simple fopen question

[Anon]

In my understanding, when you use fopen to open a file in r+ the pointer goes at the beginning of the file. So if the original file simply containts the text "message1" and i use the code

$fp= fopen("filename.txt", "r+");
fwrite($fp,"message2\r\n");
fclose();

the file contents should be
message2
message1

as far as i know. i must be missing something.

[[deleted]]

Indeed you are.
It is not possible to insert new data into a file, you can only overwrite and append.

http://www.hvt-automation.nl/yapf/files/textfile_prepend.php