stty -cooked not usable since cygwin-3.1.1-1

[Takashi Yano]

On Tue, 28 Jul 2020 21:51:33 +0200
Rabbe Fogelholm wrote:
> On 2020-07-28 18:56, Thomas Wolff wrote:
> > Am 28.07.2020 um 18:38 schrieb Takashi Yano via Cygwin:
> >> On Tue, 28 Jul 2020 15:56:54 +0200
> >> Rabbe Fogelholm wrote:
> >>> Rabbe Fogelholm wrote:
> >>>> Takashi Yano wrote:
> >>>>> On Mon, 13 Jan 2020 11:52:43 +0100
> >>>>> Rabbe Fogelholm wrote:
> >>>>>> I am running a console Java program that is started from a 
> >>>>>> shellscript
> >>>>>> wrapper. Before invoking Java the wrapper calls `stty -cooked'. 
> >>>>>> The Java
> >>>>>> program polls the keyboard using System.in.available() and reads
> >>>>>> characters immediately using System.in.read(), without waiting for 
> >>>>>> the
> >>>>>> Enter key to be pressed.
> >>>>>>
> >>>>>> This way of combining `stty -cooked' and Java has stopped working 
> >>>>>> since
> >>>>>> version 3.1.1-1 of the Cygwin package. The Java thread that reads the
> >>>>>> keyboard hangs until Enter is pressed, which is not desirable.
> >>>>>>
> >>>>>> I had to downgrade to version 3.0.7-1 to resolve the problem.
> >>>>>>
> >>>>>> Versioning information:
> >>>>>>
> >>>>>> java version "1.8.0_202"
> >>>>>> Java(TM) SE Runtime Environment (build 1.8.0_202-b08)
> >>>>>> Java HotSpot(TM) 64-Bit Server VM (build 25.202-b08, mixed mode)
> >>>>>>
> >>>>>> OS Name: Microsoft Windows 10 Pro
> >>>>>> Version: 10.0.17763 Build 17763
> >>>>>> System Type: x64-based PC
> >>>>>>
> >>>>>> See also the enclosed cygcheck.out.
> >>>>>>
> >>>>>> To demonstrate the issue I enclose a small Java program that 
> >>>>>> should be
> >>>>>> able to read single keystrokes when `stty -cooked' is in effect.
> >>>>> Does your java program work in command prompt? cygwin 3.1.x uses
> >>>>> pseudo console, so the native (non cygwin) program works as if it
> >>>>> is executed in command prompt.
> >>>>>
> >>>> With cygwin 3.1.x I can't find a way to make my program work.
> >>>>
> >>>> When running from within a Cygwin64 terminal the `stty -cooked' command
> >>>> terminates with exit code 0, but the Java program behaves just as if
> >>>> `stty -cooked' is not in effect: It does not handle single keystrokes
> >>>> immediately.
> >>>>
> >>>> When running from a Windows command prompt I can execute the stty
> >>>> program as \cygwin64\bin\stty. However, when given the '-cooked'
> >>>> argument it complains:
> >>>> /usr/bin/stty: 'standard input': unable to perform all requested 
> >>>> operations
> >>>>
> >>>> - and here as well the Java program behaves as if `stty -cooked' is not
> >>>> in effect.
> >>> Some time has passed; I am just curious if anyone may have found a
> >>> solution to the "stty -cooked" issue. With cygwin-3.0.* it was possible
> >>> to have a Java program act on single keystrokes, with cygwin-3.1 I don't
> >>> know how to do it. Any ideas welcome!
> >> Solution 1:
> >> Redesign your java program using JNA with kbhit()/getch() instead of
> >> System.in.available()/System.in.read().
> >>
> >> Solution 2:
> >> Add SetConsoleMode() call with ENABLE_LINE_INPUT flag cleared using JNA.
> > Couldn't cygwin clear this flag when it sets up ConPTY while the pty is 
> > in raw mode?
> > Thomas
> > 
> >>
> >> Solution 3:
> >> Use a wrappwer instead of stty such as:
> >>
> >> #include <stdio.h>
> >> #include <unistd.h>
> >> #include <termios.h>
> >> #include <string.h>
> >> #include <pthread.h>
> >> #include <sys/wait.h>
> >>
> >> void *fwd(void *param)
> >> {
> >>      FILE *f = (FILE *) param;
> >>      char buf[128];
> >>      int len;
> >>      while (1) {
> >>          if ((len = read(0, buf, sizeof(buf))) <= 0) break;
> >>          if (write(fileno(f), buf, len) < len) break;
> >>      }
> >>      return NULL;
> >> }
> >>
> >> int main(int argc, char *argv[])
> >> {
> >>      FILE *f;
> >>      int i;
> >>      pthread_t th;
> >>      struct termios t, t_orig;
> >>      char cmd[1024] = {0, };
> >>      if (argc < 2) return 0;
> >>      for (i = 1; i < argc && strlen(cmd)+strlen(argv[i]) < 
> >> sizeof(cmd)-2; i++) {
> >>          sprintf(cmd + strlen(cmd), (i>1)?" %s":"%s", argv[i]);
> >>      }
> >>      f = popen(cmd, "w");
> >>      tcgetattr(0, &t_orig);
> >>      t = t_orig;
> >>      cfmakeraw(&t);
> >>      tcsetattr(0, TCSANOW, &t);
> >>      pthread_create(&th, NULL, fwd, f);
> >>      wait(NULL);
> >>      tcsetattr(0, TCSANOW, &t_orig);
> >>      pclose(f);
> >>      return 0;
> >> }
> >>
> > 
> > 
> Thanks Takashi for suggesting many ways to solve this! The C wrapper
> solution looks quite powerful.
> 
> Meanwhile it has occurred to me that bash itself can provide a
> workaround. Since I start the Java console application from a bash
> wrapper already, I have now changed it so that it does something like
> this:
> 
> (while true; do read -s -r -N 1 Key; echo "$Key"; done) | java ...
> 
> With these options to 'read' I get action on every keystroke, and the
> Java program gets its input as terminated length-1 lines.

Another way to do this is:

stty -cooked; cat | java ...

However, this solution and yours need extra key input to quit program
after java program quited.

-- 
Takashi Yano <takashi.yano@nifty.ne.jp>