Re: Pipe after Command Substitution does not resolve the substitution:

[Brian Inglis <Brian dot Inglis at SystematicSw dot ab dot ca>]

On 2017-06-14 01:41, Jon Bord wrote:
> Windows 10
> bash 4.4.11(2) and 4.4.12(3)

Better to just run the commands and post the output e.g.:

$ cmd /c ver

Microsoft Windows [Version 10.0.14393]
$ uname -svrmo
CYGWIN_NT-10.0 2.8.0(0.309/5/3) 2017-04-01 20:47 x86_64 Cygwin
$ bash --version
GNU bash, version 4.4.12(3)-release (x86_64-unknown-cygwin)
Copyright (C) 2016 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later
<http://gnu.org/licenses/gpl.html>

This is free software; you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

and run and attach output as text:
$ cygcheck -svr > cygcheck.out

> $ set -xv
> (EXAMPLE 1: COMMAND SUBSTITUTION WORKS AS EXPECTED)
> $ grep 2 $(ls | tail -1)
> grep 2 $(ls | tail -1)
> ++ ls
> ++ tail -1
> + grep 2 test.txt
> 2
> 23
> (EXAMPLE 2: HANGS)
> $ grep 2 $(ls | tail -1)  | grep 3
> grep 2 $(ls | tail -1)  | grep 3
> + grep 3
> + grep 2
> (EXAMPLE 3: HANGS)
> $ grep 2 `ls | tail -1` | grep 3
> grep 2 `ls | tail -1` | grep 3
> + grep 3
> + grep 2

$ cat z
1
2
3
12
23
13
$ grep 2 `ls | tail -1` | grep 3
23

WFM!
Command substitution adds arguments to the command line and does not
interfere with pipes.

> SPECULATION: i had wondered if the cause was a change in version of
> bash but i cannot be sure what the version was that i was using on
> Windows 7. I wish i had a record. I've tried this on both 4.4.11(2)
> and 4.4.12(3). My instincts are that it is not, that it is Cygwin (or
> more precisely bash.exe?) on Windows 10 instead. I have noticed other
> differences / problems, eg arrow keys behaving oddly in vi, and
> general sluggishness (but not tested yet).

Cygwin 32?
Run "rebase-trigger full", shut down all Cygwin processes, download and
run setup to do a full rebase, and retry.

AV?
BLODA?
https://cygwin.com/faq/faq.html#faq.using.bloda
Fork problems are often a symptom of poorly written software like those
listed.

-- 
Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada

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