diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/nyancat.c | 201 |
1 files changed, 143 insertions, 58 deletions
diff --git a/src/nyancat.c b/src/nyancat.c index 7554630..5fa8825 100644 --- a/src/nyancat.c +++ b/src/nyancat.c @@ -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) { - sb[sb_len] = i; - sb_len++; + /* 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: @@ -257,63 +330,65 @@ ready: 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['$'] = "\033[1;35;45m"; /* Pink poptart */ - colors['-'] = "\033[1;31;41m"; /* Red poptart */ - colors['>'] = "\033[1;31;41m"; /* Red rainbow */ - colors['&'] = "\033[0;33;43m"; /* Orange rainbow */ - colors['+'] = "\033[1;33;43m"; /* Yellow Rainbow */ - colors['#'] = "\033[1;32;42m"; /* Green rainbow */ - colors['='] = "\033[1;34;44m"; /* Light blue rainbow */ - colors[';'] = "\033[0;34;44m"; /* Dark blue rainbow */ - colors['*'] = "\033[1;30;40m"; /* Gray cat face */ - colors['%'] = "\033[1;35;45m"; /* Pink cheeks */ + colors[','] = "\033[0;34;44m"; /* Blue background */ + colors['.'] = "\033[1;37;47m"; /* White stars */ + colors['\''] = "\033[0;30;40m"; /* Black border */ + colors['@'] = "\033[1;37;47m"; /* Tan poptart */ + colors['$'] = "\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['$'] = "\033[1;35;45m"; /* Pink poptart */ - colors['-'] = "\033[1;31;41m"; /* Red poptart */ - colors['>'] = "\033[1;31;41m"; /* Red rainbow */ - colors['&'] = "\033[0;33;43m"; /* Orange rainbow */ - colors['+'] = "\033[1;33;43m"; /* Yellow Rainbow */ - colors['#'] = "\033[1;32;42m"; /* Green rainbow */ - colors['='] = "\033[1;34;44m"; /* Light blue rainbow */ - colors[';'] = "\033[0;34;44m"; /* Dark blue rainbow */ - colors['*'] = "\033[1;30;40m"; /* Gray cat face */ - colors['%'] = "\033[1;35;45m"; /* Pink cheeks */ + colors[','] = "\033[0;34;44m"; /* Blue background */ + colors['.'] = "\033[1;37;47m"; /* White stars */ + colors['\''] = "\033[0;30;40m"; /* Black border */ + colors['@'] = "\033[1;37;47m"; /* Tan poptart */ + colors['$'] = "\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[';'] = "$$"; /* Dark blue rainbow */ - colors['*'] = ";;"; /* Gray cat face */ - colors['%'] = "()"; /* Pink cheeks */ + colors[','] = "::"; /* Blue background */ + colors['.'] = "@@"; /* White stars */ + colors['\''] = " "; /* Black border */ + colors['@'] = "##"; /* Tan poptart */ + colors['$'] = "??"; /* Pink poptart */ + colors['-'] = "<>"; /* Red poptart */ + colors['>'] = "##"; /* Red rainbow */ + colors['&'] = "=="; /* Orange rainbow */ + colors['+'] = "--"; /* Yellow Rainbow */ + colors['#'] = "++"; /* Green rainbow */ + colors['='] = "~~"; /* Light blue rainbow */ + colors[';'] = "$$"; /* Dark blue rainbow */ + colors['*'] = ";;"; /* Gray cat face */ + colors['%'] = "()"; /* Pink cheeks */ always_escape = 1; break; default: 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; |