<?php
//test.php
@unlink("/tmp/abc.php");
var_dump(@include_once("/tmp/abc.php"));
swritefile("/tmp/abc.php","<?php echo 123;");
var_dump(file_exists("/tmp/abc.php"));
var_dump(include_once("/tmp/abc.php"));
function swritefile($filename, $writetext, $openmod="w")
{
if (@$fp = fopen($filename, $openmod)) {
flock($fp, 2);
fwrite($fp, $writetext);
fclose($fp);
return true;
}
}
run it three times for the above code:
- access the test.php, output as follows
bool(false) bool(true) 123int(1)- change the user to which the generated file belongs
chown vaxili:vaxili / tmp/abc.php. Then visit the test.php output as follows
123int(1) bool(true) bool(true)- Delete the generated file
rm / tmp/abc.php, and access the test.php, output as follows:
bool(false) bool(true) bool(true)