hello,

i have a small suggestion to make (slightly off topic):

i think this problem would be best solvable by having nginx capable of logging
to a file-type other than a regular file. for instance, if the nginx error_log directive
(http://wiki.codemongers.com/NginxMainModule#error_log) could support a TCP/IP
or a unix domain socket or a named pipe, then interesting programs can be
written around it which may be an easy approach:

a) for instance, having an external program monitor nginx logs for a particular
log message (or "event"), is not so easy when the file in question is a regular
file. the reason for that is, regular files are *always* ready to read on linux
(even if the FD is at EOF), so you can't use an open file descriptor to a
regular file in a select()/poll() system call and expect it to work the way you
want. (i.e. ready-to-read) it could be done (tail -f does that), but it's rather messy to have a
file-change notification, plus seeking to the appropriate offset. -- with
sockets/fifos, these problems can go away. you can set up a socket server to
listen on the given socket for connections, and when nginx starts up, the error
log initialization code can connect to the tcp or unix domain socket or fifo in
question, and then all calls to nginx_log_* will naturally be written to the
socket, instead of written to a regular file