[PATCH] Insert \n before cmd output when input is not a tty.

[Valerie Aurora]

On Fri, Mar 28, 2025 at 7:20 PM Auke Kok <auke.kok at versity.com> wrote:
>
> The output of piped input commands used by the tests is causing the
> output to be concatenated on the line unless the cmd output itself
> contains newlines. This is because when input is a pipe, we're not going
> to be outputting the cmd's implicit newline.
>
> This makes the output of test scripts a little awkward to read as we're
> seeing test output that is relevant pre-pended with several <> line
> headings.
>
> Use `isatty()` to detect whether stdin is a pipe or not, and insert an
> extra newline before outputting cmd output resolves this.
>
> Signed-off-by: Auke Kok <auke.kok at versity.com>
> ---
>  cli/debugfs.c | 7 +++++++
>  1 file changed, 7 insertions(+)
>
> diff --git a/cli/debugfs.c b/cli/debugfs.c
> index 8271148..f2ac71c 100644
> --- a/cli/debugfs.c
> +++ b/cli/debugfs.c
> @@ -807,6 +807,10 @@ static void debugfs_thread(struct thread *thr, void *arg)
>         char **line_argv = NULL;
>         char *line = NULL;
>         int ret;
> +       bool is_tty;
> +
> +       /* if our stdin is not a tty, we want to insert newlines after each cmd */
> +       is_tty = isatty(fileno(stdin));
>
>         line = malloc(LINE_SIZE);
>         line_argv = calloc(MAX_ARGC, sizeof(line_argv[0]));
> @@ -824,6 +828,9 @@ static void debugfs_thread(struct thread *thr, void *arg)
>                 if (!fgets(line, LINE_SIZE, stdin))
>                         break;
>
> +               if (!is_tty)
> +                       fprintf(stdout, "\n");
> +
>                 parse_command(ctx, line, line_argv);
>
>                 if (ctx->quit)
> --
> 2.47.1

Thanks for this, this problem has been annoying me. I put it in my
tree where it has already helped me debug something.

Valerie