TOPIC 11.3.1
Differences in Appending Files

The Macintosh CodeWarrior compiler does not support the use of ios::app alone as a valid stream operation. Consult CodeWarrior's documentation if you are using the CodeWarrior compiler.

When opening a file for appending, use both the ios::out and ios::app operation modes. For example, instead of

outfile.open("NAME_AGE.DAT", ios::app);

use

outfile.open("NAME_AGE.DAT", ios::out | ios::app);