gno/bin/less/ttyin.c

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/*
* Routines dealing with getting input from the keyboard (i.e. from the user).
*/
#pragma noroot
#include "less.h"
#include <fcntl.h>
#include <stdio.h>
#if __MSDOS__
#include <io.h>
#include <stdio.h>
#include <fcntl.h>
#include <signal.h>
#endif
#ifdef _ORCAC_
segment "LoadSegONE";
#endif
static int tty;
/*
* Open keyboard for input.
*/
public void
open_getchr(void)
{
#if __MDDOS__
/*
* Open a new handle to CON: in binary mode
* for unbuffered keyboard read.
*/
tty = open("CON", O_RDONLY|O_BINARY);
#else
/*
* Try /dev/tty.
* If that doesn't work, use file descriptor 2,
* which in Unix is usually attached to the screen,
* but also usually lets you read from the keyboard.
*/
tty = open(".tty", O_RDWR);
if (tty < 0)
tty = 2;
#endif
}
/*
* Get a character from the keyboard.
*/
public int
getchr(void)
{
char c;
int result;
do
{
result = iread(tty, &c, sizeof(char));
if (result == READ_INTR)
return (READ_INTR);
if (result < 0)
{
/*
* Don't call error() here,
* because error calls getchr!
*/
quit(1);
}
#if __MSDOS__
/*
* In raw read, we don't see ^C so look here for it.
*/
if (c == '\003')
raise(SIGINT);
#endif
/*
* Various parts of the program cannot handle
* an input character of '\0'.
* If a '\0' was actually typed, convert it to '\200' here.
*/
if (c == '\0')
c = '\200';
} while (result != 1);
return (c);
}