[ADMIN] logfile problem?

[tw_vincent]

Dear All:           I start postgresql with "/app/pgsql/bin/pg_ctl start -l /app/pgsql/logfile -D /app/pgsql/data", when I use "cat /dev/null > /app/pgsql/logile" to clear logfile, I can't clear logfile. How can I clear the logfile, thank you!   vincent