conspy: new applet
Signed-off-by: Pascal Bellard <pascal.bellard@ads-lu.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Pascal Bellard
Denys Vlasenko
parent
d2b738a6d2
commit
a8b594fda7
472
miscutils/conspy.c
Normal file
472
miscutils/conspy.c
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@ -0,0 +1,472 @@
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/* vi: set sw=4 ts=4: */
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/*
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* A text-mode VNC like program for Linux virtual terminals.
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*
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* pascal.bellard@ads-lu.com
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*
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* Based on Russell Stuart's conspy.c
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* http://ace-host.stuart.id.au/russell/files/conspy.c
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*
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* Licensed under GPLv2 or later, see file License in this tarball for details.
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*
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* example : conspy num shared access to console num
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* or conspy -d num screenshot of console num
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* or conspy -cs num poor man's GNU screen like
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*/
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//applet:IF_CONSPY(APPLET(conspy, _BB_DIR_BIN, _BB_SUID_DROP))
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//kbuild:lib-$(CONFIG_CONSPY) += conspy.o
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//config:config CONSPY
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//config: bool "conspy"
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//config: default n
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//config: help
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//config: A text-mode VNC like program for Linux virtual terminals.
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//config: example : conspy num shared access to console num
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//config: or conspy -d num screenshot of console num
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//config: or conspy -cs num poor man's GNU screen like
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//usage:#define conspy_trivial_usage
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//usage: "[-vcsndf] [-x ROW] [-y LINE] [CONSOLE_NO]"
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//usage:#define conspy_full_usage "\n\n"
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//usage: "A text-mode VNC like program for Linux virtual consoles."
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//usage: "\nTo exit, quickly press ESC 3 times."
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//usage: "\n"
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//usage: "\nOptions:"
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//usage: "\n -v Don't send keystrokes to the console"
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//usage: "\n -c Create missing devices in /dev"
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//usage: "\n -s Open a SHELL session"
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//usage: "\n -n Black & white"
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//usage: "\n -d Dump console to stdout"
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//usage: "\n -f Follow cursor"
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//usage: "\n -x ROW Starting row"
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//usage: "\n -y LINE Starting line"
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#include "libbb.h"
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#include <sys/kd.h>
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struct screen_info {
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unsigned char lines, rows, cursor_x, cursor_y;
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};
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#define CHAR(x) ((x)[0])
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#define ATTR(x) ((x)[1])
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#define NEXT(x) ((x)+=2)
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#define DATA(x) (* (short *) (x))
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struct globals {
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char* data;
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int size;
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int x, y;
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int kbd_fd;
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unsigned width;
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unsigned height;
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char mask;
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char last_attr;
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struct screen_info info;
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struct termios term_orig;
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};
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#define G (*ptr_to_globals)
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#define INIT_G() do { \
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SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
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} while (0)
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static void screen_read_close(int fd, char *data)
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{
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unsigned i, j;
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xread(fd, data, G.size);
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G.last_attr = 0;
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for (i = 0; i < G.info.lines; i++) {
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for (j = 0; j < G.info.rows; j++, NEXT(data)) {
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unsigned x = j - G.x; // if will catch j < G.x too
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unsigned y = i - G.y; // if will catch i < G.y too
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if (CHAR(data) < ' ')
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CHAR(data) = ' ';
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if (y >= G.height || x >= G.width)
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DATA(data) = 0;
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}
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}
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close(fd);
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}
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static void screen_char(char *data)
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{
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if (((G.last_attr - ATTR(data)) & G.mask) != 0) {
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// BLGCRMOW
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static const char color[8] = "04261537";
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printf("\033[%c;4%c;3%cm",
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(ATTR(data) & 8) ? '1' // bold
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: '0', // defaults
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color[(ATTR(data) >> 4) & 7], color[ATTR(data) & 7]);
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G.last_attr = ATTR(data);
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}
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bb_putchar(CHAR(data));
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}
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#define clrscr() printf("\033[1;1H" "\033[0J")
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#define curoff() printf("\033[?25l")
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static void curon(void)
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{
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printf("\033[?25h");
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}
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static void gotoxy(int row, int line)
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{
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printf("\033[%u;%uH", line + 1, row + 1);
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}
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static void screen_dump(char *data)
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{
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int space, linefeed, line, row;
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int linecnt = G.info.lines - G.y;
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data += 2 * G.y * G.info.rows;
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for (linefeed = line = 0; line < linecnt && line < G.height; line++) {
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for (space = row = 0; row < G.info.rows; row++, NEXT(data)) {
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unsigned tty_row = row - G.x; // if will catch row < G.x too
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if (tty_row >= G.width)
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continue;
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space++;
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if (((G.last_attr - ATTR(data)) & G.mask) && CHAR(data) == ' ')
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continue;
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while (linefeed != 0) {
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bb_putchar('\r');
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bb_putchar('\n');
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linefeed--;
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}
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while (--space)
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bb_putchar(' ');
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screen_char(data);
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}
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linefeed++;
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}
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}
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static void curmove(void)
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{
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unsigned cx = G.info.cursor_x - G.x;
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unsigned cy = G.info.cursor_y - G.y;
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if (cx >= G.width || cy >= G.height) {
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curoff();
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} else {
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curon();
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gotoxy(cx, cy);
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}
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fflush_all();
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}
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static void cleanup(int code)
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{
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curon();
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fflush_all();
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tcsetattr(G.kbd_fd, TCSANOW, &G.term_orig);
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if (ENABLE_FEATURE_CLEAN_UP) {
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free(ptr_to_globals);
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close(G.kbd_fd);
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}
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// Reset attributes
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if (G.mask != 0)
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printf("\033[0m");
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bb_putchar('\n');
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if (code > 1)
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kill_myself_with_sig(code); // does not return
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exit(code);
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}
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static void get_initial_data(const char* vcsa_name)
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{
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int size;
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int fd = xopen(vcsa_name, O_RDONLY);
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xread(fd, &G.info, 4);
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G.size = size = G.info.rows * G.info.lines * 2;
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G.width = G.height = UINT_MAX;
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G.data = xzalloc(2 * size);
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screen_read_close(fd, G.data);
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}
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static void create_cdev_if_doesnt_exist(const char* name, dev_t dev)
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{
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int fd = open(name, O_RDONLY);
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if (fd != -1)
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close(fd);
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else if (errno == ENOENT)
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mknod(name, S_IFCHR | 0660, dev);
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}
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static NOINLINE void start_shell_in_child(const char* tty_name)
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{
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int pid = vfork();
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if (pid < 0) {
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bb_perror_msg_and_die("vfork");
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}
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if (pid == 0) {
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struct termios termchild;
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char *shell = getenv("SHELL");
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if (!shell)
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shell = (char *) DEFAULT_SHELL;
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signal(SIGHUP, SIG_IGN);
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// set tty as a controlling tty
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setsid();
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// make tty to be input, output, error
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close(0);
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xopen(tty_name, O_RDWR); // uses fd 0
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xdup2(0, 1);
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xdup2(0, 2);
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ioctl(0, TIOCSCTTY, 1);
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tcsetpgrp(0, getpid());
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tcgetattr(0, &termchild);
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termchild.c_lflag |= ECHO;
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termchild.c_oflag |= ONLCR | XTABS;
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termchild.c_iflag |= ICRNL;
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termchild.c_iflag &= ~IXOFF;
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tcsetattr_stdin_TCSANOW(&termchild);
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execl(shell, shell, "-i", (char *) NULL);
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bb_simple_perror_msg_and_die(shell);
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}
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}
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enum {
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FLAG_v, // view only
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FLAG_c, // create device if need
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FLAG_s, // session
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FLAG_n, // no colors
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FLAG_d, // dump screen
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FLAG_f, // follow cursor
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};
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#define FLAG(x) (1 << FLAG_##x)
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int conspy_main(int argc UNUSED_PARAM, char **argv) MAIN_EXTERNALLY_VISIBLE;
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int conspy_main(int argc UNUSED_PARAM, char **argv)
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{
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char *buffer[2];
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char vcsa_name[sizeof("/dev/vcsa") + 2];
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char tty_name[sizeof("/dev/tty") + 2];
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#define keybuf bb_common_bufsiz1
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struct termios termbuf;
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unsigned opts;
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unsigned ttynum;
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int poll_timeout_ms;
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int current;
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int ioerror_count;
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int key_count;
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int escape_count;
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int nokeys;
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#if ENABLE_LONG_OPTS
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static const char getopt_longopts[] ALIGN1 =
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"viewonly\0" No_argument "v"
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"createdevice\0" No_argument "c"
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"session\0" No_argument "s"
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"nocolors\0" No_argument "n"
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"dump\0" No_argument "d"
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"follow\0" No_argument "f"
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;
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applet_long_options = getopt_longopts;
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#endif
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INIT_G();
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strcpy(vcsa_name, "/dev/vcsa");
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opt_complementary = "x+:y+"; // numeric params
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opts = getopt32(argv, "vcsndfx:y:", &G.x, &G.y);
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argv += optind;
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ttynum = 0;
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if (argv[0]) {
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ttynum = xatou_range(argv[0], 0, 63);
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sprintf(vcsa_name + sizeof("/dev/vcsa")-1, "%u", ttynum);
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}
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sprintf(tty_name, "%s%u", "/dev/tty", ttynum);
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if (!(opts & FLAG(n)))
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G.mask = 0xff;
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if (opts & FLAG(c)) {
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if ((opts & (FLAG(s)|FLAG(v))) != FLAG(v))
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create_cdev_if_doesnt_exist(tty_name, makedev(4, ttynum));
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create_cdev_if_doesnt_exist(vcsa_name, makedev(7, 128 + ttynum));
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}
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if ((opts & FLAG(s)) && ttynum) {
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start_shell_in_child(tty_name);
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}
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get_initial_data(vcsa_name);
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G.kbd_fd = xopen(CURRENT_TTY, O_RDONLY);
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if (opts & FLAG(d)) {
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screen_dump(G.data);
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bb_putchar('\n');
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if (ENABLE_FEATURE_CLEAN_UP) {
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free(ptr_to_globals);
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close(G.kbd_fd);
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}
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return 0;
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}
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bb_signals(BB_FATAL_SIGS, cleanup);
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// All characters must be passed through to us unaltered
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tcgetattr(G.kbd_fd, &G.term_orig);
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termbuf = G.term_orig;
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termbuf.c_iflag &= ~(BRKINT|INLCR|ICRNL|IXON|IXOFF|IUCLC|IXANY|IMAXBEL);
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termbuf.c_oflag &= ~(OPOST);
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termbuf.c_lflag &= ~(ISIG|ICANON|ECHO);
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termbuf.c_cc[VMIN] = 1;
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termbuf.c_cc[VTIME] = 0;
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tcsetattr(G.kbd_fd, TCSANOW, &termbuf);
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buffer[0] = G.data;
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buffer[1] = G.data + G.size;
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poll_timeout_ms = 250;
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ioerror_count = key_count = escape_count = nokeys = current = 0;
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while (1) {
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struct pollfd pfd;
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int vcsa_handle;
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int bytes_read;
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int i, j;
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int next = 1 - current;
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char *data = buffer[next];
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char *old = buffer[current];
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// Close & re-open vcsa in case they have
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// swapped virtual consoles
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vcsa_handle = xopen(vcsa_name, O_RDONLY);
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xread(vcsa_handle, &G.info, 4);
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if (G.size != (G.info.rows * G.info.lines * 2)) {
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cleanup(1);
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}
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i = G.width;
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j = G.height;
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get_terminal_width_height(G.kbd_fd, &G.width, &G.height);
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if ((option_mask32 & FLAG(f))) {
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int nx = G.info.cursor_x - G.width + 1;
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int ny = G.info.cursor_y - G.height + 1;
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if (G.info.cursor_x < G.x) {
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G.x = G.info.cursor_x;
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i = 0; // force refresh
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}
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if (nx > G.x) {
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G.x = nx;
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i = 0; // force refresh
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}
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if (G.info.cursor_y < G.y) {
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G.y = G.info.cursor_y;
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i = 0; // force refresh
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}
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if (ny > G.y) {
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G.y = ny;
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i = 0; // force refresh
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}
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}
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// Scan console data and redraw our tty where needed
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screen_read_close(vcsa_handle, data);
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if (i != G.width || j != G.height) {
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clrscr();
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screen_dump(data);
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}
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else for (i = 0; i < G.info.lines; i++) {
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char *last = last;
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char *first = NULL;
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int iy = i - G.y;
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if (iy >= (int) G.height)
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break;
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for (j = 0; j < G.info.rows; j++) {
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last = data;
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if (DATA(data) != DATA(old) && iy >= 0) {
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unsigned jx = j - G.x;
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last = NULL;
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if (first == NULL && jx < G.width) {
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first = data;
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gotoxy(jx, iy);
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}
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}
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NEXT(old);
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NEXT(data);
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}
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if (first == NULL)
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continue;
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if (last == NULL)
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last = data;
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// Write the data to the screen
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for (; first < last; NEXT(first))
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screen_char(first);
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}
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current = next;
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curmove();
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// Wait for local user keypresses
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pfd.fd = G.kbd_fd;
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pfd.events = POLLIN;
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bytes_read = 0;
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switch (poll(&pfd, 1, poll_timeout_ms)) {
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case -1:
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if (errno != EINTR)
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cleanup(1);
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break;
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case 0:
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if (++nokeys >= 4)
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nokeys = escape_count = 0;
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break;
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default:
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// Read the keys pressed
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bytes_read = read(G.kbd_fd, keybuf + key_count,
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sizeof(keybuf) - key_count);
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if (bytes_read < 0)
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cleanup(1);
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// Do exit processing
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for (i = 0; i < bytes_read; i++) {
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if (keybuf[key_count + i] != '\033')
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escape_count = 0;
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else if (++escape_count >= 3)
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cleanup(0);
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}
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}
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poll_timeout_ms = 250;
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// Insert all keys pressed into the virtual console's input
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// buffer. Don't do this if the virtual console is in scan
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// code mode - giving ASCII characters to a program expecting
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// scan codes will confuse it.
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if (!(option_mask32 & FLAG(v)) && escape_count == 0) {
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int handle, result;
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long kbd_mode;
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key_count += bytes_read;
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handle = xopen(tty_name, O_WRONLY);
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result = ioctl(handle, KDGKBMODE, &kbd_mode);
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if (result == -1)
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/* nothing */;
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else if (kbd_mode != K_XLATE && kbd_mode != K_UNICODE)
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key_count = 0; // scan code mode
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else {
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for (i = 0; i < key_count && result != -1; i++)
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result = ioctl(handle, TIOCSTI, keybuf + i);
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key_count -= i;
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if (key_count)
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memmove(keybuf, keybuf + i, key_count);
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// If there is an application on console which reacts
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// to keypresses, we need to make our first sleep
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// shorter to quickly redraw whatever it printed there.
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poll_timeout_ms = 20;
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}
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// Close & re-open tty in case they have
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// swapped virtual consoles
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close(handle);
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||||
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||||
// We sometimes get spurious IO errors on the TTY
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// as programs close and re-open it
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if (result != -1)
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ioerror_count = 0;
|
||||
else if (errno != EIO || ++ioerror_count > 4)
|
||||
cleanup(1);
|
||||
}
|
||||
}
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user