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From: arup@grad1.cis.upenn.edu (Arup Mukherjee)
Newsgroups: comp.unix.questions
Subject: problems with SIGALRM.....
Message-ID: <9709@netnews.upenn.edu>
Date: 8 Apr 89 22:58:35 GMT
Sender: news@netnews.upenn.edu
Reply-To: arup@grad1.cis.upenn.edu.UUCP (Arup Mukherjee)
Distribution: na
Organization: University of Pennsylvania
Lines: 47


Dear netlanders,
        Can anyone tell me what is wrong with the following program?
It works fine under Ultrix 3.0 but not under earlier versions of
Ultrix. It also does not work under SunOS 4.0. Am I making some kind
of mistake, or is this a known bug? If so, are there any workarounds
that will allow SIGALRM to work properly. (Note that if I try to trap,
for example, SIGSEGV instead, and then generate a segmentation violation on 
purpose, it works on any machine).


				Thanks very much....
						
						Arup Mukherjee
					[arup@grasp.cis.upenn.edu]
---cut here---

# include <stdio.h>
# include <signal.h>

struct sigvec f;

int handler()
{
	fprintf (stderr, "I got a signal!\n");
	fflush(stderr);
}

main()
{

# ifdef TRY2                             /* neither of these two work on */
	f.sv_handler = handler;          /* most machines I tried        */
	f.sv_mask = 0;
	f.sv_onstack = 0;                /* Under Ultrix 3.0 on a        */
                                         /* uVax 3500, both work ok      */
        sigvec (SIGALRM, &f, NULL);
# else 
	signal (SIGALRM, handler);
# endif  
	

	alarm(1);
	sleep(10);


}