signal & sigvec error return codes

[Tom Stockfisch]

In article <8044 at batcomputer.tn.cornell.edu> lijewski at batcomputer.tn.cornell.edu (Mike Lijewski) writes:
_     Do all vendors still document the return code of signal and
_sigvec as being -1 (implicitely an int)?  My problem with this is
_that if you try to be a "good" programmer and check for an error as
_in 
_    if(signal(SIGINT, SIG_IGN) == -1){
_      perror("signal");
_      exit(1);
_    }
_say, you will either get a warning or an error, depending on how smart
_your compiler is.  Why not document the error return as being something
_along the lines of SIG_ERR, where SIG_ERR is defined as
_#define SIG_ERR ((int(*)())-1)
_in <signal.h>?

This last cast gets warnings from many compilers (e.g. gcc).

Why isn't this implemented without the potentially unportable
and kludgey cast of -1?

signal.h:
	int	SIG_ERR(), SIG_IGN(), SIG_DFL();

signal.c:
	int	SIG_ERR(){assert(0);}
	int	SIG_IGN(){assert(0);}
	int	SIG_DFL(){assert(0);}
-- 

|| Tom Stockfisch, UCSD Chemistry	tps at chem.ucsd.edu