2.9BSD - /usr/src/lib/libF77/signal_.c

   1: /*
   2:  *	"@(#)signal_.c	1.1"
   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: }

Defined functions