One way to "talk" to a daemon is to use signals. Such as doing something like "kill -HUP $(cat pid-of-syslogd) to tell syslogd to restart an reread its configuration file. I've seen other daemons which use SIGUSR1 or SIGUSR2. But that's like the old style beepers. It could only say "call this number", but didn't tell you anything else. Unlike today's SMS text messages which send a sound, the originating number, and a short message. Is there anything conceptually like this for telling a daemon to "do something" where the "something" could be 1 of 100s of different actions (such as restart, stop, dump status variables to syslogd, verify if a specific user is using the daemon (logged on in some sense) )?
Or should I look at this more like, say PostgreSQL does, and listen on a TCPIP port and/or maybe a UNIX socket? As an aside, does anybody use UNIX message queues any more? I can find some information on them via Google, but I'm not aware of any actual application on my Linux system which uses them. Assume for the nonce that I am only speaking of IPC within a given system. -- Maranatha! <>< John McKown ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
