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

[Marco Atzeri <marco.atzeri@gmail.com>]

On 14/06/2017 09:41, Jon Bord wrote:
> Hi,
>
> This is the first time i've ever submitted a bug report so i hope the
> below is ok. I am not a programmer although i do do some scripting.
>
> The below is the kind of 'command substitution then pipe' that i often
> used in Cygwin on Windows 7.  Now that i've been forced to move to
> Windows 10 it no longer seems to work. I'm assuming that this is not a
> feature of an upgraded Bash but maybe i'm wrong, eg maybe we are now
> supposed to put everything in variables rather than use command
> substitution.
>
> Windows 10
> bash 4.4.11(2) and 4.4.12(3)
>
> $ 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
>
> Would it be correct to conclude from the above output that once the
> pipe is added then it is ignoring the substitution?
>

Hi Jon,
all the examples work for me on W7 64 with cygwin 64bit.

  $ ls
prova.txt

$ cat prova.txt
1
2
3
23

$ grep 2 $(ls | tail -1)
2
23

$ grep 2 $(ls | tail -1)  | grep 3
23

$ grep 2 `ls | tail -1` | grep 3
23

can you provide your cygcheck.out  ?
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