为什么我不能用PHP写文件？

Question

Hi i have a client connecting to a socket server in php.

I want to empty a particular file after connecting to the server, however, the codes is not giving me any error but it is not writing to the file?

<?php 
set_time_limit(0);

//parameters to connect to server
$ip = "127.0.0.1";
$port = "1245";
$data = "";

$socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
$result = socket_connect($socket, $ip, $port);

$myFile = "test.txt";
$fh = fopen($myFile, 'w') or die("can't open file");
fwrite($fh, ""); 

while (true)
{
        $data = "some value here"

        socket_write($socket, $data, strlen($data));

        $line =@socket_read($socket,2048, PHP_NORMAL_READ);
        if($line != "")
        {
                echo $line."
";
        }   

}
socket_close($socket);
?>

Answer 1

I'd use an absolute path $myFile = "/tmp/test.txt"; to make sure I knew where the file was to be written. Right now with just text.txt it could be written in a variety of places but most likely where the web servers binary is located.

If you'd rather not use an absolute path you can use http://php.net/manual/en/function.getcwd.php and http://www.php.net/manual/en/function.chdir.php to control the current working directory.