xref: /csrg-svn/usr.bin/f77/libU77/signal_.c (revision 2544)
12419Sdlw /*
2*2544Sdlw char id_signal[] = "@(#)signal_.c	1.2";
32419Sdlw  *
42419Sdlw  * change the action for a specified signal
52419Sdlw  *
62419Sdlw  * calling sequence:
72419Sdlw  *	integer cursig, signal, savsig
82419Sdlw  *	external proc
92419Sdlw  *	cursig = signal(signum, proc, flag)
102419Sdlw  * where:
112419Sdlw  *	'cursig' will receive the current value of signal(2)
122419Sdlw  *	'signum' must be in the range 0 <= signum <= 16
132419Sdlw  *
142419Sdlw  *	If 'flag' is negative, 'proc' must be an external proceedure name.
152419Sdlw  *
162419Sdlw  *	If 'flag' is 0 or positive, it will be passed to signal(2) as the
172419Sdlw  *	signal action flag. 0 resets the default action; 1 sets 'ignore'.
182419Sdlw  *	'flag' may be the value returned from a previous call to signal.
19*2544Sdlw  *
20*2544Sdlw  * This routine arranges to trap user specified signals so that it can
21*2544Sdlw  * pass the signum fortran style - by address. (boo)
222419Sdlw  */
232419Sdlw 
242419Sdlw #include	"../libI77/f_errno.h"
252419Sdlw 
26*2544Sdlw int (*dispatch[17])();
272419Sdlw int (*signal())();
28*2544Sdlw int sig_trap();
292419Sdlw 
302419Sdlw long signal_(sigp, procp, flag)
312419Sdlw long *sigp, *flag;
322419Sdlw int (*procp)();
332419Sdlw {
342419Sdlw 	if (*sigp < 0 || *sigp > 16)
352419Sdlw 		return(-((long)(errno=F_ERARG)));
362419Sdlw 
372419Sdlw 	if (*flag < 0)	/* function address passed */
38*2544Sdlw 	{
39*2544Sdlw 		dispatch[*sigp] = procp;
40*2544Sdlw 		return((long)signal((int)*sigp, sig_trap) );
41*2544Sdlw 	}
422419Sdlw 
432419Sdlw 	else		/* integer value passed */
442419Sdlw 		return((long)signal((int)*sigp, (int)*flag) );
452419Sdlw }
46*2544Sdlw 
47*2544Sdlw sig_trap(sn)
48*2544Sdlw int sn;
49*2544Sdlw {
50*2544Sdlw 	long lsn = (long)sn;
51*2544Sdlw 	return((*dispatch[sn])(&lsn));
52*2544Sdlw }
53