Log errors in a file

How do I log all process crashes into a file instead of a tty ? I've read in the documentation that there are some s开发者_开发技巧tandard Erlang modules that can do it (SASL, error_logger), but unfortunately haven't found any clean examples.

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Start your erl node with

erl -boot start_sasl -sasl sasl_error_logger \{file,\"path/to/logfile.log\"\}