Re: [PATCH] test: Make handling of shell prompts with escapes a little more reliable

[Stefano Brivio <sbrivio@redhat.com>]

On Thu, 23 Nov 2023 12:52:53 +1100
David Gibson <david@gibson.dropbear.id.au> wrote:

> When using the old-style "pane" methods of executing commands during the
> tests, we need to scan the shell output for prompts in order to tell when
> commands have finished.  This is inherently unreliable because commands
> could output things that look like prompts, and prompts might not look like
> we expect them to.  The only way to really fix this is to use a better way
> of dispatching commands, like the newer "context" system.
> 
> However, it's awkward to convert everything to "context" right at the
> moment, so we're still relying on some tests that do work most of the time.
> It is, however, particularly sensitive to fancy coloured prompts using
> escape sequences.  Currently we try to handle this by stripping actual
> ESC characters with tr, then looking for some common variants.
> 
> We can do a bit better: instead strip all escape sequences using sed before
> looking for our prompt.  Or, at least, any one using [a-zA-Z] as the
> terminating character. Strictly speaking ANSI escapes can be terminated by
> any character in 0x40..0x7e, which isn't easily expressed in a regexp.
> This should capture all common ones, though.
> 
> With this transformation we can simplify the list of patterns we then look
> for as a prompt, removing some redundant variants.
> 
> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

I didn't forget about this one, but I had unrelated test failures which
I wasn't sure about. This is actually fine though. Applying soon.

-- 
Stefano