usr.bin/bc/tty.c

   1 /*      $OpenBSD: tty.c,v 1.1 2013/09/19 16:12:01 otto Exp $    */
   2
   3 /*
   4  * Copyright (c) 2013, Otto Moerbeek <otto@drijf.net>
   5  *
   6  * Permission to use, copy, modify, and distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 #include <errno.h>
  20 #include <signal.h>
  21 #include <histedit.h>
  22 #include <termios.h>
  23 #include "extern.h"
  24
  25 struct termios ttysaved, ttyedit;
  26
  27 static int settty(struct termios *);
  28
  29 static int
  30 settty(struct termios *t)
  31 {
  32         int ret;
  33
  34         while ((ret = tcsetattr(0, TCSADRAIN,  t)) == -1 && errno == EINTR)
  35                 continue;
  36         return ret;
  37 }
  38
  39 int
  40 gettty(struct termios *t)
  41 {
  42         int ret;
  43
  44         while ((ret = tcgetattr(0, t) == -1) && errno == EINTR)
  45                 continue;
  46         return ret;
  47 }
  48
  49 /* ARGSUSED */
  50 void
  51 tstpcont(int sig)
  52 {
  53         int save_errno = errno;
  54
  55         if (sig == SIGTSTP) {
  56                 signal(SIGCONT, tstpcont);
  57                 gettty(&ttyedit);
  58                 settty(&ttysaved);
  59         } else {
  60                 signal(SIGTSTP, tstpcont);
  61                 settty(&ttyedit);
  62         }
  63         signal(sig, SIG_DFL);
  64         kill(0, sig);
  65         errno = save_errno;
  66 }