Eric Blake wrote: > POSIX requires [n]>&- and [n]<&- redirection operators to close > the respective stream, even when n is 0, 1, or 2. POSIX allows an > implementation to supply replacement file descriptors when exec'ing a > setuid or setgid program. But in the normal case, implementations really > do allow you to start life with any of the three standard streams closed.
Thanks for explaining. I wasn't aware that sh has built-in operators for doing this. > that doesn't mean GNU programs can't be robust against it. OK, but what is the correct behaviour? Signal an error? $ cp --help >&- ; echo $? cp: write error: Bad file descriptor 1 or treat it like /dev/null? $ cp --help >&- ; echo $? 0 Bruno
