mirror of
https://github.com/sheumann/hush.git
synced 2024-08-20 19:29:02 +00:00
libbb: add forgotten file from previous commit :(
This commit is contained in:
parent
0112ff5203
commit
39b0135c59
146
libbb/read_key.c
Normal file
146
libbb/read_key.c
Normal file
@ -0,0 +1,146 @@
|
||||
/* vi: set sw=4 ts=4: */
|
||||
/*
|
||||
* Utility routines.
|
||||
*
|
||||
* Copyright (C) 2008 Denys Vlasenko
|
||||
*
|
||||
* Licensed under GPL version 2, see file LICENSE in this tarball for details.
|
||||
*/
|
||||
#include "libbb.h"
|
||||
|
||||
int FAST_FUNC read_key(int fd, smalluint *nbuffered, char *buffer)
|
||||
{
|
||||
struct pollfd pfd;
|
||||
const char *seq;
|
||||
int n;
|
||||
int c;
|
||||
|
||||
/* Known escape sequences for cursor and function keys */
|
||||
static const char esccmds[] ALIGN1 = {
|
||||
'O','A' |0x80,KEYCODE_UP ,
|
||||
'O','B' |0x80,KEYCODE_DOWN ,
|
||||
'O','C' |0x80,KEYCODE_RIGHT ,
|
||||
'O','D' |0x80,KEYCODE_LEFT ,
|
||||
'O','H' |0x80,KEYCODE_HOME ,
|
||||
'O','F' |0x80,KEYCODE_END ,
|
||||
#if 0
|
||||
'O','P' |0x80,KEYCODE_FUN1 ,
|
||||
'O','Q' |0x80,KEYCODE_FUN2 ,
|
||||
'O','R' |0x80,KEYCODE_FUN3 ,
|
||||
'O','S' |0x80,KEYCODE_FUN4 ,
|
||||
#endif
|
||||
'[','A' |0x80,KEYCODE_UP ,
|
||||
'[','B' |0x80,KEYCODE_DOWN ,
|
||||
'[','C' |0x80,KEYCODE_RIGHT ,
|
||||
'[','D' |0x80,KEYCODE_LEFT ,
|
||||
'[','H' |0x80,KEYCODE_HOME ,
|
||||
'[','F' |0x80,KEYCODE_END ,
|
||||
'[','1','~' |0x80,KEYCODE_HOME ,
|
||||
'[','2','~' |0x80,KEYCODE_INSERT ,
|
||||
'[','3','~' |0x80,KEYCODE_DELETE ,
|
||||
'[','4','~' |0x80,KEYCODE_END ,
|
||||
'[','5','~' |0x80,KEYCODE_PAGEUP ,
|
||||
'[','6','~' |0x80,KEYCODE_PAGEDOWN,
|
||||
#if 0
|
||||
'[','1','1','~'|0x80,KEYCODE_FUN1 ,
|
||||
'[','1','2','~'|0x80,KEYCODE_FUN2 ,
|
||||
'[','1','3','~'|0x80,KEYCODE_FUN3 ,
|
||||
'[','1','4','~'|0x80,KEYCODE_FUN4 ,
|
||||
'[','1','5','~'|0x80,KEYCODE_FUN5 ,
|
||||
'[','1','7','~'|0x80,KEYCODE_FUN6 ,
|
||||
'[','1','8','~'|0x80,KEYCODE_FUN7 ,
|
||||
'[','1','9','~'|0x80,KEYCODE_FUN8 ,
|
||||
'[','2','0','~'|0x80,KEYCODE_FUN9 ,
|
||||
'[','2','1','~'|0x80,KEYCODE_FUN10 ,
|
||||
'[','2','3','~'|0x80,KEYCODE_FUN11 ,
|
||||
'[','2','4','~'|0x80,KEYCODE_FUN12 ,
|
||||
#endif
|
||||
0
|
||||
};
|
||||
|
||||
n = *nbuffered;
|
||||
if (n == 0) {
|
||||
/* If no data, block waiting for input. If we read more
|
||||
* than the minimal ESC sequence size, the "n=0" below
|
||||
* would instead have to figure out how much to keep,
|
||||
* resulting in larger code. */
|
||||
n = safe_read(fd, buffer, 3);
|
||||
if (n <= 0)
|
||||
return -1;
|
||||
}
|
||||
|
||||
/* Grab character to return from buffer */
|
||||
c = (unsigned char)buffer[0];
|
||||
n--;
|
||||
if (n)
|
||||
memmove(buffer, buffer + 1, n);
|
||||
|
||||
/* Only ESC starts ESC sequences */
|
||||
if (c != 27)
|
||||
goto ret;
|
||||
|
||||
/* Loop through known ESC sequences */
|
||||
pfd.fd = fd;
|
||||
pfd.events = POLLIN;
|
||||
seq = esccmds;
|
||||
while (*seq != '\0') {
|
||||
/* n - position in sequence we did not read yet */
|
||||
int i = 0; /* position in sequence to compare */
|
||||
|
||||
/* Loop through chars in this sequence */
|
||||
while (1) {
|
||||
/* So far escape sequence matched up to [i-1] */
|
||||
if (n <= i) {
|
||||
/* Need more chars, read another one if it wouldn't block.
|
||||
* Note that escape sequences come in as a unit,
|
||||
* so if we block for long it's not really an escape sequence.
|
||||
* Timeout is needed to reconnect escape sequences
|
||||
* split up by transmission over a serial console. */
|
||||
if (safe_poll(&pfd, 1, 50) == 0) {
|
||||
/* No more data!
|
||||
* Array is sorted from shortest to longest,
|
||||
* we can't match anything later in array,
|
||||
* break out of both loops. */
|
||||
goto ret;
|
||||
}
|
||||
errno = 0;
|
||||
if (safe_read(fd, buffer + n, 1) <= 0) {
|
||||
/* If EAGAIN, then fd is O_NONBLOCK and poll lied:
|
||||
* in fact, there is no data. */
|
||||
if (errno != EAGAIN)
|
||||
c = -1; /* otherwise it's EOF/error */
|
||||
goto ret;
|
||||
}
|
||||
n++;
|
||||
}
|
||||
if (buffer[i] != (seq[i] & 0x7f)) {
|
||||
/* This seq doesn't match, go to next */
|
||||
seq += i;
|
||||
/* Forward to last char */
|
||||
while (!(*seq & 0x80))
|
||||
seq++;
|
||||
/* Skip it and the keycode which follows */
|
||||
seq += 2;
|
||||
break;
|
||||
}
|
||||
if (seq[i] & 0x80) {
|
||||
/* Entire seq matched */
|
||||
c = (signed char)seq[i+1];
|
||||
n = 0;
|
||||
/* n -= i; memmove(...);
|
||||
* would be more correct,
|
||||
* but we never read ahead that much,
|
||||
* and n == i here. */
|
||||
goto ret;
|
||||
}
|
||||
i++;
|
||||
}
|
||||
}
|
||||
/* We did not find matching sequence, it was a bare ESC.
|
||||
* We possibly read and stored more input in buffer[]
|
||||
* by now. */
|
||||
|
||||
ret:
|
||||
*nbuffered = n;
|
||||
return c;
|
||||
}
|
Loading…
Reference in New Issue
Block a user