1 /* 2 * Copyright (c) 1980 Regents of the University of California. 3 * All rights reserved. The Berkeley software License Agreement 4 * specifies the terms and conditions for redistribution. 5 * 6 * @(#)signal_.c 5.3 09/11/85 7 * 8 * change the action for a specified signal 9 * 10 * calling sequence: 11 * integer cursig, signal, savsig 12 * external proc 13 * cursig = signal(signum, proc, flag) 14 * where: 15 * 'cursig' will receive the current value of signal(2) 16 * 'signum' must be in the range 0 <= signum <= 32 17 * 18 * If 'flag' is negative, 'proc' must be an external proceedure name. 19 * 20 * If 'flag' is 0 or positive, it will be passed to signal(2) as the 21 * signal action flag. 0 resets the default action; 1 sets 'ignore'. 22 * 'flag' may be the value returned from a previous call to signal. 23 * 24 * This routine arranges to trap user specified signals so that it can 25 * pass the signum fortran style - by address. (boo) 26 */ 27 28 #include "../libI77/f_errno.h" 29 30 static int (*dispatch[33])(); 31 int (*signal())(); 32 int sig_trap(); 33 34 long signal_(sigp, procp, flag) 35 long *sigp, *flag; 36 int (*procp)(); 37 { 38 int (*oldsig)(); 39 int (*oldispatch)(); 40 41 oldispatch = dispatch[*sigp]; 42 43 if (*sigp < 0 || *sigp > 32) 44 return(-((long)(errno=F_ERARG))); 45 46 if (*flag < 0) /* function address passed */ 47 { 48 dispatch[*sigp] = procp; 49 oldsig = signal((int)*sigp, sig_trap); 50 } 51 52 else /* integer value passed */ 53 oldsig = signal((int)*sigp, (int)*flag); 54 55 if (oldsig == sig_trap) 56 return((long)oldispatch); 57 return((long)oldsig); 58 } 59 60 sig_trap(sn) 61 int sn; 62 { 63 long lsn = (long)sn; 64 return((*dispatch[sn])(&lsn)); 65 } 66