Hello,

I'm following this tutorial and I'm having some trouble setting the flags.

I have this C program that works properly (exits as soon as I press q and CTRL+C does not kill it).

#include <stdlib.h>
#include <ctype.h>
#include <stdio.h>
#include <termios.h>
#include <unistd.h>

struct termios orig_termios;

void disableRawMode() {
  tcsetattr(STDIN_FILENO, TCSAFLUSH, &orig_termios);
}

void enableRawMode() {
  tcgetattr(STDIN_FILENO, &orig_termios);
  atexit(disableRawMode);
  struct termios raw = orig_termios;
  raw.c_lflag &= ~(ECHO | ICANON | ISIG);
  tcsetattr(STDIN_FILENO, TCSAFLUSH, &raw);
}

int main() {

  enableRawMode();

  char c;
  while (read(STDIN_FILENO, &c, 1) == 1 && c != 'q') {
    if (iscntrl(c)) {
      printf("%d\n", c);
    } else {
      printf("%d ('%c')\n", c, c);
    }
  }

  return 0;
}

I'm trying to write the equivalent program in D.

source/app.d

import adapter;
import core.stdc.stdlib : atexit;
import core.stdc.stdio : printf;
import core.stdc.ctype : iscntrl;

termios orig_termios;

extern (C)
{
	void disableRawMode() {
		tcsetattr(STDIN_FILENO, TCSANOW, &orig_termios);
	}
}

void enableRawMode() {
	tcgetattr(STDIN_FILENO, &orig_termios);
	atexit(&disableRawMode);

	termios raw = orig_termios;
	// TODO flags ICANON and ISIG do not work
	raw.c_lflag &= ~(ECHO | ICANON | ISIG);

	tcsetattr(STDIN_FILENO, TCSANOW, &raw);
}

int main()
{
	enableRawMode();

	char c;
	while (read(STDIN_FILENO, &c, 1) == 1 && c != 'q') {
		if (iscntrl(c)) {
			printf("%d\n", c);
		} else {
			printf("%d ('%c')\n", c, c);
		}
	}

	return 0;
}

source/adapter/package.d

module adapter;

public import adapter.termios;
public import adapter.unistd;

source/adapter/termios.d

module adapter.termios;

import std.typecons : Typedef;

// from termios.h, https://github.com/openbsd/src/blob/master/sys/sys/termios.h
enum int ECHO   = 0x00000008;
enum int ICANON = 0x00000100;
enum int ISIG   = 0x00000080;

enum int IXON   = 0x00000200;
enum int IEXTEN = 0x00000400;
enum int ICRNL  = 0x00000100;

enum int TCSANOW = 0;
enum int TCSADRAIN = 1;
enum int TCSAFLUSH = 2;

enum int NCCS = 20;

alias tcflag_t = Typedef!uint;
alias cc_t = Typedef!ubyte;
// alias speed_t = Typedef!uint;

struct termios {
	tcflag_t c_iflag;	/* input flags */
	tcflag_t c_oflag;	/* output flags */
	tcflag_t c_cflag;	/* control flags */
	tcflag_t c_lflag;	/* local flags */
	cc_t[NCCS] c_cc;	/* control chars */
	int c_ispeed;	/* input speed */
	int c_ospeed;	/* output speed */
};

extern (C) int tcgetattr(int, termios *);
extern (C) int tcsetattr(int, int, const termios *);

source/adapter/unistd.d

module adapter.unistd;

import core.sys.posix.sys.types : ssize_t;

// TODO fix import
enum int STDIN_FILENO = 0;
// import core.stdc.stdio : STDIN_FILENO;

// from unistd.h
extern (C) ssize_t read(int fildes, void *buf, size_t nbytes);

When I try to run it with dub run the only flag that appears to be set is ~(ECHO). It does exit when I press CTRL+C and it does not exit as soon as I press q, I must follow that with an ENTER.

Is there a better way to use termios.h inside D? Am I missing the point and there is a way to set these flags in D without using C libraries?

On Tuesday, 29 August 2023 at 16:17:56 UTC, Răzvan Birișan wrote:

I would try to use termios from druntime instead.

Try: import core.sys.posix.termios;

On Tuesday, 29 August 2023 at 16:59:57 UTC, Dejan Lekic wrote:

I've made the change and that fixed the issue. Looks like there is also core.sys.posix.unistd, I'll use this and remove the C bindings that I've created.

I was only searching the official documentation and "termios" returned 0 results.
I also stumbled upon the unofficial documentation but didn't find it useful.

I now realize the I can browse the dmd source code on github...