Hi Blake,
thanks for that information. Actually the SIGINT is delivered to GNU APL as
expected. The problem is that when I return from the GNU APL SIGINT
handler then
readline seems to be blocked in the old readline() call and returns only
after another
char (any char - does not have to be newline) was typed.
/// Jürgen
On 07/21/2014 08:21 PM, Blake McBride wrote:
Does this help?
This may be related to the cooked/uncooked/rare
<http://en.wikipedia.org/wiki/POSIX_terminal_interface#Early_Unices%3a_Seventh_Edition_Unix> terminal
modes; |^C| does not always send a signal. It seems likely that
readline uncooks the terminal, and thus any signals caused by keyboard
input must be due to logic within readline itself; it seems plausible
that it might only trigger a SIGINT on two sequential |^C|s
(especially since for many programs that utilise readline such as
shells and REPLs, the program exiting on a single |^C| would be very
annoying!).
You might be able to change this behaviour by using the readline API
to rebind |^C| to some of your own code that triggers a SIGINT. I
haven't used readline from Haskell, just from C, so I'm not sure
exactly how you'd go about this, but the binding
<http://hackage.haskell.org/packages/archive/readline/latest/doc/html/System-Console-Readline.html> seems
rich enough to achieve it.
On Mon, Jul 21, 2014 at 12:39 PM, Juergen Sauermann
<juergen.sauerm...@t-online.de <mailto:juergen.sauerm...@t-online.de>>
wrote:
Hi David,
I see. The problem is that the line input (readline) does not
return even
though I tell it to (by setting *rl_done* in the signal handler
for ^C). I haven't
found a way to fix this (hints more than welcome). This could also
be caused
by terminal settings ("cooked mode") but I thought readline would
handle this.
Long term I will most likely replace readline because so far it
has created more problems
than it has helped. That would be a bigger issue and should also
be aligned with Elias'
emacs mode. So it would be after the next GNU APL release.
/// Jürgen
On 07/21/2014 06:32 PM, David B. Lamkins wrote:
Thanks, Jüergen.
The real issue, from my perspective, is that APL doesn't report the
ATTENTION message until it sees a newline on input. It seems to me that
typing a ^C should immediately suspend execution and show the ATTENTION
message.
On Mon, 2014-07-21 at 18:23 +0200, Juergen Sauermann wrote:
Hi David,
I have changed readline to display a new line right after ^C, see SVN 382.
For reasons that I don't fully understand, the next character after ^C
will be eaten by
readline; I tried a number of things to prevent this but haven't succeeded.
I believe readline will be one of the next things removed from GNU APL.
/// Jürgen
On 07/21/2014 02:32 AM, David Lamkins wrote:
When the session is not executing APL code, the attention signal is
not handled until the next newline.
To see this, enter the characters Control-C, 1, Return.
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