Set list of blocked signals.
Source position: bunxh.inc line 23
| function FpSigProcMask( | 
| how: cint; | 
| nset: psigset; | 
| oset: psigset | 
| ):cint; | 
| how: cint; | 
| constref nset: tsigset; | 
| var oset: tsigset | 
| ):cint; | 
Changes the list of currently blocked signals. The behaviour of the call depends on How :
If oset is non-nil, then the old set is stored in it.
Errno is used to report errors.
| 
 | Install signal handler. | |
| 
 | Return set of currently pending signals. | |
| 
 | Set signal mask and suspend process till signal is received. | |
| 
 | Send a signal to a process. |