administering open files

[00704a-Krakman]

	I want to chop down the size of a file that is being written to by a 
currently running process - actually one that is running out of /etc/inittab
and may never die. Here are some possibilities:

testprog > logfile &

1) mv logfile old.log
   >logfile

	This appears to work but I don't know how it could! When you create
	the logfile in the second line it should have a different inode than
	the one the testprog process knows about. So how can the testprog
	write to the "correct" logfile?

2) To administer the /usr/lib/cron/log file, the UNIX System V Release 3 System
Administrator's guide says to put this entry in your cronfile:
	
	tail -100 /usr/lib/cron/log > /tmp/log;mv /tmp/log /usr/lib/cron/log

	If /etc/cron always has this log open (I'm assuming it does), than 
	won't it also be writing to the wrong file? It should have no way
	of knowing the inode of the "new" /usr/lib/cron/log



			Thanks ahead of time,

					Ken Krakman
					att!ihlpf!kmk