mdw@git.distorted.org.uk Git - bascat/blob - bascat.c

   1 /* -*-c-*-
   2  *
   3  * $Id: bascat.c,v 1.1 1998/03/16 15:21:37 mdw Exp $
   4  *
   5  * Display BBC BASIC programs more or less anywhere
   6  *
   7  * (c) 1996, 1997 Matthew Wilcox and Mark Wooding
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of Bascat.
  13  *
  14  * Bascat is free software; you can redistribute it and/or modify it
  15  * under the terms of the GNU Library General Public License as
  16  * published by the Free Software Foundation; either version 2 of the
  17  * License, or (at your option) any later version.
  18  *
  19  * Bascat is distributed in the hope that it will be useful, but
  20  * WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU Library General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with Bascat; if not, write to the Free Software Foundation,
  26  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  27  */
  28
  29 /*----- Revision history --------------------------------------------------*
  30  *
  31  * $Log: bascat.c,v $
  32  * Revision 1.1  1998/03/16 15:21:37  mdw
  33  * Files placed under CVS control.
  34  *
  35  * Revision 1.1  1997/07/23 01:19:33  mdw
  36  * Initial revision
  37  *
  38  */
  39
  40 /*----- Header files ------------------------------------------------------*/
  41
  42 /* --- ANSI library headers --- */
  43
  44 #include <ctype.h>
  45 #include <errno.h>
  46 #include <signal.h>
  47 #include <stdio.h>
  48 #include <stdlib.h>
  49 #include <string.h>
  50
  51 /* --- Operating system specific headers --- */
  52
  53 #ifdef HAVE_LIBTERMCAP
  54 #  include <termcap.h>
  55 #endif
  56 #include <unistd.h>
  57
  58 /* --- Private headers --- */
  59
  60 #include "mdwopt.h"
  61
  62 /*----- Version information -----------------------------------------------*/
  63
  64 #ifndef NDEBUG
  65 #  define D(x) x
  66 #else
  67 #  define D(x)
  68 #endif
  69
  70 /*----- Tokenisation tables -----------------------------------------------*
  71  *
  72  * These tables are from the BBC BASIC guide.  Additional verification
  73  * carried out on an A440 with RISC OS 3.1
  74  */
  75
  76 static const char *bcTok__base[] = {
  77   "OTHERWISE",
  78   "AND", "DIV", "EOR", "MOD", "OR", "ERROR", "LINE", "OFF",
  79   "STEP", "SPC", "TAB(", "ELSE", "THEN", "*", "OPENIN", "PTR",
  80   "PAGE", "TIME", "LOMEM", "HIMEM", "ABS", "ACS", "ADVAL", "ASC",
  81   "ASN", "ATN", "BGET", "COS", "COUNT", "DEG", "ERL", "ERR",
  82   "EVAL", "EXP", "EXT", "FALSE", "FN", "GET", "INKEY", "INSTR(",
  83   "INT", "LEN", "LN", "LOG", "NOT", "OPENUP", "OPENOUT", "PI",
  84   "POINT(", "POS", "RAD", "RND", "SGN", "SIN", "SQR", "TAN",
  85   "TO", "TRUE", "USR", "VAL", "VPOS", "CHR$", "GET$", "INKEY$",
  86   "LEFT$(", "MID$(", "RIGHT$(", "STR$", "STRING$(", "EOF", "*", "*",
  87   "*", "WHEN", "OF", "ENDCASE", "ELSE", "ENDIF", "ENDWHILE", "PTR",
  88   "PAGE", "TIME", "LOMEM", "HIMEM", "SOUND", "BPUT", "CALL", "CHAIN",
  89   "CLEAR", "CLOSE", "CLG", "CLS", "DATA", "DEF", "DIM", "DRAW",
  90   "END", "ENDPROC", "ENVELOPE", "FOR", "GOSUB", "GOTO", "GCOL", "IF",
  91   "INPUT", "LET", "LOCAL", "MODE", "MOVE", "NEXT", "ON", "VDU",
  92   "PLOT", "PRINT", "PROC", "READ", "REM", "REPEAT", "REPORT", "RESTORE",
  93   "RETURN", "RUN", "STOP", "COLOUR", "TRACE", "UNTIL", "WIDTH", "OSCLI"
  94 };
  95
  96 static const char *bcTok__c6[] = {
  97   "SUM", "BEAT"
  98 };
  99
 100 static const char *bcTok__c7[] = {
 101   "APPEND", "AUTO",
 102   "CRUNCH", "DELETE", "EDIT", "HELP", "LIST", "LOAD", "LVAR", "NEW",
 103   "OLD", "RENUMBER", "SAVE", "TEXTLOAD", "TEXTSAVE", "TWIN", "TWINO",
 104     "INSTALL"
 105 };
 106
 107 static const char *bcTok__c8[] = {
 108   "CASE", "CIRCLE",
 109   "FILL", "ORIGIN", "POINT", "RECTANGLE", "SWAP", "WHILE", "WAIT", "MOUSE",
 110   "QUIT", "SYS", "INSTALL", "LIBRARY", "TINT", "ELLIPSE", "BEATS", "TEMPO",
 111   "VOICES", "VOICE", "STEREO", "OVERLAY"
 112 };
 113
 114 #define ITEMS(array) (sizeof(array) / sizeof((array)[0]))
 115
 116 /*----- Static variables --------------------------------------------------*/
 117
 118 enum {
 119   s_keyword,                            /* Expecting a keyword next */
 120   s_normal,                             /* Normal state, reading input */
 121   s_comment,                            /* In a command (or literal *cmd) */
 122   s_quote,                              /* Inside a quoted string */
 123   s_c6, s_c7, s_c8,                     /* Various shift states */
 124   s_dummy
 125 };
 126
 127 static bc__state = s_normal;            /* Current detokenisation state */
 128
 129 enum {
 130   f_highlight = 1,                      /* Highlight keywords and things */
 131   f_linenumbers = 2,                    /* Display linenumbers on left */
 132   f_tty = 4,                            /* We're writing to TTY (or pager) */
 133   f_less = 8,                           /* We're piping through `less' */
 134   f_dummy
 135 };
 136
 137 static int bc__flags;                   /* Various options flags */
 138
 139 #ifdef HAVE_LIBTERMCAP
 140 static char bc__termcap[2048];          /* Terminal capabilities buffer */
 141 #endif
 142
 143 static char *bc__pager = 0;             /* Pointer to pager to use */
 144
 145 /*----- Main code ---------------------------------------------------------*/
 146
 147 /* --- @die@ --- *
 148  *
 149  * Arguments:   @char *p@ = pointer to a string
 150  *
 151  * Returns:     1
 152  *
 153  * Use:         Reports an error to the user and falls over flat on its face.
 154  */
 155
 156 static int die(const char *p)
 157 {
 158   fprintf(stderr, "%s: %s\n", optprog, p);
 159   return (1);
 160 }
 161
 162 /* --- @bc__keyword@ --- *
 163  *
 164  * Arguments:   @char *s@ = pointer to keyword string
 165  *              @FILE *fp@ = stream to write onto
 166  *
 167  * Returns:     --
 168  *
 169  * Use:         Displays a keyword in a nice way.  There's some nasty hacking
 170  *              here to make GNU's `less' work properly.  `more' appears to
 171  *              cope with highlighting codes OK, so that's fine.  `less'
 172  *              prefers it if we attempt to `overstrike' the bolded
 173  *              characters.  What fun...
 174  */
 175
 176 static void bc__keyword(const char *s, FILE *fp)
 177 {
 178 #ifdef HAVE_LIBTERMCAP
 179   if ((~bc__flags & (f_less | f_highlight)) == 0) {
 180     while (*s) {
 181       putc(*s, fp);
 182       putc(8, fp);                      /* evil... */
 183       putc(*s, fp);
 184       s++;
 185     }
 186   } else {
 187     static char buff[24];
 188     static char *hs, *he, *p = buff;
 189
 190     if (!hs) {
 191       if (bc__flags & f_highlight) {
 192         hs = tgetstr("md", &p);
 193         he = tgetstr("me", &p);
 194       } else
 195         hs = he = "";
 196     }
 197     fputs(hs, fp);
 198     fputs(s, fp);
 199     fputs(he, fp);
 200   }
 201 #else
 202   fputs(s, fp);
 203 #endif
 204 }
 205
 206 /* --- @bc__mbtok@ --- *
 207  *
 208  * Arguments:   @int byte@ = the current byte
 209  *              @const char *t[]@ = pointer to token table
 210  *              @int n@ = number of items in token table
 211  *              @FILE *fp@ = stream to write onto
 212  *
 213  * Returns:     0 if everything's OK
 214  *
 215  * Use:         Decodes multibyte tokens.
 216  */
 217
 218 static int bc__mbtok(int byte, const char *t[], int n, FILE * fp)
 219 {
 220   byte -= 0x8E;
 221   if (byte >= n)
 222     return (die("Bad program: invalid multibyte token"));
 223   bc__keyword(t[byte], fp);
 224   bc__state = s_normal;
 225   return (0);
 226 }
 227
 228 /* --- @bc__decode@ --- *
 229  *
 230  * Arguments:   @int byte@ = byte to decode
 231  *              @FILE *fp@ = stream to write onto
 232  *
 233  * Returns:     0 if everything's going OK
 234  *
 235  * Use:         Decodes a byte, changing states as necessary.
 236  */
 237
 238 static int bc__decode(int byte, FILE * fp)
 239 {
 240   switch (bc__state) {
 241     case s_keyword:
 242       if (byte == '*')
 243         bc__state = s_comment;
 244       else
 245         bc__state = s_normal;
 246       /* Fall through here */
 247     case s_normal:
 248       if (byte >= 0x7F) {
 249         switch (byte) {
 250           case 0xC6:
 251             bc__state = s_c6;
 252             break;
 253           case 0xC7:
 254             bc__state = s_c7;
 255             break;
 256           case 0xC8:
 257             bc__state = s_c8;
 258             break;
 259           case 0x8B:                    /* ELSE */
 260           case 0x8C:                    /* THEN */
 261           case 0xF5:                    /* REPEAT (a funny one) */
 262             bc__state = s_keyword;
 263             bc__keyword(bcTok__base[byte - 0x7F], fp);
 264             break;
 265           case 0xDC:                    /* DATA */
 266           case 0xF4:                    /* REM */
 267             bc__state = s_comment;
 268             /* Fall through here */
 269           default:
 270             bc__keyword(bcTok__base[byte - 0x7F], fp);
 271             break;
 272         }
 273       } else {
 274         if (byte == '"')
 275           bc__state = s_quote;
 276         fputc(byte, fp);
 277       }
 278       break;
 279     case s_quote:
 280       if (byte == '"')
 281         bc__state = s_normal;
 282       /* Fall through here */
 283     case s_comment:
 284       fputc(byte, fp);
 285       break;
 286     case s_c6:
 287       return (bc__mbtok(byte, bcTok__c6, ITEMS(bcTok__c6), fp));
 288       break;
 289     case s_c7:
 290       return (bc__mbtok(byte, bcTok__c7, ITEMS(bcTok__c7), fp));
 291       break;
 292     case s_c8:
 293       return (bc__mbtok(byte, bcTok__c8, ITEMS(bcTok__c8), fp));
 294       break;
 295   }
 296   return (0);
 297 }
 298
 299 /* --- @bc__line@ --- *
 300  *
 301  * Arguments:   @FILE *in@ = input stream to read
 302  *              @FILE *out@ = output stream to write
 303  *
 304  * Returns:     Zero if there's another line after this one.
 305  *
 306  * Use:         Decodes a BASIC line into stuff to be written.
 307  */
 308
 309 static int bc__line(FILE *in, FILE *out)
 310 {
 311   /* --- Read the line number --- */
 312
 313   {
 314     int a, b;
 315
 316     a = getc(in);
 317     D( fprintf(stderr, "ln_0 == %i\n", a); )
 318       if (a == EOF)
 319       goto eof;
 320     if (a == 0xFF)
 321       return (1);
 322
 323     b = getc(in);
 324     D( fprintf(stderr, "ln_1 == %i\n", b); )
 325       if (b == EOF)
 326       goto eof;
 327
 328     if (bc__flags & f_linenumbers)
 329       fprintf(out, "%5i", (a << 8) + b);
 330   }
 331
 332   {
 333     int len;
 334     int byte;
 335
 336     len = getc(in);
 337     D( fprintf(stderr, "linelen == %i\n", len); )
 338       if (len == EOF)
 339       goto eof;
 340     len -= 4;
 341
 342     bc__state = s_normal;
 343     while (len) {
 344       byte = getc(in);
 345       D( fprintf(stderr, "state == %i, byte == %i\n", \
 346                 bc__state, byte); )
 347         if (byte == EOF)
 348         goto eof;
 349       bc__decode(byte, out);
 350       len--;
 351     }
 352     putc('\n', out);
 353
 354     byte = getc(in);
 355     D( fprintf(stderr, "eol == %i\n", byte); )
 356       if (byte == EOF)
 357       goto eof;
 358     else if (byte != 0x0D)
 359       return (die("Bad program: expected end-of-line delimiter"));
 360   }
 361
 362   return (0);
 363
 364 eof:
 365   return (die("Bad program: unexpected end-of-file"));
 366 }
 367
 368 /* --- @bc__file@ --- *
 369  *
 370  * Arguments:   @FILE *in@ = the input stream
 371  *              @FILE *out@ = the output stream
 372  *
 373  * Returns:     --
 374  *
 375  * Use:         Decodes an entire file.
 376  */
 377
 378 static void bc__file(FILE *in, FILE *out)
 379 {
 380   int byte;
 381
 382   /* --- Check for the inital newline char --- */
 383
 384   byte = getc(in);
 385   if (byte != 0x0D)
 386     die("Bad program: doesn't start with a newline");
 387
 388   /* --- Now read the lines in one by one --- */
 389
 390   while (!bc__line(in, out)) ;
 391
 392   /* --- Check that we're really at end-of-file --- */
 393
 394   byte = getc(in);
 395   if (byte != EOF)
 396     die("Found data after end of program");
 397 }
 398
 399 /* --- @bc__sigPipe@ --- *
 400  *
 401  * Arguments:   @int s@ = signal number
 402  *
 403  * Returns:     Doesn't
 404  *
 405  * Use:         Handles SIGPIPE signals, and gracefully kills the program.
 406  */
 407
 408 static void bc__sigPipe(int s)
 409 {
 410   (void) s;
 411   exit(0);                              /* Gracefully, oh yes */
 412 }
 413
 414 /* --- @bc__options@ --- *
 415  *
 416  * Arguments:   @int c@ = number of arguments
 417  *              @char *v[]@ = pointer to arguments
 418  *              @char *s@ = pointer to short options
 419  *              @struct option *o@ = pointer to long options
 420  *
 421  * Returns:     --
 422  *
 423  * Use:         Parses lots of arguments.
 424  */
 425
 426 static void bc__options(int c, char *v[], const char *s,
 427                         const struct option *o)
 428 {
 429   int i;
 430
 431   for (;;) {
 432     i = mdwopt(c, v, s, o, 0, 0, gFlag_negation | gFlag_envVar);
 433     if (i == -1)
 434       break;
 435
 436     switch (i) {
 437       case 'v':
 438       case 'h':
 439         printf("%s v. " VERSION " (" __DATE__ ")\n", optprog);
 440         if (i == 'v')
 441           exit(0);
 442         printf("\n"
 443                "%s [-hv] [-n|+n] [-l|+l] [-p PAGER] [file...]\n"
 444                "\n"
 445                "Types BBC BASIC programs in a readable way.  Options "
 446                "currently supported are as\n"
 447                "follows:\n"
 448                "\n"
 449                "-h, --help:            Displays this evil help message\n"
 450                "-v, --version:         Displays the current version number\n"
 451                "-n, --line-numbers:    Displays line numbers for each line\n"
 452                "-l, --highlight:       Attempts to highlight keywords\n"
 453                "-p, --pager=PAGER:     Sets pager to use (default $PAGER)\n"
 454                "\n"
 455                "Prefix long options with `no-' to cancel them.  Use `+' to "
 456                "cancel short options.\n"
 457                "Options can also be placed in the `BASCAT' environment "
 458                "variable, if you don't\n"
 459                "like the standard settings.\n",
 460                optprog);
 461         exit(0);
 462         break;
 463       case 'n':
 464         bc__flags |= f_linenumbers;
 465         break;
 466       case 'n' | gFlag_negated:
 467         bc__flags &= ~f_linenumbers;
 468         break;
 469       case 'l':
 470         bc__flags |= f_highlight;
 471         break;
 472       case 'l' | gFlag_negated:
 473         bc__flags &= ~f_highlight;
 474         break;
 475       case 'p':
 476         bc__pager = optarg;
 477         break;
 478     }
 479   }
 480 }
 481
 482 /* --- @main@ --- *
 483  *
 484  * Arguments:   @int argc@ = number of arguments
 485  *              @char *argc[]@ = pointer to what the arguments are
 486  *
 487  * Returns:     0 if it all worked
 488  *
 489  * Use:         Displays BASIC programs.
 490  */
 491
 492 int main(int argc, char *argv[])
 493 {
 494   static struct option opts[] = {
 495     { "help", 0, 0, 'h' },
 496     { "version", 0, 0, 'v' },
 497     { "line-numbers", gFlag_negate, 0, 'n' },
 498     { "highlight", gFlag_negate, 0, 'l' },
 499     { "pager", gFlag_argReq, 0, 'p' },
 500     { 0, 0, 0, 0 }
 501   };
 502   static char *shortopts = "hvn+l+p:";
 503
 504   /* --- Parse the command line options --- */
 505
 506   bc__options(argc, argv, shortopts, opts);
 507
 508   /* --- Now do the job --- */
 509
 510   if (optind == argc && isatty(0)) {
 511     fprintf(stderr,
 512             "%s: No filenames given, and standard input is a tty\n"
 513             "To force reading from stdin, use `%s -'.  For help, type "
 514             "`%s --help'.\n",
 515             optprog, optprog, optprog);
 516     exit(0);
 517   }
 518
 519 #ifdef HAVE_LIBTERMCAP
 520   if (bc__flags & f_highlight)
 521     tgetent(bc__termcap, getenv("TERM"));
 522 #endif
 523
 524   {
 525     FILE *in;
 526     FILE *out;
 527
 528     /* --- If output is to a terminal, try paging --- *
 529      *
 530      * All programs which spew text should do this ;-)
 531      */
 532
 533     if (isatty(1)) {
 534       if (!bc__pager)
 535         bc__pager = getenv("PAGER");
 536       if (!bc__pager)
 537         bc__pager = PAGER;              /* Worth a try */
 538       if (strstr(bc__pager, "less"))
 539         bc__flags |= f_less;            /* HACK!!! */
 540       out = popen(bc__pager, "w");
 541       if (!out)
 542         out = stdout;
 543       else {
 544         bc__flags |= f_tty;
 545         signal(SIGPIPE, bc__sigPipe);
 546       }
 547     } else
 548       out = stdout;
 549
 550     /* --- Now go through all the files --- */
 551
 552     if (optind == argc)
 553       bc__file(stdin, out);
 554     else
 555       while (optind < argc) {
 556         if (strcmp(argv[optind], "-") == 0)
 557           bc__file(stdin, out);
 558         else {
 559           in = fopen(argv[optind], "rb");
 560           if (!in) {
 561             fprintf(stderr,
 562                     "%s: Couldn't open input file: %s\n",
 563                     optprog, strerror(errno));
 564           } else {
 565             bc__file(in, out);
 566             fclose(in);
 567           }
 568         }
 569         optind++;
 570       }
 571     if (bc__flags & f_tty)
 572       pclose(out);
 573   }
 574
 575   return (0);
 576 }
 577
 578 /*----- That's all, folks -------------------------------------------------*/