cosmopolitan/dsp/tty/config.c

47 lines
2.6 KiB
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 2020 Justine Alexandra Roberts Tunney │
│ │
│ This program is free software; you can redistribute it and/or modify │
│ it under the terms of the GNU General Public License as published by │
│ the Free Software Foundation; version 2 of the License. │
│ │
│ This program is distributed in the hope that it will be useful, but │
│ WITHOUT ANY WARRANTY; without even the implied warranty of │
│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
│ General Public License for more details. │
│ │
│ You should have received a copy of the GNU General Public License │
│ along with this program; if not, write to the Free Software │
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
│ 02110-1301 USA │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "dsp/tty/tty.h"
#include "libc/assert.h"
#include "libc/calls/termios.h"
#include "libc/str/str.h"
#include "libc/sysv/consts/termios.h"
/**
* Applies configuration to teletypewriter.
*
* @param opt_out_oldconf is only modified if successful
* @return 0 on success, or -1 w/ errno
* @see ttyconfig(), ttyrestore()
*/
int ttyconfig(int ttyfd, ttyconf_f fn, int64_t arg,
const struct termios *opt_out_oldconf) {
struct termios conf[2];
if (tcgetattr(ttyfd, &conf[0]) != -1 &&
fn(memcpy(&conf[1], &conf[0], sizeof(conf[0])), arg) != -1 &&
tcsetattr(ttyfd, TCSAFLUSH, &conf[1]) != -1) {
if (opt_out_oldconf) {
memcpy(opt_out_oldconf, &conf[0], sizeof(conf[0]));
}
return 0;
} else {
return -1;
}
}