- Use MAP_FAILED instead of the constant -1 to indicate
failure (required by POSIX).
- Removed flag arguments of '0' (required by POSIX).
- Fixed code which expected an error return of 0.
- Fixed code which thought any address with the high bit set
was an error.
- Check for failure where no checks were present.
Discussed with: bde
- timeval in select loop was depending on not having the remaining time
returned from select(), causing a busy spin on an implementation that
does implement it.
- the err() usage was pretty bogus, some of the error messages had
strerror attached manually and then reattached by err().
