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Comments? In /my/ code? It's more likely than you think.

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This commit is contained in:
Kevin Lange 2011-12-03 19:49:30 -06:00
parent 93fcebb156
commit cedbee69a2
1 changed files with 143 additions and 58 deletions
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113
src/nyancat.c
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@ -4,6 +4,16 @@
* Developed by: Kevin Lange
* http://github.com/klange/nyancat
*
* 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://miku.acm.uiuc.edu
*
* 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
@ -37,54 +47,95 @@
#include <signal.h>
#include "telnet.h"
/* The animation frames are stored separately. */
#include "animation.h"
/* The color palette is not yet set */
char * colors[256] = {NULL};
/*
* For most modes, we ouput spaces, but for some
* we will use block characters.
*/
char * output = " ";
/*
* These values crop the animation, as we have a full 64x64 stored,
* but we only want to display 80x24.
*/
#define MIN_ROW 20
#define MAX_ROW 44
#define MIN_COL 10
#define MAX_COL 50
/*
* In the standalone mode, we want to handle an interrupt signal
* (^C) so that we can restore the cursor.
*/
void SIGINT_handler(int sig){
printf("\033[?25h");
exit(0);
}
/*
* 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 the window size */
telnet_willack[NAWS] = DONT;
/* 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;
}
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);
}
}
@ -92,17 +143,23 @@ void send_command(int cmd, int opt) {
int main(int argc, char ** argv) {
/* I have a bad habit of being very C99, so this may not be everything */
/* The default terminal is ANSI */
char term[1024] = {'a','n','s','i'};
int k, ttype;
uint32_t option = 0, done = 0, sb_mode = 0, do_echo = 0;
char term[1024] = {'a','n','s','i'};
/* Various pieces for the telnet communication */
char sb[1024] = {0};
char sb_len = 0;
if (argc > 1) {
if (!strcmp(argv[1], "-t")) {
/* Yes, I know, lame way to get arguments, whatever, we only want one of them. */
/* 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);
@ -116,13 +173,15 @@ int main(int argc, char ** argv) {
}
}
/* Negotiate options */
while (!feof(stdin) && !done) {
unsigned char i = getchar();
unsigned char opt = 0;
if (i == 255) {
if (i == IAC) {
i = getchar();
switch (i) {
case SE:
/* End of extended option mode */
sb_mode = 0;
if (sb[0] == TTYPE) {
strcpy(term, &sb[2]);
@ -130,11 +189,13 @@ int main(int argc, char ** argv) {
}
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]) {
telnet_willack[opt] = WONT;
@ -142,70 +203,82 @@ int main(int argc, char ** argv) {
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 Negotation */
opt = getchar();
if (!telnet_options[opt]) {
telnet_options[opt] = DONT;
}
send_command(telnet_options[opt], opt);
if (opt == ECHO) {
/* We don't really need this, as we don't accept input, but,
* in case we do in the future, set our echo mode */
do_echo = (i == DO);
}
fflush(stdout);
break;
case SB:
/* Begin Extended Option Mode */
sb_mode = 1;
sb_len = 0;
memset(sb, 0, 1024);
break;
case IAC:
/* Connection Closed */
/* Connection Closed During Negotiation */
done = 1;
break;
default:
break;
}
} else if (sb_mode) {
/* Extended Option Mode -> Accept character */
if (sb_len < 1023) {
sb[sb_len] = i;
sb_len++;
}
}
}
}
} else {
/* Otherwise, we were run standalone, find the terminal type from the environement */
char * nterm = getenv("TERM");
strcpy(term, nterm);
}
ready:
/* 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;
ttype = 1; /* 256-color, spaces */
} else if (strstr(term, "linux")) {
ttype = 3;
ttype = 3; /* Spaces and blink attribute */
} else if (strstr(term, "vtnt")) {
ttype = 5;
ttype = 5; /* Extended ASCII fallback == Windows */
} else if (strstr(term, "cygwin")) {
ttype = 5;
ttype = 5; /* Extended ASCII fallback == Windows */
} else if (strstr(term, "vt220")) {
ttype = 6;
ttype = 6; /* No color support */
} else if (strstr(term, "fallback")) {
ttype = 4;
ttype = 4; /* Unicode fallback */
} else if (strstr(term, "rxvt")) {
ttype = 3;
ttype = 3; /* Accepts LINUX mode */
} else {
ttype = 2;
ttype = 2; /* Verything else */
}
int always_escape = 0;
int always_escape = 0; /* Used for text mode */
/* Accept ^C -> restore cursor */
signal(SIGINT, SIGINT_handler);
switch (ttype) {
case 1:
@ -311,9 +384,11 @@ ready:
break;
}
/* Clear the screen */
printf("\033[H\033[2J\033[?25l");
/* Display the MOTD */
int countdown_clock = 5;
for (k = 0; k < countdown_clock; ++k) {
printf("\n\n\n");
@ -333,9 +408,10 @@ ready:
fflush(stdout);
usleep(400000);
printf("\033[H");
printf("\033[H"); /* Reset cursor */
}
/* Clear the screen again */
printf("\033[H\033[2J\033[?25l");
int playing = 1;
@ -343,27 +419,36 @@ ready:
char last = 0;
size_t y, x;
while (playing) {
/* Render the frame */
for (y = MIN_ROW; y < MAX_ROW; ++y) {
for (x = MIN_COL; x < MAX_COL; ++x) {
if (always_escape) {
/* Text mode (or "Always Send Color Escapse") */
printf("%s", colors[frames[i][y][x]]);
} else {
if (frames[i][y][x] != last && colors[frames[i][y][x]]) {
/* Normal Mode, send escape (because the color changed) */
last = frames[i][y][x];
printf("%s%s", colors[frames[i][y][x]], output);
} else {
/* Same color, just send the output characters */
printf("%s", output);
}
}
}
/* End of row, send newline */
if (y != MAX_ROW - 1)
printf("\n");
}
/* Update frame crount */
++i;
if (!frames[i]) {
/* Loop animation */
i = 0;
}
/* Reset cursor */
printf("\033[H");
/* Wait */
usleep(90000);
}
return 0;