Should log file streams be opened/closed on each write or kept open during a desktop application's lifetime?

Question

Should log classes open/close a log file stream on each write to the log file or should it keep the log file stream open throughout the application\'s lifetime until all log

Answer 1

For performance, keep open. For safety, flush often.

This will mean that the run-time library will not try to buffer writes until it has lots of data -- you may crash before that's written!