On 6/22/21 4:31 AM, Greg Wooledge wrote:
On Tue, Jun 22, 2021 at 02:42:40AM -0700, Martin Jambon wrote:
I ran into something that looks like a bug to me, although I'm not super
familiar curly-brace command groups.
Bash version: latest from GitHub mirror (commit ce23728: Bash-5.1 patch 7)
Minimal repro:
$ sleep 1 & { wait $!; } | cat
[1] 665454
bash: wait: pid 665454 is not a child of this shell
I was expecting a success, just like we get without the pipeline:
A pipeline creates two or more subshells, one for each command in the
pipeline. Therefore, your wait command is running in a different
process than the one which created the sleep background job.
The curly braces are irrelevant here.
unicorn:~$ sleep 1 & wait "$!"|cat
[1] 1290127
bash: wait: pid 1290127 is not a child of this shell
Thank you! Now I know that a subshell is not a shell, $$ being the
process ID of the shell, not of the subshell.
