Php program causes the disk space to soar

The php program causes the disk space usage to soar. this program instantly causes the cpu and memory usage of my computer to soar. When I look at the space used by the hard disk, it is also increasing. now I am at a loss, what is the hard disk space that cannot be found? The hard disk space cannot be restored. I am a beginner in php. hope you can give me more advice? Asking for help !!!

$ Filename = "/home/wanbo/test/file/test.txt ";
If (file_exists ($ filename) echo "the file is there .";
Else echo "there isn' t such a file ";
$ Myfile = fopen ($ filename, "a + ");
Fwrite ($ myfile, "hello, world ");
While (! Feof ($ myfile ))
{
$ Mychar = fgetc ($ myfile );
Echo $ mychar;
}
Fclose ($ myfile );
?>

The above is the content that causes the hard drive to use space to soar. For more information, see php Chinese network (www.php1.cn )!