Usermode/Applications/irc_src/main.c

   1 /*
   2  * Acess2 IRC Client
   3  */
   4 #include <acess/sys.h>
   5 #include <stdlib.h>
   6 #include <stdio.h>
   7 #include <string.h>
   8 #include <net.h>
   9 #include <readline.h>
  10 #include <acess/devices/pty.h>
  11
  12 // === TYPES ===
  13 typedef struct sServer {
  14         struct sServer  *Next;
  15          int    FD;
  16         char    InBuf[BUFSIZ+1];
  17          int    ReadPos;
  18         char    Name[];
  19 } tServer;
  20
  21 typedef struct sMessage
  22 {
  23         struct sMessage *Next;
  24         time_t  Timestamp;
  25         tServer *Server;
  26          int    Type;
  27         char    *Source;        // Pointer into `Data`
  28         char    Data[];
  29 }       tMessage;
  30
  31 typedef struct sWindow
  32 {
  33         struct sWindow  *Next;
  34         tMessage        *Messages;
  35         tServer *Server;        //!< Canoical server (can be NULL)
  36          int    ActivityLevel;
  37         char    Name[]; // Channel name / remote user
  38 }       tWindow;
  39
  40 enum eMessageTypes
  41 {
  42         MSG_TYPE_NULL,
  43         MSG_TYPE_SERVER,        // Server message
  44
  45         MSG_TYPE_NOTICE,        // NOTICE command
  46         MSG_TYPE_JOIN,  // JOIN command
  47         MSG_TYPE_PART,  // PART command
  48         MSG_TYPE_QUIT,  // QUIT command
  49
  50         MSG_TYPE_STANDARD,      // Standard line
  51         MSG_TYPE_ACTION,        // /me
  52
  53         MSG_TYPE_UNK
  54 };
  55
  56 // === PROTOTYPES ===
  57  int    ParseArguments(int argc, const char *argv[]);
  58  int    ParseUserCommand(char *String);
  59 // ---
  60 tServer *Server_Connect(const char *Name, const char *AddressString, short PortNumber);
  61 tMessage        *Message_AppendF(tServer *Server, int Type, const char *Source, const char *Dest, const char *Message, ...);
  62 tMessage        *Message_Append(tServer *Server, int Type, const char *Source, const char *Dest, const char *Message);
  63 tWindow *Window_Create(tServer *Server, const char *Name);
  64 void    Redraw_Screen(void);
  65
  66  int    ProcessIncoming(tServer *Server);
  67 // --- Helpers
  68 void    SetCursorPos(int Row, int Col);
  69  int    writef(int FD, const char *Format, ...);
  70  int    OpenTCP(const char *AddressString, short PortNumber);
  71 char    *GetValue(char *Str, int *Ofs);
  72 static inline int       isdigit(int ch);
  73
  74 // === GLOBALS ===
  75 char    *gsUsername = "user";
  76 char    *gsHostname = "acess";
  77 char    *gsRealName = "Acess2 IRC Client";
  78 char    *gsNickname = "acess";
  79 tServer *gpServers;
  80 tWindow gWindow_Status = {
  81         NULL, NULL, NULL,       // No next, empty list, no server
  82         0, {""} // No activity, empty name (rendered as status)
  83 };
  84 tWindow *gpWindows = &gWindow_Status;
  85 tWindow *gpCurrentWindow = &gWindow_Status;
  86  int    giTerminal_Width = 80;
  87  int    giTerminal_Height = 25;
  88
  89 // ==== CODE ====
  90 void ExitHandler(void)
  91 {
  92         printf("\x1B[?1047l");
  93         printf("Quit\n");
  94 }
  95
  96 int main(int argc, const char *argv[], const char *envp[])
  97 {
  98          int    tmp;
  99         tReadline       *readline_info;
 100
 101         // Parse Command line
 102         if( (tmp = ParseArguments(argc, argv)) )        return tmp;
 103
 104         atexit(ExitHandler);
 105
 106         if( _SysIOCtl(1, DRV_IOCTL_TYPE, NULL) != DRV_TYPE_TERMINAL ) {
 107                 printf(stderr, "note: assuming 80x25, can't get terminal dimensions\n");
 108                 giTerminal_Width = 80;
 109                 giTerminal_Height = 25;
 110         }
 111         else {
 112                 struct ptydims  dims;
 113                 _SysIOCtl(1, PTY_IOCTL_GETDIMS, &dims);
 114                 giTerminal_Width = dims.W;
 115                 giTerminal_Height = dims.H;
 116         }
 117
 118         printf("\x1B[?1047h");
 119         printf("\x1B[%i;%ir", 0, giTerminal_Height-1);
 120
 121         SetCursorPos(giTerminal_Height-1, 0);
 122         printf("[(status)] ");
 123
 124         // HACK: Static server entry
 125         // UCC (University [of Western Australia] Computer Club) IRC Server
 126         gWindow_Status.Server = Server_Connect( "UCC", "130.95.13.18", 6667 );
 127         // Freenode (#osdev)
 128 //      gWindow_Status.Server = Server_Connect( "Freenode", "89.16.176.16", 6667 );
 129 //      gWindow_Status.Server = Server_Connect( "Host", "10.0.2.2", 6667 );
 130         // Local server
 131 //      gWindow_Status.Server = Server_Connect( "BitlBee", "192.168.1.39", 6667 );
 132
 133         if( !gWindow_Status.Server )
 134                 return -1;
 135
 136         SetCursorPos(giTerminal_Height-1, 0);
 137         printf("[(status)] ");
 138         fflush(stdout);
 139         readline_info = Readline_Init(1);
 140
 141         for( ;; )
 142         {
 143                 fd_set  readfds, errorfds;
 144                  int    rv, maxFD = 0;
 145                 tServer *srv;
 146
 147                 FD_ZERO(&readfds);
 148                 FD_ZERO(&errorfds);
 149                 FD_SET(0, &readfds);    // stdin
 150
 151                 // Fill server FDs in fd_set
 152                 for( srv = gpServers; srv; srv = srv->Next )
 153                 {
 154                         FD_SET(srv->FD, &readfds);
 155                         FD_SET(srv->FD, &errorfds);
 156                         if( srv->FD > maxFD )
 157                                 maxFD = srv->FD;
 158                 }
 159
 160                 rv = _SysSelect(maxFD+1, &readfds, 0, &errorfds, NULL, 0);
 161                 if( rv == -1 )  break;
 162
 163                 if(FD_ISSET(0, &readfds))
 164                 {
 165                         // User input
 166                         char    *cmd = Readline_NonBlock(readline_info);
 167                         if( cmd )
 168                         {
 169                                 if( cmd[0] )
 170                                 {
 171                                         ParseUserCommand(cmd);
 172                                 }
 173                                 free(cmd);
 174                                 // Prompt
 175                                 SetCursorPos(giTerminal_Height-1, 0);
 176                                 printf("\x1B[K");       // Clear line
 177                                 if( gpCurrentWindow->Name[0] )
 178                                         printf("[%s:%s] ", gpCurrentWindow->Server->Name, gpCurrentWindow->Name);
 179                                 else
 180                                         printf("[(status)] ");
 181                                 fflush(stdout);
 182                         }
 183                 }
 184
 185                 // Server response
 186                 for( srv = gpServers; srv; srv = srv->Next )
 187                 {
 188                         if(FD_ISSET(srv->FD, &readfds))
 189                         {
 190                                 if( ProcessIncoming(srv) != 0 ) {
 191                                         // Oops, error
 192                                         break;
 193                                 }
 194                         }
 195
 196                         if(FD_ISSET(srv->FD, &errorfds))
 197                         {
 198                                 break;
 199                         }
 200                 }
 201
 202                 // Oops, an error
 203                 if( srv )       break;
 204         }
 205
 206         {
 207                 tServer *srv;
 208                 for( srv = gpServers; srv; srv = srv->Next )
 209                         _SysClose(srv->FD);
 210         }
 211         return 0;
 212 }
 213
 214 /**
 215  * \todo Actually implement correctly :)
 216  */
 217 int ParseArguments(int argc, const char *argv[])
 218 {
 219         return 0;
 220 }
 221
 222
 223 void Cmd_join(char *ArgString)
 224 {
 225          int    pos=0;
 226         char    *channel_name = GetValue(ArgString, &pos);
 227
 228         if( gpCurrentWindow->Server )
 229         {
 230                 writef(gpCurrentWindow->Server->FD, "JOIN :%s\n", channel_name);
 231         }
 232 }
 233
 234 void Cmd_quit(char *ArgString)
 235 {
 236         const char *quit_message = ArgString;
 237         if( quit_message == NULL || quit_message[0] == '\0' )
 238                 quit_message = "/quit - Acess2 IRC Client";
 239
 240         for( tServer *srv = gpServers; srv; srv = srv->Next )
 241         {
 242                 writef(srv->FD, "QUIT :%s\n", quit_message);
 243         }
 244
 245         exit(0);
 246 }
 247
 248 void Cmd_window(char *ArgString)
 249 {
 250          int    pos = 0;
 251         char    *window_id = GetValue(ArgString, &pos);
 252          int    window_num = atoi(window_id);
 253
 254         if( window_num > 0 )
 255         {
 256                 tWindow *win;
 257                 window_num --;  // Move to base 0
 258                 // Get `window_num`th window
 259                 for( win = gpWindows; win && window_num--; win = win->Next );
 260                 if( win ) {
 261                         gpCurrentWindow = win;
 262                         Redraw_Screen();
 263                 }
 264                 // Otherwise, silently ignore
 265         }
 266         else
 267         {
 268                 window_num = 1;
 269                 for( tWindow *win = gpWindows; win; win = win->Next, window_num ++ )
 270                 {
 271                         if( win->Name[0] ) {
 272                                 Message_AppendF(NULL, MSG_TYPE_SERVER, "client", "",
 273                                         "%i: %s/%s", window_num, win->Server->Name, win->Name);
 274                         }
 275                         else {
 276                                 Message_AppendF(NULL, MSG_TYPE_SERVER, "client", "",
 277                                         "%i: (status)", window_num);
 278                         }
 279                 }
 280         }
 281 }
 282
 283 const struct {
 284         const char *Name;
 285         void    (*Fcn)(char *ArgString);
 286 } caCommands[] = {
 287         {"join", Cmd_join},
 288         {"quit", Cmd_quit},
 289         {"window", Cmd_window},
 290         {"win",    Cmd_window},
 291         {"w",      Cmd_window},
 292 };
 293 const int ciNumCommands = sizeof(caCommands)/sizeof(caCommands[0]);
 294
 295 /**
 296  * \brief Handle a line from the prompt
 297  */
 298 int ParseUserCommand(char *String)
 299 {
 300         if( String[0] == '/' )
 301         {
 302                 char    *command;
 303                  int    pos = 0;
 304
 305                 command = GetValue(String, &pos)+1;
 306
 307                 // TODO: Prefix matches
 308                  int    cmdIdx = -1;
 309                 for( int i = 0; i < ciNumCommands; i ++ )
 310                 {
 311                         if( strcmp(command, caCommands[i].Name) == 0 ) {
 312                                 cmdIdx = i;
 313                                 break;
 314                         }
 315                 }
 316                 if( cmdIdx != -1 ) {
 317                         caCommands[cmdIdx].Fcn(String+pos);
 318                 }
 319                 else
 320                 {
 321                         Message_AppendF(NULL, MSG_TYPE_SERVER, "client", "", "Unknown command %s", command);
 322                 }
 323         }
 324         else
 325         {
 326                 // Message
 327                 // - Only send if server is valid and window name is non-empty
 328                 if( gpCurrentWindow->Server && gpCurrentWindow->Name[0] )
 329                 {
 330                         Message_Append(gpCurrentWindow->Server, MSG_TYPE_STANDARD,
 331                                 gsNickname, gpCurrentWindow->Name, String);
 332                         writef(gpCurrentWindow->Server->FD,
 333                                 "PRIVMSG %s :%s\n", gpCurrentWindow->Name,
 334                                 String
 335                                 );
 336                 }
 337         }
 338
 339         return 0;
 340 }
 341
 342 /**
 343  * \brief Connect to a server
 344  */
 345 tServer *Server_Connect(const char *Name, const char *AddressString, short PortNumber)
 346 {
 347         tServer *ret;
 348
 349         ret = calloc(1, sizeof(tServer) + strlen(Name) + 1);
 350
 351         strcpy(ret->Name, Name);
 352
 353         // Connect to the remove server
 354         ret->FD = OpenTCP( AddressString, PortNumber );
 355         if( ret->FD == -1 ) {
 356                 fprintf(stderr, "%s: Unable to create socket\n", Name);
 357                 return NULL;
 358         }
 359
 360         // Append to open list
 361         ret->Next = gpServers;
 362         gpServers = ret;
 363
 364         // Read some initial data
 365         Message_Append(NULL, MSG_TYPE_SERVER, Name, "", "Connection opened");
 366         ProcessIncoming(ret);
 367
 368         // Identify
 369         writef(ret->FD, "USER %s %s %s : %s\n", gsUsername, gsHostname, AddressString, gsRealName);
 370         writef(ret->FD, "NICK %s\n", gsNickname);
 371         Message_Append(NULL, MSG_TYPE_SERVER, Name, "", "Identified");
 372         //printf("%s: Identified\n", Name);
 373
 374         return ret;
 375 }
 376
 377 tMessage *Message_AppendF(tServer *Server, int Type, const char *Source, const char *Dest, const char *Message, ...)
 378 {
 379         va_list args;
 380          int    len;
 381         va_start(args, Message);
 382         len = vsnprintf(NULL, 0, Message, args);
 383         {
 384                 char    buf[len+1];
 385                 vsnprintf(buf, len+1, Message, args);
 386                 return Message_Append(Server, Type, Source, Dest, buf);
 387         }
 388 }
 389
 390 tMessage *Message_Append(tServer *Server, int Type, const char *Source, const char *Dest, const char *Message)
 391 {
 392         tWindow *win = NULL;
 393          int    msgLen = strlen(Message);
 394
 395         // Server==NULL indicates an internal message
 396         if( Server == NULL || Source[0] == '\0' )
 397         {
 398                 win = &gWindow_Status;
 399         }
 400         // Determine if it's a channel or PM
 401         else if( Dest[0] == '#' || Dest[0] == '&' )     // TODO: Better determining here
 402         {
 403                 for(win = gpWindows; win; win = win->Next)
 404                 {
 405                         if( win->Server == Server && strcmp(win->Name, Dest) == 0 )
 406                         {
 407                                 break;
 408                         }
 409                 }
 410                 if( !win ) {
 411                         win = Window_Create(Server, Dest);
 412                 }
 413         }
 414         #if 0
 415         else if( strcmp(Dest, Server->Nick) != 0 )
 416         {
 417                 // Umm... message for someone who isn't us?
 418                 win = &gWindow_Status;  // Stick it in the status window, just in case
 419         }
 420         #endif
 421         // Server message?
 422         else if( strchr(Source, '.') )  // TODO: And again, less hack please
 423         {
 424                 #if 1
 425                 for(win = gpWindows; win; win = win->Next)
 426                 {
 427                         if( win->Server == Server && strcmp(win->Name, Source) == 0 )
 428                         {
 429                                 break;
 430                         }
 431                 }
 432                 #endif
 433                 if( !win ) {
 434                         win = &gWindow_Status;
 435                 }
 436
 437         }
 438         // Private message
 439         else
 440         {
 441                 for(win = gpWindows; win; win = win->Next)
 442                 {
 443                         if( win->Server == Server && strcmp(win->Name, Source) == 0 )
 444                         {
 445                                 break;
 446                         }
 447                 }
 448                 if( !win ) {
 449                         win = Window_Create(Server, Dest);
 450                 }
 451         }
 452
 453         // Create message cache
 454         _SysDebug("Win (%s) msg: <%s> %s", win->Name, Source, Message);
 455         tMessage        *ret;
 456         ret = malloc( sizeof(tMessage) + msgLen + 1 + strlen(Source) + 1 );
 457         ret->Source = ret->Data + msgLen + 1;
 458         strcpy(ret->Source, Source);
 459         strcpy(ret->Data, Message);
 460         ret->Type = Type;
 461         ret->Server = Server;
 462
 463         // Append to window message list
 464         ret->Next = win->Messages;
 465         win->Messages = ret;
 466
 467         // Print now if current window
 468         if( win == gpCurrentWindow )
 469         {
 470                 printf("\x1b[s");
 471                 SetCursorPos(giTerminal_Height-2, 0);
 472                  int    prefixlen = strlen(Source) + 3;
 473                  int    avail = giTerminal_Width - prefixlen;
 474                  int    msglen = strlen(Message);
 475                 printf("\x1B[T");       // Scroll down 1 (free space below)
 476                 printf("[%s] %.*s\n", Source, avail, Message);
 477                 while( msglen > avail ) {
 478                         msglen -= avail;
 479                         Message += avail;
 480                         printf("\x1B[T");
 481                         SetCursorPos(giTerminal_Height-2, prefixlen);
 482                         printf("%.*s\n", avail, Message);
 483                 }
 484                 printf("\x1b[u");
 485         }
 486
 487         return ret;
 488 }
 489
 490 tWindow *Window_Create(tServer *Server, const char *Name)
 491 {
 492         tWindow *ret, *prev = NULL;
 493          int    num = 1;
 494
 495         // Get the end of the list
 496         // TODO: Cache this instead
 497         for( ret = gpCurrentWindow; ret; prev = ret, ret = ret->Next )
 498                 num ++;
 499
 500         ret = malloc(sizeof(tWindow) + strlen(Name) + 1);
 501         ret->Messages = NULL;
 502         ret->Server = Server;
 503         ret->ActivityLevel = 1;
 504         strcpy(ret->Name, Name);
 505
 506         if( prev ) {
 507                 ret->Next = prev->Next;
 508                 prev->Next = ret;
 509         }
 510         else {  // Shouldn't happen really
 511                 ret->Next = gpWindows;
 512                 gpWindows = ret;
 513         }
 514
 515 //      printf("Win %i %s:%s created\n", num, Server->Name, Name);
 516
 517         return ret;
 518 }
 519
 520 void Redraw_Screen(void)
 521 {
 522          int    y = 0;
 523         tMessage        *msg;
 524
 525         printf("\x1B[2J");      // Clear screen
 526         printf("\x1B[0;0H");    // Reset cursor
 527
 528         msg = gpCurrentWindow->Messages;
 529
 530         // TODO: Title bar?
 531
 532         // Note: This renders from the bottom up
 533         for( y = giTerminal_Height - 1; y -- && msg; msg = msg->Next)
 534         {
 535                  int    msglen = strlen(msg->Data);
 536                  int    prefix_len = 3 + strlen(msg->Source);
 537                  int    line_avail = giTerminal_Width - prefix_len;
 538                  int    i = 0, done = 0;
 539
 540                 y -= msglen / line_avail;       // Extra lines (y-- above handles the 1 line case)
 541                 SetCursorPos(y, 0);
 542                 printf("[%s] ", msg->Source);
 543
 544                 while(done < msglen) {
 545                         done += printf("%.*s", line_avail, msg->Data+done);
 546                         i ++;
 547                         SetCursorPos(y+i, prefix_len);
 548                 }
 549         }
 550
 551         // Bottom line is rendered by the prompt
 552 }
 553
 554 void Cmd_PRIVMSG(tServer *Server, const char *Dest, const char *Src, const char *Message)
 555 {
 556         Message_Append(Server, MSG_TYPE_STANDARD, Dest, Src, Message);
 557         //printf("<%s:%s:%s> %s\n", Server->Name, Dest, Src, Message);
 558 }
 559
 560 /**
 561  */
 562 void ParseServerLine(tServer *Server, char *Line)
 563 {
 564          int    pos = 0;
 565         char    *ident, *cmd;
 566
 567 //      _SysDebug("[%s] %s", Server->Name, Line);
 568
 569         // Message?
 570         if( *Line == ':' )
 571         {
 572                 pos ++;
 573                 ident = GetValue(Line, &pos);   // Ident (user or server)
 574                 cmd = GetValue(Line, &pos);
 575
 576                 // Numeric command
 577                 if( isdigit(cmd[0]) && isdigit(cmd[1]) && isdigit(cmd[2]) )
 578                 {
 579                         char    *user, *message;
 580                          int    num;
 581                         num  = (cmd[0] - '0') * 100;
 582                         num += (cmd[1] - '0') * 10;
 583                         num += (cmd[2] - '0') * 1;
 584
 585                         user = GetValue(Line, &pos);
 586
 587                         if( Line[pos] == ':' ) {
 588                                 message = Line + pos + 1;
 589                         }
 590                         else {
 591                                 message = GetValue(Line, &pos);
 592                         }
 593
 594                         switch(num)
 595                         {
 596                         case 332:       // Topic
 597                                 user = message; // Channel
 598                                 message = Line + pos + 1;       // Topic
 599                                 Message_AppendF(Server, MSG_TYPE_SERVER, user, user, "Topic: %s", message);
 600                                 break;
 601                         case 333:       // Topic set by
 602                                 user = message; // Channel
 603                                 message = GetValue(Line, &pos); // User
 604                                 GetValue(Line, &pos);   // Timestamp
 605                                 Message_AppendF(Server, MSG_TYPE_SERVER, user, user, "Set by %s", message);
 606                                 break;
 607                         case 353:       // /NAMES list
 608                                 // <user> = <channel> :list
 609                                 // '=' was eaten in and set to message
 610                                 user = GetValue(Line, &pos);    // Actually channel
 611                                 message = Line + pos + 1;       // List
 612                                 Message_AppendF(Server, MSG_TYPE_SERVER, user, user, "Names: %s", message);
 613                                 break;
 614                         case 366:       // end of /NAMES list
 615                                 // <user> <channel> :msg
 616                                 user = message;
 617                                 message = Line + pos + 1;
 618                                 Message_Append(Server, MSG_TYPE_SERVER, user, user, message);
 619                                 break;
 620                         case 372:       // MOTD Data
 621                         case 375:       // MOTD Start
 622                         case 376:       // MOTD End
 623
 624                         default:
 625                                 //printf("[%s] %i %s\n", Server->Name, num, message);
 626                                 Message_Append(Server, MSG_TYPE_SERVER, ident, user, message);
 627                                 break;
 628                         }
 629                 }
 630                 else if( strcmp(cmd, "NOTICE") == 0 )
 631                 {
 632                         char    *class, *message;
 633
 634                         class = GetValue(Line, &pos);
 635                         _SysDebug("NOTICE class='%s'", class);
 636
 637                         if( Line[pos] == ':' ) {
 638                                 message = Line + pos + 1;
 639                         }
 640                         else {
 641                                 message = GetValue(Line, &pos);
 642                         }
 643
 644                         //printf("[%s] NOTICE %s: %s\n", Server->Name, ident, message);
 645                         char *ident_bang = strchr(ident, '!');
 646                         if( ident_bang ) {
 647                                 *ident_bang = '\0';
 648                         }
 649                         Message_Append(Server, MSG_TYPE_NOTICE, ident, "", message);
 650                 }
 651                 else if( strcmp(cmd, "PRIVMSG") == 0 )
 652                 {
 653                         char    *dest, *message;
 654                         dest = GetValue(Line, &pos);
 655
 656                         if( Line[pos] == ':' ) {
 657                                 message = Line + pos + 1;
 658                         }
 659                         else {
 660                                 message = GetValue(Line, &pos);
 661                         }
 662
 663                         // TODO: Catch when the privmsg is addressed to the user
 664
 665 //                      Cmd_PRIVMSG(Server, dest, ident, message);
 666                         char *ident_bang = strchr(ident, '!');
 667                         if( ident_bang ) {
 668                                 *ident_bang = '\0';
 669                         }
 670                         Message_Append(Server, MSG_TYPE_STANDARD, ident, dest, message);
 671                 }
 672                 else if( strcmp(cmd, "JOIN" ) == 0 )
 673                 {
 674                         char    *channel;
 675                         channel = Line + pos + 1;
 676                         Window_Create(Server, channel);
 677                 }
 678                 else
 679                 {
 680                         Message_AppendF(Server, MSG_TYPE_SERVER, "", "", "Unknown message %s (%s)\n", cmd, Line+pos);
 681                 }
 682         }
 683         else {
 684                 cmd = GetValue(Line, &pos);
 685
 686                 if( strcmp(cmd, "PING") == 0 ) {
 687                         writef(Server->FD, "PONG %s\n", gsHostname);
 688
 689                 }
 690                 else {
 691                         // Command to client
 692                         Message_AppendF(NULL, MSG_TYPE_UNK, "", "", "Client Command: %s", Line);
 693                 }
 694         }
 695 }
 696
 697 /**
 698  * \brief Process incoming lines from the server
 699  */
 700 int ProcessIncoming(tServer *Server)
 701 {
 702         char    *ptr, *newline;
 703          int    len;
 704
 705         // While there is data in the buffer, read it into user memory and
 706         // process it line by line
 707         // ioctl#8 on a TCP client gets the number of bytes in the recieve buffer
 708         // - Used to avoid blocking
 709         #if NON_BLOCK_READ
 710         while( (len = _SysIOCtl(Server->FD, 8, NULL)) > 0 )
 711         {
 712         #endif
 713                 // Read data
 714                 len = _SysRead(Server->FD, &Server->InBuf[Server->ReadPos], BUFSIZ - Server->ReadPos);
 715                 if( len == -1 ) {
 716                         return -1;
 717                 }
 718                 Server->InBuf[Server->ReadPos + len] = '\0';
 719
 720                 // Break into lines
 721                 ptr = Server->InBuf;
 722                 while( (newline = strchr(ptr, '\n')) )
 723                 {
 724                         *newline = '\0';
 725                         if( newline[-1] == '\r' )       newline[-1] = '\0';
 726                         ParseServerLine(Server, ptr);
 727                         ptr = newline + 1;
 728                 }
 729
 730                 // Handle incomplete lines
 731                 if( ptr - Server->InBuf < len + Server->ReadPos ) {
 732                         // Update the read position
 733                         // InBuf ReadPos    ptr          ReadPos+len
 734                         // | old | new used | new unused |
 735                         Server->ReadPos = len + Server->ReadPos - (ptr - Server->InBuf);
 736                         // Copy stuff back (moving "new unused" to the start of the buffer)
 737                         memcpy(Server->InBuf, ptr, Server->ReadPos);
 738                 }
 739                 else {
 740                         Server->ReadPos = 0;
 741                 }
 742         #if NON_BLOCK_READ
 743         }
 744         #endif
 745
 746         return 0;
 747 }
 748
 749 /**
 750  * \brief Write a formatted string to a file descriptor
 751  *
 752  */
 753 int writef(int FD, const char *Format, ...)
 754 {
 755         va_list args;
 756          int    len;
 757
 758         va_start(args, Format);
 759         len = vsnprintf(NULL, 0, Format, args);
 760         va_end(args);
 761
 762         {
 763                 char    buf[len+1];
 764                 va_start(args, Format);
 765                 vsnprintf(buf, len+1, Format, args);
 766                 va_end(args);
 767
 768                 return _SysWrite(FD, buf, len);
 769         }
 770 }
 771
 772 /**
 773  * \brief Initialise a TCP connection to \a AddressString on port \a PortNumber
 774  */
 775 int OpenTCP(const char *AddressString, short PortNumber)
 776 {
 777          int    fd, addrType;
 778         char    addrBuffer[8];
 779
 780         // Parse IP Address
 781         addrType = Net_ParseAddress(AddressString, addrBuffer);
 782         if( addrType == 0 ) {
 783                 fprintf(stderr, "Unable to parse '%s' as an IP address\n", AddressString);
 784                 _SysDebug("Unable to parse '%s' as an IP address\n", AddressString);
 785                 return -1;
 786         }
 787
 788         // Finds the interface for the destination address
 789         fd = Net_OpenSocket(addrType, addrBuffer, "tcpc");
 790         if( fd == -1 ) {
 791                 fprintf(stderr, "Unable to open TCP Client to '%s'\n", AddressString);
 792                 _SysDebug("Unable to open TCP client to '%s'\n", AddressString);
 793                 return -1;
 794         }
 795
 796         // Set remote port and address
 797 //      printf("Setting port and remote address\n");
 798         _SysIOCtl(fd, 5, &PortNumber);
 799         _SysIOCtl(fd, 6, addrBuffer);
 800
 801         // Connect
 802 //      printf("Initiating connection\n");
 803         if( _SysIOCtl(fd, 7, NULL) == 0 ) {
 804                 // Shouldn't happen :(
 805                 fprintf(stderr, "Unable to start connection\n");
 806                 return -1;
 807         }
 808
 809         // Return descriptor
 810         return fd;
 811 }
 812
 813 /**
 814  * \brief Read a space-separated value from a string
 815  */
 816 char *GetValue(char *Src, int *Ofs)
 817 {
 818          int    pos = *Ofs;
 819         char    *ret = Src + pos;
 820         char    *end;
 821
 822         if( !Src )      return NULL;
 823
 824         while( *ret == ' ' )    ret ++;
 825
 826         end = strchr(ret, ' ');
 827         if( end ) {
 828                 *end = '\0';
 829         }
 830         else {
 831                 end = ret + strlen(ret) - 1;
 832         }
 833
 834         end ++ ;
 835         while( *ret == ' ' )    end ++;
 836         *Ofs = end - Src;
 837
 838         return ret;
 839 }
 840
 841 void SetCursorPos(int Row, int Col)
 842 {
 843         printf("\x1B[%i;%iH", Row, Col);
 844 }
 845
 846 static inline int isdigit(int ch)
 847 {
 848         return '0' <= ch && ch < '9';
 849 }