cronolog is a simple filter program that reads log file entries from standard input and writes each entry to the output file specified by a filename template and the current date and time. When the expanded filename changes, the current file is closed and a new one opened. cronolog is intended to be used in conjunction with a Web server, such as Apache, to split the access log into daily or monthly logs. For example the Apache configuration directives:
TransferLog "|/usr/sbin/cronolog /web/logs/%Y/%m/%d/access.log"
ErrorLog "|/usr/sbin/cronolog /web/logs/%Y/%m/%d/errors.log"
would instruct Apache to pipe its access and error log messages into separate copies of cronolog, which would create new log files each day in a directory hierarchy structured by date, i.e. on 31 December 2002 messages would be written to
after midnight the files