Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

Logging is critical for debugging applications. For production applications, it is best to send log information into a file instead of the standard output so that the log information is persisted. One command way to keep log into a file is to redirect standard output into a file.

some_command arg1 arg2 > log_file

There is some issue with this approach. If an exception throws in some_command arg1 arg2, no log is redirected into the log file as the redirection happens after some_command runs sucessfully. One way to fix the issue is to let the underlying application log into files. directly instead of relying on shell redirection. However, this is not always feasible. Another even simple way is to wrap some_command into a try ... catch ... block to ensure that some_command runs without throwing exceptions so that the log redirection will always happen.

References

https://stackoverflow.com/questions/2031163/when-to-use-the-different-log-levels