cosmopolitan/libc/log/restoretty.c

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2021 Justine Alexandra Roberts Tunney                              │
│                                                                              │
│ Permission to use, copy, modify, and/or distribute this software for         │
│ any purpose with or without fee is hereby granted, provided that the         │
│ above copyright notice and this permission notice appear in all copies.      │
│                                                                              │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
│ PERFORMANCE OF THIS SOFTWARE.                                                │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/calls/calls.h"
#include "libc/calls/struct/termios.h"
#include "libc/calls/termios.h"
#include "libc/errno.h"
#include "libc/log/color.internal.h"
#include "libc/log/internal.h"
#include "libc/runtime/internal.h"
#include "libc/sysv/consts/termios.h"

/**
 * @fileoverview Terminal Restoration Helper
 *
 * This is used by the crash reporting functions, e.g. __die(), to help
 * ensure the terminal is in an unborked state after a crash happens.
 */

#define RESET_COLOR   "\e[0m"
#define SHOW_CURSOR   "\e[?25h"
#define DISABLE_MOUSE "\e[?1000;1002;1015;1006l"
#define ANSI_RESTORE  RESET_COLOR SHOW_CURSOR DISABLE_MOUSE

struct termios g_oldtermios;

static textstartup void g_oldtermios_init() {
  int e = errno;
  tcgetattr(1, &g_oldtermios);
  errno = e;
}

const void *const g_oldtermios_ctor[] initarray = {
    g_oldtermios_init,
};

void __restore_tty(int fd) {
  int e;
  if (!__isworker) {
    e = errno;
    if (g_oldtermios.c_lflag && !__nocolor && isatty(fd)) {
      write(fd, ANSI_RESTORE, strlen(ANSI_RESTORE));
      tcsetattr(fd, TCSAFLUSH, &g_oldtermios);
    }
    errno = e;
  }
}