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ben-wpan/tools/lib/getkey.c
Werner Almesberger 56f8b2d038 tools/: moved get_key from atrf-path/gui.c to libatrf, for sharing
The old "raw" function becomes get_key_init. Calling get_key_init is
only necessary if one wants to control the moment standard input is
switched to raw mode. If get_key is invoked without a prior call to
get_key_init, it will initialize automatically.

- atrf-path/gui.c (raw, main): renamed "raw" to get_key_init
- atrf-path/gui.c (old_term, restore_term, get_key_init, get_key):
  moved to include/getkey.h and lib/getkey.c
- lib/getkey.c (get_key_init, get_key): made calling get_key_init
  optional
- lib/Makefile (OBJS): added getkey.o
2011-07-04 20:29:22 -03:00

79 lines
1.3 KiB
C

/*
* lib/getkey.c - Get single characters from standard input
*
* Written 2011 by Werner Almesberger
* Copyright 2011 Werner Almesberger
*
* 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; either version 2 of the License, or
* (at your option) any later version.
*/
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <termios.h>
#include <errno.h>
static struct termios old_term;
static void restore_term(void)
{
if (tcsetattr(0, TCSAFLUSH, &old_term) < 0)
perror("tcsetattr");
}
void get_key_init(void)
{
static int initialized = 0;
struct termios term;
if (initialized)
return;
initialized = 1;
if (tcgetattr(0, &old_term) < 0) {
perror("tcgetattr");
exit(1);
}
term = old_term;
cfmakeraw(&term);
if (tcsetattr(0, TCSAFLUSH, &term) < 0) {
perror("tcsetattr");
exit(1);
}
atexit(restore_term);
if (fcntl(0, F_SETFL, O_NONBLOCK) < 0) {
perror("fcntl");
exit(1);
}
}
char get_key(void)
{
ssize_t got;
char ch;
get_key_init();
got = read(0, &ch, 1);
if (got == 1)
return ch;
if (got >= 0) {
fprintf(stderr, "unexpected read() return value %d\n",
(int) got);
exit(1);
}
if (errno == EAGAIN)
return 0;
perror("read");
exit(1);
}