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/*
* Copyright (c) 2011-2013 Kevin Lange. All rights reserved.
*
* Developed by: Kevin Lange
* http://github.com/klange/nyancat
* http://nyancat.dakko.us
*
* 40-column support by: Peter Hazenberg
* http://github.com/Peetz0r/nyancat
* http://peter.haas-en-berg.nl
*
* Build tools unified by: Aaron Peschel
* https://github.com/apeschel
*
* For a complete listing of contributers, please see the git commit history.
*
* This is a simple telnet server / standalone application which renders the
* classic Nyan Cat (or "poptart cat") to your terminal.
*
* It makes use of various ANSI escape sequences to render color, or in the case
* of a VT220, simply dumps text to the screen.
*
* For more information, please see:
*
* http://nyancat.dakko.us
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to
* deal with the Software without restriction, including without limitation the
* rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
* sell copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimers.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimers in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the names of the Association for Computing Machinery, Kevin
* Lange, nor the names of its contributors may be used to endorse
* or promote products derived from this Software without specific prior
* written permission.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* CONTRIBUTORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* WITH THE SOFTWARE.
*/
#define _XOPEN_SOURCE 500
#include <ctype.h>
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <signal.h>
#include <time.h>
#include <setjmp.h>
#include <getopt.h>
#include <sys/ioctl.h>
#ifndef TIOCGWINSZ
#include <termios.h>
#endif
#ifdef ECHO
#undef ECHO
#endif
/*
* telnet.h contains some #defines for the various
* commands, escape characters, and modes for telnet.
* (it surprises some people that telnet is, really,
* a protocol, and not just raw text transmission)
*/
#include "telnet.h"
/*
* The animation frames are stored separately in
* this header so they don't clutter the core source
*/
#include "animation.h"
/*
* Color palette to use for final output
* Specifically, this should be either control sequences
* or raw characters (ie, for vt220 mode)
*/
const char * colors[256] = {NULL};
/*
* For most modes, we output spaces, but for some
* we will use block characters (or even nothing)
*/
const char * output = " ";
/*
* Are we currently in telnet mode?
*/
int telnet = 0;
/*
* Whether or not to show the counter
*/
int show_counter = 1;
/*
* Number of frames to show before quitting
* or 0 to repeat forever (default)
*/
unsigned int frame_count = 0;
/*
* Clear the screen between frames (as opposed to reseting
* the cursor position)
*/
int clear_screen = 1;
/*
* Force-set the terminal title.
*/
int set_title = 1;
/*
* Environment to use for setjmp/longjmp
* when breaking out of options handler
*/
jmp_buf environment;
/*
* I refuse to include libm to keep this low
* on external dependencies.
*
* Count the number of digits in a number for
* use with string output.
*/
int digits(int val) {
int d = 1, c;
if (val >= 0) for (c = 10; c <= val; c *= 10) d++;
else for (c = -10 ; c >= val; c *= 10) d++;
return (c < 0) ? ++d : d;
}
/*
* These values crop the animation, as we have a full 64x64 stored,
* but we only want to display 40x24 (double width).
*/
int min_row = -1;
int max_row = -1;
int min_col = -1;
int max_col = -1;
/*
* Actual width/height of terminal.
*/
int terminal_width = 80;
int terminal_height = 24;
/*
* Flags to keep track of whether width/height were automatically set.
*/
char using_automatic_width = 0;
char using_automatic_height = 0;
/*
* Print escape sequences to return cursor to visible mode
* and exit the application.
*/
void finish() {
if (clear_screen) {
printf("\033[?25h\033[0m\033[H\033[2J");
} else {
printf("\033[0m\n");
}
exit(0);
}
/*
* In the standalone mode, we want to handle an interrupt signal
* (^C) so that we can restore the cursor and clear the terminal.
*/
void SIGINT_handler(int sig){
(void)sig;
finish();
}
/*
* Handle the alarm which breaks us off of options
* handling if we didn't receive a terminal
*/
void SIGALRM_handler(int sig) {
(void)sig;
alarm(0);
longjmp(environment, 1);
/* Unreachable */
}
/*
* Handle the loss of stdout, as would be the case when
* in telnet mode and the client disconnects
*/
void SIGPIPE_handler(int sig) {
(void)sig;
finish();
}
void SIGWINCH_handler(int sig) {
(void)sig;
struct winsize w;
ioctl(0, TIOCGWINSZ, &w);
terminal_width = w.ws_col;
terminal_height = w.ws_row;
if (using_automatic_width) {
min_col = (FRAME_WIDTH - terminal_width/2) / 2;
max_col = (FRAME_WIDTH + terminal_width/2) / 2;
}
if (using_automatic_height) {
min_row = (FRAME_HEIGHT - (terminal_height-1)) / 2;
max_row = (FRAME_HEIGHT + (terminal_height-1)) / 2;
}
signal(SIGWINCH, SIGWINCH_handler);
}
/*
* Telnet requires us to send a specific sequence
* for a line break (\r\000\n), so let's make it happy.
*/
void newline(int n) {
int i = 0;
for (i = 0; i < n; ++i) {
/* We will send `n` linefeeds to the client */
if (telnet) {
/* Send the telnet newline sequence */
putc('\r', stdout);
putc(0, stdout);
putc('\n', stdout);
} else {
/* Send a regular line feed */
putc('\n', stdout);
}
}
}
/*
* These are the options we want to use as
* a telnet server. These are set in set_options()
*/
unsigned char telnet_options[256] = { 0 };
unsigned char telnet_willack[256] = { 0 };
/*
* These are the values we have set or
* agreed to during our handshake.
* These are set in send_command(...)
*/
unsigned char telnet_do_set[256] = { 0 };
unsigned char telnet_will_set[256]= { 0 };
/*
* Set the default options for the telnet server.
*/
void set_options() {
/* We will not echo input */
telnet_options[ECHO] = WONT;
/* We will set graphics modes */
telnet_options[SGA] = WILL;
/* We will not set new environments */
telnet_options[NEW_ENVIRON] = WONT;
/* The client should echo its own input */
telnet_willack[ECHO] = DO;
/* The client can set a graphics mode */
telnet_willack[SGA] = DO;
/* The client should not change, but it should tell us its window size */
telnet_willack[NAWS] = DO;
/* The client should tell us its terminal type (very important) */
telnet_willack[TTYPE] = DO;
/* No linemode */
telnet_willack[LINEMODE] = DONT;
/* And the client can set a new environment */
telnet_willack[NEW_ENVIRON] = DO;
}
/*
* Send a command (cmd) to the telnet client
* Also does special handling for DO/DONT/WILL/WONT
*/
void send_command(int cmd, int opt) {
/* Send a command to the telnet client */
if (cmd == DO || cmd == DONT) {
/* DO commands say what the client should do. */
if (((cmd == DO) && (telnet_do_set[opt] != DO)) ||
((cmd == DONT) && (telnet_do_set[opt] != DONT))) {
/* And we only send them if there is a disagreement */
telnet_do_set[opt] = cmd;
printf("%c%c%c", IAC, cmd, opt);
}
} else if (cmd == WILL || cmd == WONT) {
/* Similarly, WILL commands say what the server will do. */
if (((cmd == WILL) && (telnet_will_set[opt] != WILL)) ||
((cmd == WONT) && (telnet_will_set[opt] != WONT))) {
/* And we only send them during disagreements */
telnet_will_set[opt] = cmd;
printf("%c%c%c", IAC, cmd, opt);
}
} else {
/* Other commands are sent raw */
printf("%c%c", IAC, cmd);
}
}
/*
* Print the usage / help text describing options
*/
void usage(char * argv[]) {
printf(
"Terminal Nyancat\n"
"\n"
"usage: %s [-hitn] [-f \033[3mframes\033[0m]\n"
"\n"
" -i --intro \033[3mShow the introduction / about information at startup.\033[0m\n"
" -t --telnet \033[3mTelnet mode.\033[0m\n"
" -n --no-counter \033[3mDo not display the timer\033[0m\n"
" -s --no-title \033[3mDo not set the titlebar text\033[0m\n"
" -e --no-clear \033[3mDo not clear the display between frames\033[0m\n"
" -f --frames \033[3mDisplay the requested number of frames, then quit\033[0m\n"
" -r --min-rows \033[3mCrop the animation from the top\033[0m\n"
" -R --max-rows \033[3mCrop the animation from the bottom\033[0m\n"
" -c --min-cols \033[3mCrop the animation from the left\033[0m\n"
" -C --max-cols \033[3mCrop the animation from the right\033[0m\n"
" -W --width \033[3mCrop the animation to the given width\033[0m\n"
" -H --height \033[3mCrop the animation to the given height\033[0m\n"
" -h --help \033[3mShow this help message.\033[0m\n",
argv[0]);
}
int main(int argc, char ** argv) {
/* The default terminal is ANSI */
char term[1024] = {'a','n','s','i', 0};
unsigned int k;
int ttype;
uint32_t option = 0, done = 0, sb_mode = 0;
/* Various pieces for the telnet communication */
char sb[1024] = {0};
unsigned short sb_len = 0;
/* Whether or not to show the MOTD intro */
char show_intro = 0;
char skip_intro = 0;
/* Long option names */
static struct option long_opts[] = {
{"help", no_argument, 0, 'h'},
{"telnet", no_argument, 0, 't'},
{"intro", no_argument, 0, 'i'},
{"skip-intro", no_argument, 0, 'I'},
{"no-counter", no_argument, 0, 'n'},
{"no-title", no_argument, 0, 's'},
{"no-clear", no_argument, 0, 'e'},
{"frames", required_argument, 0, 'f'},
{"min-rows", required_argument, 0, 'r'},
{"max-rows", required_argument, 0, 'R'},
{"min-cols", required_argument, 0, 'c'},
{"max-cols", required_argument, 0, 'C'},
{"width", required_argument, 0, 'W'},
{"height", required_argument, 0, 'H'},
{0,0,0,0}
};
/* Process arguments */
int index, c;
while ((c = getopt_long(argc, argv, "eshiItnf:r:R:c:C:W:H:", long_opts, &index)) != -1) {
if (!c) {
if (long_opts[index].flag == 0) {
c = long_opts[index].val;
}
}
switch (c) {
case 'e':
clear_screen = 0;
break;
case 's':
set_title = 0;
break;
case 'i': /* Show introduction */
show_intro = 1;
break;
case 'I':
skip_intro = 1;
break;
case 't': /* Expect telnet bits */
telnet = 1;
break;
case 'h': /* Show help and exit */
usage(argv);
exit(0);
break;
case 'n':
show_counter = 0;
break;
case 'f':
frame_count = atoi(optarg);
break;
case 'r':
min_row = atoi(optarg);
break;
case 'R':
max_row = atoi(optarg);
break;
case 'c':
min_col = atoi(optarg);
break;
case 'C':
max_col = atoi(optarg);
break;
case 'W':
min_col = (FRAME_WIDTH - atoi(optarg)) / 2;
max_col = (FRAME_WIDTH + atoi(optarg)) / 2;
break;
case 'H':
min_row = (FRAME_HEIGHT - atoi(optarg)) / 2;
max_row = (FRAME_HEIGHT + atoi(optarg)) / 2;
break;
default:
break;
}
}
#if 0
if (telnet) {
/* Telnet mode */
/* show_intro is implied unless skip_intro was set */
show_intro = (skip_intro == 0) ? 1 : 0;
/* Set the default options */
set_options();
/* Let the client know what we're using */
for (option = 0; option < 256; option++) {
if (telnet_options[option]) {
send_command(telnet_options[option], option);
fflush(stdout);
}
}
for (option = 0; option < 256; option++) {
if (telnet_willack[option]) {
send_command(telnet_willack[option], option);
fflush(stdout);
}
}
/* Set the alarm handler to execute the longjmp */
signal(SIGALRM, SIGALRM_handler);
/* Negotiate options */
if (!setjmp(environment)) {
/* We will stop handling options after one second */
alarm(1);
/* Let's do this */
while (!feof(stdin) && done < 2) {
/* Get either IAC (start command) or a regular character (break, unless in SB mode) */
unsigned char i = getchar();
unsigned char opt = 0;
if (i == IAC) {
/* If IAC, get the command */
i = getchar();
switch (i) {
case SE:
/* End of extended option mode */
sb_mode = 0;
if (sb[0] == TTYPE) {
/* This was a response to the TTYPE command, meaning
* that this should be a terminal type */
alarm(2);
strcpy(term, &sb[2]);
done++;
}
else if (sb[0] == NAWS) {
/* This was a response to the NAWS command, meaning
* that this should be a window size */
alarm(2);
terminal_width = (sb[1] << 8) | sb[2];
terminal_height = (sb[3] << 8) | sb[4];
done++;
}
break;
case NOP:
/* No Op */
send_command(NOP, 0);
fflush(stdout);
break;
case WILL:
case WONT:
/* Will / Won't Negotiation */
opt = getchar();
if (!telnet_willack[opt]) {
/* We default to WONT */
telnet_willack[opt] = WONT;
}
send_command(telnet_willack[opt], opt);
fflush(stdout);
if ((i == WILL) && (opt == TTYPE)) {
/* WILL TTYPE? Great, let's do that now! */
printf("%c%c%c%c%c%c", IAC, SB, TTYPE, SEND, IAC, SE);
fflush(stdout);
}
break;
case DO:
case DONT:
/* Do / Don't Negotiation */
opt = getchar();
if (!telnet_options[opt]) {
/* We default to DONT */
telnet_options[opt] = DONT;
}
send_command(telnet_options[opt], opt);
fflush(stdout);
break;
case SB:
/* Begin Extended Option Mode */
sb_mode = 1;
sb_len = 0;
memset(sb, 0, sizeof(sb));
break;
case IAC:
/* IAC IAC? That's probably not right. */
done = 2;
break;
default:
break;
}
} else if (sb_mode) {
/* Extended Option Mode -> Accept character */
if (sb_len < sizeof(sb) - 1) {
/* Append this character to the SB string,
* but only if it doesn't put us over
* our limit; honestly, we shouldn't hit
* the limit, as we're only collecting characters
* for a terminal type or window size, but better safe than
* sorry (and vulnerable).
*/
sb[sb_len] = i;
sb_len++;
}
}
}
}
alarm(0);
} else {
#else
{
#endif
/* We are running standalone, retrieve the
* terminal type from the environment. */
char * nterm = getenv("TERM");
if (nterm) {
strcpy(term, nterm);
}
/* Also get the number of columns */
struct winsize w;
ioctl(0, TIOCGWINSZ, &w);
terminal_width = w.ws_col;
terminal_height = w.ws_row;
}
/* Convert the entire terminal string to lower case */
for (k = 0; k < strlen(term); ++k) {
term[k] = tolower(term[k]);
}
/* Do our terminal detection */
if (strstr(term, "xterm")) {
ttype = 1; /* 256-color, spaces */
} else if (strstr(term, "toaru")) {
ttype = 1; /* emulates xterm */
} else if (strstr(term, "linux")) {
ttype = 3; /* Spaces and blink attribute */
} else if (strstr(term, "vtnt")) {
ttype = 5; /* Extended ASCII fallback == Windows */
} else if (strstr(term, "cygwin")) {
ttype = 5; /* Extended ASCII fallback == Windows */
} else if (strstr(term, "vt220")) {
ttype = 6; /* No color support */
} else if (strstr(term, "fallback")) {
ttype = 4; /* Unicode fallback */
} else if (strstr(term, "rxvt")) {
ttype = 3; /* Accepts LINUX mode */
} else if (strstr(term, "vt100") && terminal_width == 40) {
ttype = 7; /* No color support, only 40 columns */
} else if (!strncmp(term, "st", 2)) {
ttype = 1; /* suckless simple terminal is xterm-256color-compatible */
} else {
ttype = 2; /* Everything else */
}
int always_escape = 0; /* Used for text mode */
/* Accept ^C -> restore cursor */
signal(SIGINT, SIGINT_handler);
/* Handle loss of stdout */
signal(SIGPIPE, SIGPIPE_handler);
/* Handle window changes */
if (!telnet) {
signal(SIGWINCH, SIGWINCH_handler);
}
switch (ttype) {
case 1:
colors[','] = "\033[48;5;17m"; /* Blue background */
colors['.'] = "\033[48;5;231m"; /* White stars */
colors['\''] = "\033[48;5;16m"; /* Black border */
colors['@'] = "\033[48;5;230m"; /* Tan poptart */
colors['$'] = "\033[48;5;175m"; /* Pink poptart */
colors['-'] = "\033[48;5;162m"; /* Red poptart */
colors['>'] = "\033[48;5;196m"; /* Red rainbow */
colors['&'] = "\033[48;5;214m"; /* Orange rainbow */
colors['+'] = "\033[48;5;226m"; /* Yellow Rainbow */
colors['#'] = "\033[48;5;118m"; /* Green rainbow */
colors['='] = "\033[48;5;33m"; /* Light blue rainbow */
colors[';'] = "\033[48;5;19m"; /* Dark blue rainbow */
colors['*'] = "\033[48;5;240m"; /* Gray cat face */
colors['%'] = "\033[48;5;175m"; /* Pink cheeks */
break;
case 2:
colors[','] = "\033[104m"; /* Blue background */
colors['.'] = "\033[107m"; /* White stars */
colors['\''] = "\033[40m"; /* Black border */
colors['@'] = "\033[47m"; /* Tan poptart */
colors['$'] = "\033[105m"; /* Pink poptart */
colors['-'] = "\033[101m"; /* Red poptart */
colors['>'] = "\033[101m"; /* Red rainbow */
colors['&'] = "\033[43m"; /* Orange rainbow */
colors['+'] = "\033[103m"; /* Yellow Rainbow */
colors['#'] = "\033[102m"; /* Green rainbow */
colors['='] = "\033[104m"; /* Light blue rainbow */
colors[';'] = "\033[44m"; /* Dark blue rainbow */
colors['*'] = "\033[100m"; /* Gray cat face */
colors['%'] = "\033[105m"; /* Pink cheeks */
break;
case 3:
colors[','] = "\033[25;44m"; /* Blue background */
colors['.'] = "\033[5;47m"; /* White stars */
colors['\''] = "\033[25;40m"; /* Black border */
colors['@'] = "\033[5;47m"; /* Tan poptart */
colors['$'] = "\033[5;45m"; /* Pink poptart */
colors['-'] = "\033[5;41m"; /* Red poptart */
colors['>'] = "\033[5;41m"; /* Red rainbow */
colors['&'] = "\033[25;43m"; /* Orange rainbow */
colors['+'] = "\033[5;43m"; /* Yellow Rainbow */
colors['#'] = "\033[5;42m"; /* Green rainbow */
colors['='] = "\033[25;44m"; /* Light blue rainbow */
colors[';'] = "\033[5;44m"; /* Dark blue rainbow */
colors['*'] = "\033[5;40m"; /* Gray cat face */
colors['%'] = "\033[5;45m"; /* Pink cheeks */
break;
case 4:
colors[','] = "\033[0;34;44m"; /* Blue background */
colors['.'] = "\033[1;37;47m"; /* White stars */
colors['\''] = "\033[0;30;40m"; /* Black border */
colors['@'] = "\033[1;37;47m"; /* Tan poptart */
colors['$'] = "\033[1;35;45m"; /* Pink poptart */
colors['-'] = "\033[1;31;41m"; /* Red poptart */
colors['>'] = "\033[1;31;41m"; /* Red rainbow */
colors['&'] = "\033[0;33;43m"; /* Orange rainbow */
colors['+'] = "\033[1;33;43m"; /* Yellow Rainbow */
colors['#'] = "\033[1;32;42m"; /* Green rainbow */
colors['='] = "\033[1;34;44m"; /* Light blue rainbow */
colors[';'] = "\033[0;34;44m"; /* Dark blue rainbow */
colors['*'] = "\033[1;30;40m"; /* Gray cat face */
colors['%'] = "\033[1;35;45m"; /* Pink cheeks */
output = "██";
break;
case 5:
colors[','] = "\033[0;34;44m"; /* Blue background */
colors['.'] = "\033[1;37;47m"; /* White stars */
colors['\''] = "\033[0;30;40m"; /* Black border */
colors['@'] = "\033[1;37;47m"; /* Tan poptart */
colors['$'] = "\033[1;35;45m"; /* Pink poptart */
colors['-'] = "\033[1;31;41m"; /* Red poptart */
colors['>'] = "\033[1;31;41m"; /* Red rainbow */
colors['&'] = "\033[0;33;43m"; /* Orange rainbow */
colors['+'] = "\033[1;33;43m"; /* Yellow Rainbow */
colors['#'] = "\033[1;32;42m"; /* Green rainbow */
colors['='] = "\033[1;34;44m"; /* Light blue rainbow */
colors[';'] = "\033[0;34;44m"; /* Dark blue rainbow */
colors['*'] = "\033[1;30;40m"; /* Gray cat face */
colors['%'] = "\033[1;35;45m"; /* Pink cheeks */
output = "\333\333";
break;
case 6:
colors[','] = "::"; /* Blue background */
colors['.'] = "@@"; /* White stars */
colors['\''] = " "; /* Black border */
colors['@'] = "##"; /* Tan poptart */
colors['$'] = "??"; /* Pink poptart */
colors['-'] = "<>"; /* Red poptart */
colors['>'] = "##"; /* Red rainbow */
colors['&'] = "=="; /* Orange rainbow */
colors['+'] = "--"; /* Yellow Rainbow */
colors['#'] = "++"; /* Green rainbow */
colors['='] = "~~"; /* Light blue rainbow */
colors[';'] = "$$"; /* Dark blue rainbow */
colors['*'] = ";;"; /* Gray cat face */
colors['%'] = "()"; /* Pink cheeks */
always_escape = 1;
break;
case 7:
colors[','] = "."; /* Blue background */
colors['.'] = "@"; /* White stars */
colors['\''] = " "; /* Black border */
colors['@'] = "#"; /* Tan poptart */
colors['$'] = "?"; /* Pink poptart */
colors['-'] = "O"; /* Red poptart */
colors['>'] = "#"; /* Red rainbow */
colors['&'] = "="; /* Orange rainbow */
colors['+'] = "-"; /* Yellow Rainbow */
colors['#'] = "+"; /* Green rainbow */
colors['='] = "~"; /* Light blue rainbow */
colors[';'] = "$"; /* Dark blue rainbow */
colors['*'] = ";"; /* Gray cat face */
colors['%'] = "o"; /* Pink cheeks */
always_escape = 1;
terminal_width = 40;
break;
default:
break;
}
if (min_col == max_col) {
min_col = (FRAME_WIDTH - terminal_width/2) / 2;
max_col = (FRAME_WIDTH + terminal_width/2) / 2;
using_automatic_width = 1;
}
if (min_row == max_row) {
min_row = (FRAME_HEIGHT - (terminal_height-1)) / 2;
max_row = (FRAME_HEIGHT + (terminal_height-1)) / 2;
using_automatic_height = 1;
}
/* Attempt to set terminal title */
if (set_title) {
printf("\033kNyanyanyanyanyanyanya...\033\134");
printf("\033]1;Nyanyanyanyanyanyanya...\007");
printf("\033]2;Nyanyanyanyanyanyanya...\007");
}
if (clear_screen) {
/* Clear the screen */
printf("\033[H\033[2J\033[?25l");
} else {
printf("\033[s");
}
if (show_intro) {
/* Display the MOTD */
unsigned int countdown_clock = 5;
for (k = 0; k < countdown_clock; ++k) {
newline(3);
printf(" \033[1mNyancat Telnet Server\033[0m");
newline(2);
printf(" written and run by \033[1;32mKevin Lange\033[1;34m @kevinlange\033[0m");
newline(2);
printf(" If things don't look right, try:");
newline(1);
printf(" TERM=fallback telnet ...");
newline(2);
printf(" Or on Windows:");
newline(1);
printf(" telnet -t vtnt ...");
newline(2);
printf(" Problems? Check the website:");
newline(1);
printf(" \033[1;34mhttp://nyancat.dakko.us\033[0m");
newline(2);
printf(" This is a telnet server, remember your escape keys!");
newline(1);
printf(" \033[1;31m^]quit\033[0m to exit");
newline(2);
printf(" Starting in %d... \n", countdown_clock-k);
fflush(stdout);
usleep(400000);
if (clear_screen) {
printf("\033[H"); /* Reset cursor */
} else {
printf("\033[u");
}
}
if (clear_screen) {
/* Clear the screen again */
printf("\033[H\033[2J\033[?25l");
}
}
/* Store the start time */
time_t start, current;
time(&start);
int playing = 1; /* Animation should continue [left here for modifications] */
size_t i = 0; /* Current frame # */
unsigned int f = 0; /* Total frames passed */
char last = 0; /* Last color index rendered */
int y, x; /* x/y coordinates of what we're drawing */
while (playing) {
/* Reset cursor */
if (clear_screen) {
printf("\033[H");
} else {
printf("\033[u");
}
/* Render the frame */
for (y = min_row; y < max_row; ++y) {
for (x = min_col; x < max_col; ++x) {
char color;
if (y > 23 && y < 43 && x < 0) {
/*
* Generate the rainbow tail.
*
* This is done with a pretty simplistic square wave.
*/
int mod_x = ((-x+2) % 16) / 8;
if ((i / 2) % 2) {
mod_x = 1 - mod_x;
}
/*
* Our rainbow, with some padding.
*/
const char *rainbow = ",,>>&&&+++###==;;;,,";
color = rainbow[mod_x + y-23];
if (color == 0) color = ',';
} else if (x < 0 || y < 0 || y >= FRAME_HEIGHT || x >= FRAME_WIDTH) {
/* Fill all other areas with background */
color = ',';
} else {
/* Otherwise, get the color from the animation frame. */
color = frames[i][y][x];
}
if (always_escape) {
/* Text mode (or "Always Send Color Escapes") */
printf("%s", colors[(int)color]);
} else {
if (color != last && colors[(int)color]) {
/* Normal Mode, send escape (because the color changed) */
last = color;
printf("%s%s", colors[(int)color], output);
} else {
/* Same color, just send the output characters */
printf("%s", output);
}
}
}
/* End of row, send newline */
newline(1);
}
if (show_counter) {
/* Get the current time for the "You have nyaned..." string */
time(&current);
double diff = difftime(current, start);
/* Now count the length of the time difference so we can center */
int nLen = digits((int)diff);
/*
* 29 = the length of the rest of the string;
* XXX: Replace this was actually checking the written bytes from a
* call to sprintf or something
*/
int width = (terminal_width - 29 - nLen) / 2;
/* Spit out some spaces so that we're actually centered */
while (width > 0) {
printf(" ");
width--;
}
/* You have nyaned for [n] seconds!
* The \033[J ensures that the rest of the line has the dark blue
* background, and the \033[1;37m ensures that our text is bright white.
* The \033[0m prevents the Apple ][ from flipping everything, but
* makes the whole nyancat less bright on the vt220
*/
printf("\033[1;37mYou have nyaned for %0.0f seconds!\033[J\033[0m", diff);
}
/* Reset the last color so that the escape sequences rewrite */
last = 0;
/* Update frame count */
++f;
if (frame_count != 0 && f == frame_count) {
finish();
}
++i;
if (!frames[i]) {
/* Loop animation */
i = 0;
}
/* Wait */
usleep(90000);
}
return 0;
}