On Fri, Nov 16 2018, Neil Jerram wrote: > Mark H Weaver <m...@netris.org> writes: > >> This is a documented limitation in Linux's terminal handling when in >> canonical mode. See the termios(3) man page, which includes this text: >> >> Canonical and noncanonical mode >> >> The setting of the ICANON canon flag in c_lflag determines >> whether the terminal is operating in canonical mode (ICANON set) >> or noncanonical mode (ICANON unset). By default, ICANON is set. > [...] >> * The maximum line length is 4096 chars (including the >> terminating newline character); lines longer than 4096 chars >> are truncated. After 4095 characters, input processing (e.g., >> ISIG and ECHO* processing) continues, but any input data after >> 4095 characters up to (but not including) any terminating >> newline is discarded. This ensures that the terminal can >> always receive more input until at least one line can be read. >> >> Note that last item above. > > Awesome; thank you Mark. > > So possibly this limit can be removed, in my Org/Geiser context, by > evaluating (system* "stty" "-icanon") when initializing the Geiser-Guile > connection. I'll try that. Will the terminal that that 'stty' sees be > the same as Guile's stdin? > > Jao, if that works, I wonder if it should be the default for Geiser? It > appears to me that Geiser shouldn't ever need the features of canonical > mode. Is that right?
I don't really know offhand. Geiser simply uses comint-mode to talk to Guile, and that in turn must be using Emacs' ability to spawn a process and redirect its stdout and stderr, so I am not sure where the stty kernel side enters the game, and how exactly shuold that call to system* be performed to make sure it only affects the guile-emacs communications. Geiser has a mode of operation whereby it connects to a running Guile REPL server instead of spawning its own process. In that mode, instead of a stdout/err redirection what is used is a TCP/IP connection, that won't have any of this limitations. So a cleaner solution would be to make geiser always use a REPL server for Guile, but that requires some non-trivial work on my side. Another option would be for the org mode package to setup a guile server and then use connect-to-guile (instead of run-guile), but i don't know how difficult that would be. Finally, a shabby workaround would be generating multiple lines instead of a big one :) That's of course not a real solution, but maybe can work as a stopgap. > Anyway, I'll see first if the stty call is effective. Excellent. Thanks for taking the time and please keep us posted! Cheers, jao -- "I don't want to achieve immortality through my work... I want to achieve it through not dying" -- Woody Allen
