UNIX for Dummies Questions & Answers

I am curious about HUP..... kill -HUP pid
What exactly does it do?? Does it stop the process and restart it from the beginning or from where it stopped? Thanks

It restarts the process from the begging (reloading any config files it uses)

Code:

/HUP
...skipping
     name. There is no default. Typing kill  does not send a sig-
     nal  to  the  current  job. If the signal being sent is TERM
     (terminate) or HUP (hangup), then the job or process is sent
     a CONT (continue) signal as well.

Was this in the man pages...if so sorry for wasting your time, I was reading about the kill command and I don't have a unix box at my job to use the man command but wanted the answer now, and this site usually gets the answers to my simple questions quickly. Thanks for the info.

for future referance i would also check out solarisguide.com they have online man pages.

I'm curious. I was under the impression that it was simply a certain type of kill signal, in this case on a "hang up", or disconnection by the user running the process. I know certain processes restart on a HUP signal, but is that always the case, or is that simply how they handle that signal in a specific instance? For example , if I killall -HUP inetd, I know it will restart the inted daemon, re-reading all config files. But when I killall -HUP pppd, it literally hangs up...

Am I mistaken?

isnt your pppd something you have to initiate via entering a command to tell it to dial or does it auto connect as soon as the daemon is started?

Well, that was only an example. Regardless, will signal 1 (HUP) always cause a process to restart, or only in some cases? I was under the impression that it killed your processes when you logged out, thus the "nohup" utility for keeping your jobs running upon logout.

For example, if I telnet to nether.net, sign in, and run "mail", it tracks my processes. Say my session is dropped, or I close my session from my end. Isn't the HUP signal sent to "mail" to kill it, as opposed to TERM(15), or INT(2)?

I know that to restart, say, inetd, for example I can kill -1 it, but not all programs follow this convention. Is that correct?