Is it possible to ignore all signals?

Question

I have a server application which I want to protect from being stopped by any signal which I can ignore. Is there a way to ignore all possible signals at once, without setti

Answer 1

Blocking signals is NOT the same as ignoring them.

When you block signals as suggested by C2H5OH, it gets added to a pending signal queue and will be delivered to the process as soon as you unblock it.

Unblocking can be done using

#include 

sigset_t mask;
sigemptyset(&mask);
sigprocmask(SIG_SETMASK, &mask, NULL);

To answer your question on how to ignore signals, it has to be handled by a Signal Handler which is a user-defined function which executes whenever a signal is delivered to the process

static void foo (int bar)
{
     /*some code here. In your case, nothing*/
}

then register this function by using

signal(SIGINT,foo);   //or whatever signal you want to ignore

If you want to ignore all signals

int i;
for(i = 1; i <=31 ; i++)
{
   signal(i,foo);
}

This code will take all the signals delivered to the process and ignore them instead of blocking them.

NOTE: According to man pages , it is not the recommended way, instead sigaction is suggested. Do check out man sigaction