On 2023-06-24 00:12, Kevin Schnitzius wrote:
On Friday, June 23, 2023 at 10:00:02 PM EDT, Chris Roehrig via Cygwin
<cygwin@cygwin.com> wrote:
Thanks. There must be some issue with my setup. Very odd that 'pv'
works, but 'cat' does not. ldd shows they use identical libs. I guess
I'll start with the pv and cat source.
Try this first:
/usr/bin/dd if=/dev/zero bs=1 count=65536 | /usr/bin/ssh localhost '/usr/bin/cat
> /dev/null'
Good thought. No change. NB: 65536 always works fine. Anything
greater (e.g. 65537) does not work.
Also, I assume you are running Cygwin's bash in a mintty term...
Yes, same results with both mintty (Administrator or not) or slogged in
remotely.
I found another one that works: tee.
So these work fine (and /dev/null can be replaced by any file or
omitted; doesn't matter):
dd if=/dev/urandom bs=1 count=65537 | ssh localhost 'wc' # WORKS
dd if=/dev/urandom bs=1 count=65537 | ssh localhost 'tee /dev/null | cat
> /dev/null' # WORKS
dd if=/dev/urandom bs=1 count=65537 | ssh localhost 'pv | cat >
/dev/null' # WORKS
dd if=/dev/urandom bs=1 count=65536 | ssh localhost 'cat > /dev/null'
# WORKS
These don't:
dd if=/dev/urandom bs=1 count=65537 | ssh localhost 'cat | wc' # STALLS
dd if=/dev/urandom bs=1 count=65537 | ssh localhost 'cat > /dev/null'
# STALLS
dd if=/dev/urandom bs=1 count=65537 | ssh localhost 'awk {print} >
/dev/null' # STALLS
dd if=/dev/urandom bs=1 count=65537 | ssh localhost 'sed {} > /dev/null'
# STALLS
So pv, tee, and wc work, but cat, sed, awk get hung up.
I also tried a simple python 3.9 implementation of 'cat' which works,
and a gcc-compiled getchar/putchar one which stalls (which gives me
something to work with).
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