On 28/04/2021 16:36, Takashi Yano wrote:
On Wed, 28 Apr 2021 15:38:13 +0200
M2 via Cygwin <cygwin@cygwin.com> wrote:
Hi,
I found a possible regression issue between cygwin 3.1.7-1 and 3.2.0-1.
The issue happens with "short" output in multiple piping, such as the following
example:
dir | grep c | sed "s/^/foo/" | sed "s/oo/OO/"
(the case I run is different, but the bug is exposed by something silly/simple
as this)
In 3.1.7, all is fine and you get what you expect.
In 3.2.0, 3 out of 4 executions hang: the last command on the pipeline (i.e. `sed
"s/oo/OO/"`)
hangs forever, while all preceding commands (i.e. both `grep c` and `sed
"s/^/foo/"`) terminate correctly.
Attached, cygcheck outputs for both 3.1.7 and 3.2.0
I cannot reproduce your problem.
In 64 bit cygwin:
...
In 32 bit cygwin:
...
Some clarification: I run a mixed configuration with Cygwin commands
mostly ran in CMD.EXE shell.
In my installation it seems that output from a WINDOWS console program
causes trouble when piped to a CYGWIN process.
Close repetition such as loops tend to cause the bug.
Consider the following cases. I have CYGWIN\BIN in my (CMD) PATH, and
drive prefix set to "/"
Case 1: BASH shell - all CYGWIN commands - WORKS
for i in {1..20} ; do ls -la | grep . | sed s/./foo/ | sed s/oo/OO/ ; done
Case 2: BASH shell - first command is a WINDOWS command - WORKS
for i in {1..20} ; do /c/windows/system32/ipconfig.exe /all | grep . |
sed s/./foo/ | sed s/oo/OO/ ; done
Case 3: CMD shell - all CYGWIN commands - WORKS
for /l %i in (1,1,20) do ls -la | grep . | sed s/./foo/ | sed s/oo/OO/
Case 4: CMD shell - first command is a WINDOWS command - HANGS 50% of times
for /l %i in (1,1,20) do ipconfig.exe /all | grep . | sed s/./foo/ |
sed s/oo/OO/
Thanks!
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