all repos — xyw @ 997e522eaeebf929ad5387a964ba611d287b1923

A minimal virtual machine and assembler for terminals.

devices/terminal.c

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#include <stdio.h>
#include "../xyw.h"

#ifndef _WIN32
#include <termios.h>
#include <unistd.h>

static struct termios terminal_orig_termios;
static int terminal_raw_mode_active = 0;
#endif

/* terminal device */
#define TERMINAL_INPUT 0x0
#define TERMINAL_OUTPUT 0x1
#define TERMINAL_ON_KEYPRESS 0x2
#define TERMINAL_ON_ARGUMENT 0x4

void terminal_init(xyw_byte *data)
{
    (void)data;
#ifndef _WIN32
    struct termios raw;

    if (!isatty(STDIN_FILENO))
    {
        // Not a real terminal (e.g. piped input/tests) — nothing to save or set
        return;
    }

    if (tcgetattr(STDIN_FILENO, &terminal_orig_termios) != 0)
    {
        XYW_DBG("terminal: tcgetattr failed, raw mode not enabled\n");
        return;
    }

    raw = terminal_orig_termios;
    raw.c_lflag &= ~(ICANON | ECHO | ISIG);
    // Read returns as soon as 1 byte is available, no inter-byte timeout
    raw.c_cc[VMIN] = 1;
    raw.c_cc[VTIME] = 0;

    if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &raw) != 0)
    {
        XYW_DBG("terminal: tcsetattr failed, raw mode not enabled\n");
        return;
    }

    terminal_raw_mode_active = 1;
#endif
}

void terminal_teardown(xyw_byte *data)
{
    (void)data;
#ifndef _WIN32
    if (terminal_raw_mode_active)
    {
        tcsetattr(STDIN_FILENO, TCSAFLUSH, &terminal_orig_termios);
        terminal_raw_mode_active = 0;
    }
#endif
}

void terminal_output(xyw_byte *data, xyw_byte addr, xyw_byte *error)
{
    (void)error;
    switch (addr)
    {
    case TERMINAL_INPUT:
    {
        xyw_word handler;
        if (!xyw_argv_processed && XYW_PEEKW(&data[TERMINAL_ON_ARGUMENT]))
        {
            // Process input as arguments (separated by XYW_ARGUMENT_SEPARATOR) until XYW_END_OF_ARGUMENTS
            handler = XYW_PEEKW(&data[TERMINAL_ON_ARGUMENT]);
        }
        else
        {
            // Process stdin keypress
            handler = XYW_PEEKW(&data[TERMINAL_ON_KEYPRESS]);
        }
        if (handler)
        {
            xyw_eval(handler);
        }
        break;
    }
    case TERMINAL_OUTPUT:
        fputc(data[addr], stdout);
        fflush(stdout);
        break;
    }
}

xyw_byte terminal_input(xyw_byte *data, xyw_byte addr, xyw_byte *error)
{
    (void)error;
    return data[addr];
}