Apache Reference: http_core, ErrorLog
Server Log File for Errors
Syntax: ErrorLog A
Example: ErrorLog syslog:local
Since: Apache 1.0
This directive sets the target to which the server will log any errors
it encounters. If target is a file name and does not begin with a
slash (``C''), then it is assumed to be relative to ServerRoot.
If it begins with a pipe (``|''), then it is assumed to be a command
that spawns the errors. Alternatively, target can be
``syslog:facility'', which enables logging via syslog(3) if the
system supports it. The default is to use syslog facility local7.