On Fri, Aug 13, 2010 at 1:25 PM, Eric Blake <ebl...@redhat.com> wrote:
> Then again, cat should exist until something causes the input side of
> its pipe to declare EOF; so I guess there's no race in this example
> after all. Rather, it looks like a limitation in cygwin1.dll. I don't
> know why bash is unable to duplicate the output end of the pipe to the
> echo process, unless cygwin's /dev/fd handling doesn't work on pipes.
> But that's highly likely that you are dealing with yet another one of
> cygwin's pipe handling shortfalls.
Would these shortfalls also explain why this script doesn't do what
I'd expect (that is, output "hello" and exit)? It just hangs right now
--- this is the ps output:
I 8580 7740 7740 6340 3 4412345 13:41:41 /usr/bin/cygpath
I 7724 7740 7740 4796 3 4412345 13:41:41 /usr/bin/cygpath
O 1736 7740 7740 8796 3 4412345 13:41:41 /usr/bin/echo
So, err, echo is waiting to output, and cygpath is waiting to receive
input? I don't see why the script shouldn't be making forward
progress.
#!/bin/bash
tmpdir=$(mktemp -dt cygfilter-XXXXXX)
stdout_pid=
stderr_pid=
function cleanup() {
[[ -n $stdout_pid ]] && /bin/kill $stdout_pid
[[ -n $stderr_pid ]] && /bin/kill $stderr_pid
rm -rf "$tmpdir"
}
trap cleanup 0
mkfifo "$tmpdir/f-out"
mkfifo "$tmpdir/f-err"
cygpath -u -f "$tmpdir/f-out"&
stdout_pid=$!
disown %%
cygpath -u -f "$tmpdir/f-err" >&2 &
stderr_pid=$!
disown %%
"$@" >"$tmpdir/f-out" 2>"$tmpdir/f-err"
# Run as cygfilter /bin/echo hello
# -----------
--
Problem reports: http://cygwin.com/problems.html
FAQ: http://cygwin.com/faq/
Documentation: http://cygwin.com/docs.html
Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple
