Re: conf: flush stdout before early exit

[Paul Holzinger <pholzing@redhat.com>]

Hi,

On 29/05/2025 19:08, Jon Maloy wrote:
> Before doing an early exit any contents of stdout is normally flushed.
> This doesn't happen when the output goes into a pipe and we return with
> _exit(). We now add an explicit flush in such cases.
>
> Fixes: d0006fa784a7 ("treewide: use _exit() over exit()")
>
> Signed-off-by: Jon Maloy <jmaloy@redhat.com>

Reviewed-by: Paul Holzinger <pholzing@redhat.com>

Interestingly enough I never noticed that I broke podman info with this:

podman info --format "{{.Host.Pasta.Version}}"

The output is empty currently due this issue and works with this patch 
again.

> ---
>   conf.c | 3 +++
>   1 file changed, 3 insertions(+)
>
> diff --git a/conf.c b/conf.c
> index a6d7e22..a1d55a3 100644
> --- a/conf.c
> +++ b/conf.c
> @@ -975,6 +975,7 @@ static void usage(const char *name, FILE *f, int status)
>   		"    SPEC is as described for TCP above\n"
>   		"    default: none\n");
>   
> +	fflush(f);
>   	_exit(status);
>   
>   pasta_opts:
> @@ -1029,6 +1030,7 @@ pasta_opts:
>   		"  --ns-mac-addr ADDR	Set MAC address on tap interface\n"
>   		"  --no-splice		Disable inbound socket splicing\n");
>   
> +	fflush(f);
>   	_exit(status);
>   }
>   
> @@ -1594,6 +1596,7 @@ void conf(struct ctx *c, int argc, char **argv)
>   			FPRINTF(stdout,
>   				c->mode == MODE_PASTA ? "pasta " : "passt ");
>   			FPRINTF(stdout, VERSION_BLOB);
> +			fflush(stdout);
>   			_exit(EXIT_SUCCESS);
>   		case 15:
>   			ret = snprintf(c->ip4.ifname_out,

-- 
Paul Holzinger