkZ1ZVY5d2FIbHphV05oYkY5cGJtWnBjbTFwZEhsZmFXNWpiSFZrYVc1blgyWnBkSE05UGpBc1czeHpkSEF4WFE9PQ%3D%3D&msgvalid=Now_enter_your_vehicle_details

Please assist me as to where Im going wrong.

Thanks

Answer 1

What's probably happening is that your URL has escaped characters in it (%3D%3D) and your $_GET is the unescaped characters so they don't match. str_replace can work on very large strings without a problem.

If you want to get rid of that value, just do this:

$query_params = $_GET;
unset($query_params['stepvars']);
$new_link = http_build_query($query_params);

That will work even if the param is the first one (?stepvars=...)

Answer 2

In the grand scheme of things, that string is not very large and that is unlikely to be the source of the problem here.

What is far more likely is that the problem is caused by the %3D%3D at the end of the string, which $_GET will translate into == which will cause the string not to match if %3D%3D is what you're looking for.