2018-04-28 00:23:51 +0200, Martijn Dekker:
[...]
> That said, do you have any opinion on whether something like
> { ... ; } 3>&-
> should push/restore a closed file descriptor if it's already closed, so that
> the effect of exec-ing that descriptor within the compound command is local
> to that compound command?
[...]
Actually, in my list of "issues" I plan to some day raise to the
Austin Group, I had:
sh -c '{ exec > a; } > b; echo x' > c
which sounds like it's the same.
Do we honour the compound command asking for stdout to be
redirected, or do we honour the "> b" redirection being
temporary and apply only to the command substitution?
I'm undecided here, though I'd tend to lean the same way as you
do.
The problem can also be expressed as:
redir_stdout() {
exec > "$1"
}
redir_stdout file1 > file2
Or:
close() { eval "exec $1>&-"; }
close 1 > file
f() {
close 1
redir_stdout file
echo foo
close 1
}
f > /dev/null
POSIX could arbitrate based on the number of implementations
that go one or the other way. Or leave it unspecified (I've not
checked what it currently says)..
--
Stephane
