[tlug] UNIX signals

[Jim <jep200404@example.com>]

Evan Monroig <evan.monroig@example.com> wrote:

> The way I did [restarted sshd] was ok with my personal
> server/computer, but a HUP signal certainly seems better for a
> production server !

Why? 

> ... man pages ... Except that they
> all say that HUP is useful, I don't find the documentation very
> meaningful to me when trying to understand the difference between
> signals. Should that be filed as a bug?

No. Explaining signals is too much for a man page. 
You need a big long explanation to _understand_ signals. 
I'm sure there are such on the web, but I'm not aware of them. 
You'll have to dig. I have the dead tree explanations: 

   Advanced Programming in the UNIX Environment, 2nd Ed. Stevens, Rago
   Advanced UNIX Programming, 2nd Ed. Rochkind
   The Design of the UNIX Operating System, Maurice J. Bach

> However, I found the description in the apache doc [1]:
> 
>   Sending the HUP signal to the parent causes it to kill off its
>   children like in TERM but the parent doesn't exit. It re-reads its
>   configuration files, and re-opens any log files. Then it spawns a new
>   set of children and continues serving hits. 

Each program can handle HUP signals however it wants. 
What you quoted is how _Apache_ handles signals. 
Other programs likely handle signals differently.