Re: why is the pipeline_pgrp reset to 0 only when the pipeline_pgrp and shell_pgrp are different

[alex xmb ratchev]

im not related , but , you sent & nbsp ; html containing
send file

On Wed, Mar 15, 2023, 3:42 PM wang yuhang via <help-bash@gnu.org> wrote:

> Hello
>
> I use the fork bomb to start the process. When the number of processes
> reaches the maximum limit with command "ulimit -u". In bash version 5.1,
> function terminate_current_pipeline does not send sigterm signal, just
> because pipeline_ pgrp is the same with shell_pgrp.
>
>
> I found bash-5.1 the following difference compared with bash-5.0
> ```
> +jobs.c
> +       - {start,stop}_pipeline: don't reset pipeline_pgrp to 0 if it's
> already
> +       &nbsp; the same as shell_pgrp, since we don't want to reset it in
> the middle
> +       &nbsp; of a shell started to run a command or process substitution
> (after
> +       &nbsp; forking a child to run one command, but before forking
> another, for
> +       &nbsp; instance). Reported by Rob Landley <rob@landley.net&gt;
> ```
>
>
> ```
> diff --git a/jobs.c b/jobs.c
> index b791900..f98e2e6 100644
> --- a/jobs.c
> +++ b/jobs.c
> @@ -519,7 +519,12 @@ start_pipeline ()
> &nbsp; &nbsp;if (the_pipeline)
> &nbsp; &nbsp; &nbsp;{
> &nbsp; &nbsp; &nbsp; &nbsp;cleanup_the_pipeline ();
> -&nbsp; &nbsp; &nbsp; pipeline_pgrp = 0;
> +&nbsp; &nbsp; &nbsp; /* If job_control == 0, pipeline_pgrp will always be
> equal to shell_pgrp;
> +        if job_control != 0, pipeline_pgrp == shell_pgrp for command and
> +        process substitution, in which case we want it to be the same as
> +        shell_pgrp for the lifetime of this shell instance. */
> +&nbsp; &nbsp; &nbsp; if (pipeline_pgrp != shell_pgrp)
> +       pipeline_pgrp = 0;
> &nbsp;#if defined (PGRP_PIPE)
> &nbsp; &nbsp; &nbsp; &nbsp;sh_closepipe (pgrp_pipe);
> &nbsp;#endif
> @@ -632,7 +637,8 @@ stop_pipeline (async, deferred)
> &nbsp;
> &nbsp; &nbsp; &nbsp; &nbsp;the_pipeline = (PROCESS *)NULL;
> &nbsp; &nbsp; &nbsp; &nbsp;newjob-&gt;pgrp = pipeline_pgrp;
> -&nbsp; &nbsp; &nbsp; pipeline_pgrp = 0;
> +&nbsp; &nbsp; &nbsp; if (pipeline_pgrp != shell_pgrp)
> +       pipeline_pgrp = 0;
> &nbsp;
> &nbsp; &nbsp; &nbsp; &nbsp;newjob-&gt;flags = 0;
> &nbsp; &nbsp; &nbsp; &nbsp;if (pipefail_opt)
>
> ```
>
>
> I'm sorry I can't find the original issue. Could you tell me why is the
> pipeline_pgrp reset to 0 only when the pipeline_pgrp and shell_pgrp are
> different?&nbsp;
>
>
> Thanks !