Make a system call to the host OS, returning a status
See sys-call+ for a closely related utility. There are only
the following two differences between between sys-call* and
- Both return an error-triple (mv erp val state), but for
sys-call*, val is always nil. (For sys-call+, val is
the string produced as output by the command.)
- Logically, sys-call* pops the oracle once, not twice.