1 /* 2 char id_signal[] = "@(#)signal_.c 1.4"; 3 * 4 * change the action for a specified signal 5 * 6 * calling sequence: 7 * integer cursig, signal, savsig 8 * external proc 9 * cursig = signal(signum, proc, flag) 10 * where: 11 * 'cursig' will receive the current value of signal(2) 12 * 'signum' must be in the range 0 <= signum <= 16 13 * 14 * If 'flag' is negative, 'proc' must be an external proceedure name. 15 * 16 * If 'flag' is 0 or positive, it will be passed to signal(2) as the 17 * signal action flag. 0 resets the default action; 1 sets 'ignore'. 18 * 'flag' may be the value returned from a previous call to signal. 19 * 20 * This routine arranges to trap user specified signals so that it can 21 * pass the signum fortran style - by address. (boo) 22 */ 23 24 #include "../libI77/f_errno.h" 25 26 static int (*dispatch[17])(); 27 int (*signal())(); 28 int sig_trap(); 29 30 long signal_(sigp, procp, flag) 31 long *sigp, *flag; 32 int (*procp)(); 33 { 34 int (*oldsig)(); 35 int (*oldispatch)(); 36 37 oldispatch = dispatch[*sigp]; 38 39 if (*sigp < 0 || *sigp > 16) 40 return(-((long)(errno=F_ERARG))); 41 42 if (*flag < 0) /* function address passed */ 43 { 44 dispatch[*sigp] = procp; 45 oldsig = signal((int)*sigp, sig_trap); 46 } 47 48 else /* integer value passed */ 49 oldsig = signal((int)*sigp, (int)*flag); 50 51 if (oldsig == sig_trap) 52 return((long)oldispatch); 53 return((long)oldsig); 54 } 55 56 sig_trap(sn) 57 int sn; 58 { 59 long lsn = (long)sn; 60 return((*dispatch[sn])(&lsn)); 61 } 62