[Techtalk] sighup, kill -9, sigkill, and all those related things

lisab at bluesunsa.com lisab at bluesunsa.com
Fri Apr 14 07:34:42 EST 2006


>
> Cynthia Kiser wrote:
>> But it still left me wondering about the difference between
>> kill's 1-3.
>
> from "man 7 signal"
>
> Signal     Value     Action   Comment
> SIGHUP        1       Term    Hangup detected on controlling terminal
>                               or death of controlling process
> SIGINT        2       Term    Interrupt from keyboard
> SIGQUIT       3       Core    Quit from keyboard
>
> Hangup detected on controlling terminal usually means that someone has
> logged out.  If you start a background process and log out, the background
> process will terminate.  Thats why the nohup command was invented many
> years go ago.
>
> If you run "stty -a" you'll see what keys maps to different keyboard
> events.
> I have intr=^C and quit=^\ where ^ = control.
>
> If I have a running process and type Ctrl-C, it will get SIGINT which
> normally causes it to terminate.  If I type Ctrl-\, it will generate a
> core file and exit.
>
> Applications can override most default signal handlers (SIGTERM cannot)
> via fun functions like sigaction().

Thanks Kathryn!  This was incredibly useful.

Lisa


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