Please submit a single PHP source file.

1. You need to open a file orders.txt for writing. Modify the following code, specifically the two placeholders, to accomplish your goal.

$fp = ___("$document_root/../orders/orders.txt", '___');

2. Use the PHP fwrite function to write a string stored in $outputstring (you choose the content of the string) to the file pointed to by $fp.

3. Use a PHP File IO function to close the file. Then reopen the file for reading.

4. You need to use a PHP while loop to read from a file until the end of the file is reached. Modify the following code to accomplish your goal. As before, you will need to find the correct File IO API to accomplish this

while (!___($fp))

5. Use PHP to echo the size of the file orders.txt.