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

   1 /* -*-c-*-
   2  *
   3  * $Id: bascat.c,v 1.2 1998/06/26 11:29:28 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 1.2  1998/06/26 11:29:28  mdw
  33  * Added support for line-numbers.
  34  *
  35  * Revision 1.1  1998/03/16 15:21:37  mdw
  36  * Files placed under CVS control.
  37  *
  38  * Revision 1.1  1997/07/23 01:19:33  mdw
  39  * Initial revision
  40  *
  41  */
  42
  43 /*----- Header files ------------------------------------------------------*/
  44
  45 /* --- ANSI library headers --- */
  46
  47 #include <ctype.h>
  48 #include <errno.h>
  49 #include <signal.h>
  50 #include <stdio.h>
  51 #include <stdlib.h>
  52 #include <string.h>
  53
  54 /* --- Operating system specific headers --- */
  55
  56 #ifdef HAVE_LIBTERMCAP
  57 #  include <termcap.h>
  58 #endif
  59 #include <unistd.h>
  60
  61 /* --- Private headers --- */
  62
  63 #include "mdwopt.h"
  64
  65 /*----- Version information -----------------------------------------------*/
  66
  67 #ifndef NDEBUG
  68 #  define D(x) x
  69 #else
  70 #  define D(x)
  71 #endif
  72
  73 /*----- Tokenisation tables -----------------------------------------------*
  74  *
  75  * These tables are from the BBC BASIC guide.  Additional verification
  76  * carried out on an A440 with RISC OS 3.1
  77  */
  78
  79 static const char *bcTok__base[] = {
  80   "OTHERWISE",
  81   "AND", "DIV", "EOR", "MOD", "OR", "ERROR", "LINE", "OFF",
  82   "STEP", "SPC", "TAB(", "ELSE", "THEN", "*", "OPENIN", "PTR",
  83   "PAGE", "TIME", "LOMEM", "HIMEM", "ABS", "ACS", "ADVAL", "ASC",
  84   "ASN", "ATN", "BGET", "COS", "COUNT", "DEG", "ERL", "ERR",
  85   "EVAL", "EXP", "EXT", "FALSE", "FN", "GET", "INKEY", "INSTR(",
  86   "INT", "LEN", "LN", "LOG", "NOT", "OPENUP", "OPENOUT", "PI",
  87   "POINT(", "POS", "RAD", "RND", "SGN", "SIN", "SQR", "TAN",
  88   "TO", "TRUE", "USR", "VAL", "VPOS", "CHR$", "GET$", "INKEY$",
  89   "LEFT$(", "MID$(", "RIGHT$(", "STR$", "STRING$(", "EOF", "*", "*",
  90   "*", "WHEN", "OF", "ENDCASE", "ELSE", "ENDIF", "ENDWHILE", "PTR",
  91   "PAGE", "TIME", "LOMEM", "HIMEM", "SOUND", "BPUT", "CALL", "CHAIN",
  92   "CLEAR", "CLOSE", "CLG", "CLS", "DATA", "DEF", "DIM", "DRAW",
  93   "END", "ENDPROC", "ENVELOPE", "FOR", "GOSUB", "GOTO", "GCOL", "IF",
  94   "INPUT", "LET", "LOCAL", "MODE", "MOVE", "NEXT", "ON", "VDU",
  95   "PLOT", "PRINT", "PROC", "READ", "REM", "REPEAT", "REPORT", "RESTORE",
  96   "RETURN", "RUN", "STOP", "COLOUR", "TRACE", "UNTIL", "WIDTH", "OSCLI"
  97 };
  98
  99 static const char *bcTok__c6[] = {
 100   "SUM", "BEAT"
 101 };
 102
 103 static const char *bcTok__c7[] = {
 104   "APPEND", "AUTO",
 105   "CRUNCH", "DELETE", "EDIT", "HELP", "LIST", "LOAD", "LVAR", "NEW",
 106   "OLD", "RENUMBER", "SAVE", "TEXTLOAD", "TEXTSAVE", "TWIN", "TWINO",
 107     "INSTALL"
 108 };
 109
 110 static const char *bcTok__c8[] = {
 111   "CASE", "CIRCLE",
 112   "FILL", "ORIGIN", "POINT", "RECTANGLE", "SWAP", "WHILE", "WAIT", "MOUSE",
 113   "QUIT", "SYS", "INSTALL", "LIBRARY", "TINT", "ELLIPSE", "BEATS", "TEMPO",
 114   "VOICES", "VOICE", "STEREO", "OVERLAY"
 115 };
 116
 117 #define ITEMS(array) (sizeof(array) / sizeof((array)[0]))
 118
 119 /*----- Static variables --------------------------------------------------*/
 120
 121 enum {
 122   s_keyword,                            /* Expecting a keyword next */
 123   s_normal,                             /* Normal state, reading input */
 124   s_comment,                            /* In a command (or literal *cmd) */
 125   s_quote,                              /* Inside a quoted string */
 126   s_c6, s_c7, s_c8,                     /* Various shift states */
 127   s_linex, s_liney, s_linez,            /* Line number states */
 128   s_dummy
 129 };
 130
 131 static int bc__state = s_normal;        /* Current detokenisation state */
 132 static unsigned int bc__lineno;         /* Line number */
 133
 134 enum {
 135   f_highlight = 1,                      /* Highlight keywords and things */
 136   f_linenumbers = 2,                    /* Display linenumbers on left */
 137   f_tty = 4,                            /* We're writing to TTY (or pager) */
 138   f_less = 8,                           /* We're piping through `less' */
 139   f_dummy
 140 };
 141
 142 static int bc__flags;                   /* Various options flags */
 143
 144 #ifdef HAVE_LIBTERMCAP
 145 static char bc__termcap[2048];          /* Terminal capabilities buffer */
 146 #endif
 147
 148 static char *bc__pager = 0;             /* Pointer to pager to use */
 149
 150 /*----- Main code ---------------------------------------------------------*/
 151
 152 /* --- @die@ --- *
 153  *
 154  * Arguments:   @char *p@ = pointer to a string
 155  *
 156  * Returns:     1
 157  *
 158  * Use:         Reports an error to the user and falls over flat on its face.
 159  */
 160
 161 static int die(const char *p)
 162 {
 163   fprintf(stderr, "%s: %s\n", optprog, p);
 164   return (1);
 165 }
 166
 167 /* --- @bc__keyword@ --- *
 168  *
 169  * Arguments:   @char *s@ = pointer to keyword string
 170  *              @FILE *fp@ = stream to write onto
 171  *
 172  * Returns:     --
 173  *
 174  * Use:         Displays a keyword in a nice way.  There's some nasty hacking
 175  *              here to make GNU's `less' work properly.  `more' appears to
 176  *              cope with highlighting codes OK, so that's fine.  `less'
 177  *              prefers it if we attempt to `overstrike' the bolded
 178  *              characters.  What fun...
 179  */
 180
 181 static void bc__keyword(const char *s, FILE *fp)
 182 {
 183 #ifdef HAVE_LIBTERMCAP
 184   if ((~bc__flags & (f_less | f_highlight)) == 0) {
 185     while (*s) {
 186       putc(*s, fp);
 187       putc(8, fp);                      /* evil... */
 188       putc(*s, fp);
 189       s++;
 190     }
 191   } else {
 192     static char buff[24];
 193     static char *hs, *he, *p = buff;
 194
 195     if (!hs) {
 196       if (bc__flags & f_highlight) {
 197         hs = tgetstr("md", &p);
 198         he = tgetstr("me", &p);
 199       } else
 200         hs = he = "";
 201     }
 202     fputs(hs, fp);
 203     fputs(s, fp);
 204     fputs(he, fp);
 205   }
 206 #else
 207   fputs(s, fp);
 208 #endif
 209 }
 210
 211 /* --- @bc__mbtok@ --- *
 212  *
 213  * Arguments:   @int byte@ = the current byte
 214  *              @const char *t[]@ = pointer to token table
 215  *              @int n@ = number of items in token table
 216  *              @FILE *fp@ = stream to write onto
 217  *
 218  * Returns:     0 if everything's OK
 219  *
 220  * Use:         Decodes multibyte tokens.
 221  */
 222
 223 static int bc__mbtok(int byte, const char *t[], int n, FILE * fp)
 224 {
 225   byte -= 0x8E;
 226   if (byte >= n)
 227     return (die("Bad program: invalid multibyte token"));
 228   bc__keyword(t[byte], fp);
 229   bc__state = s_normal;
 230   return (0);
 231 }
 232
 233 /* --- @bc__decode@ --- *
 234  *
 235  * Arguments:   @int byte@ = byte to decode
 236  *              @FILE *fp@ = stream to write onto
 237  *
 238  * Returns:     0 if everything's going OK
 239  *
 240  * Use:         Decodes a byte, changing states as necessary.
 241  */
 242
 243 static int bc__decode(int byte, FILE * fp)
 244 {
 245   switch (bc__state) {
 246
 247     /* --- Tokenised states --- */
 248
 249     case s_keyword:
 250       if (byte == '*')
 251         bc__state = s_comment;
 252       else
 253         bc__state = s_normal;
 254       /* Fall through here */
 255
 256     case s_normal:
 257       if (byte >= 0x7F) {
 258         switch (byte) {
 259           case 0xC6:
 260             bc__state = s_c6;
 261             break;
 262           case 0xC7:
 263             bc__state = s_c7;
 264             break;
 265           case 0xC8:
 266             bc__state = s_c8;
 267             break;
 268           case 0x8D:
 269             bc__state = s_linex;
 270             break;
 271           case 0x8B:                    /* ELSE */
 272           case 0x8C:                    /* THEN */
 273           case 0xF5:                    /* REPEAT (a funny one) */
 274             bc__state = s_keyword;
 275             goto keyword;
 276             break;
 277           case 0xDC:                    /* DATA */
 278           case 0xF4:                    /* REM */
 279             bc__state = s_comment;
 280             /* Fall through here */
 281           default:
 282           keyword:
 283             bc__keyword(bcTok__base[byte - 0x7F], fp);
 284             break;
 285         }
 286       } else {
 287         if (byte == '"')
 288           bc__state = s_quote;
 289         fputc(byte, fp);
 290       }
 291       break;
 292
 293     /* --- Non-tokenised states --- */
 294
 295     case s_quote:
 296       if (byte == '"')
 297         bc__state = s_normal;
 298       /* Fall through here */
 299
 300     case s_comment:
 301       fputc(byte, fp);
 302       break;
 303
 304     /* --- Double-byte token states --- */
 305
 306     case s_c6:
 307       return (bc__mbtok(byte, bcTok__c6, ITEMS(bcTok__c6), fp));
 308       break;
 309
 310     case s_c7:
 311       return (bc__mbtok(byte, bcTok__c7, ITEMS(bcTok__c7), fp));
 312       break;
 313
 314     case s_c8:
 315       return (bc__mbtok(byte, bcTok__c8, ITEMS(bcTok__c8), fp));
 316       break;
 317
 318     /* --- Encoded line number states --- */
 319
 320     case s_linex:
 321       bc__lineno = ((((byte << 2) | (byte << 12)) & 0xc0c0u) ^ 0x4040u);
 322       bc__state++;
 323       break;
 324
 325     case s_liney:
 326       bc__lineno |= byte & 0x3fu;
 327       bc__state++;
 328       break;
 329
 330     case s_linez:
 331       bc__lineno |= (byte << 8) & 0x3fu;
 332       fprintf(fp, "%u", bc__lineno);
 333       bc__state = s_normal;
 334       break;
 335
 336   }
 337   return (0);
 338 }
 339
 340 /* --- @bc__line@ --- *
 341  *
 342  * Arguments:   @FILE *in@ = input stream to read
 343  *              @FILE *out@ = output stream to write
 344  *
 345  * Returns:     Zero if there's another line after this one.
 346  *
 347  * Use:         Decodes a BASIC line into stuff to be written.
 348  */
 349
 350 static int bc__line(FILE *in, FILE *out)
 351 {
 352   /* --- Read the line number --- */
 353
 354   {
 355     int a, b;
 356
 357     a = getc(in);
 358     D( fprintf(stderr, "ln_0 == %i\n", a); )
 359       if (a == EOF)
 360       goto eof;
 361     if (a == 0xFF)
 362       return (1);
 363
 364     b = getc(in);
 365     D( fprintf(stderr, "ln_1 == %i\n", b); )
 366       if (b == EOF)
 367       goto eof;
 368
 369     if (bc__flags & f_linenumbers)
 370       fprintf(out, "%5i", (a << 8) + b);
 371   }
 372
 373   {
 374     int len;
 375     int byte;
 376
 377     len = getc(in);
 378     D( fprintf(stderr, "linelen == %i\n", len); )
 379       if (len == EOF)
 380       goto eof;
 381     len -= 4;
 382
 383     bc__state = s_normal;
 384     while (len) {
 385       byte = getc(in);
 386       D( fprintf(stderr, "state == %i, byte == %i\n",
 387                  bc__state, byte); )
 388         if (byte == EOF)
 389         goto eof;
 390       bc__decode(byte, out);
 391       len--;
 392     }
 393     putc('\n', out);
 394
 395     byte = getc(in);
 396     D( fprintf(stderr, "eol == %i\n", byte); )
 397       if (byte == EOF)
 398       goto eof;
 399     else if (byte != 0x0D)
 400       return (die("Bad program: expected end-of-line delimiter"));
 401   }
 402
 403   return (0);
 404
 405 eof:
 406   return (die("Bad program: unexpected end-of-file"));
 407 }
 408
 409 /* --- @bc__file@ --- *
 410  *
 411  * Arguments:   @FILE *in@ = the input stream
 412  *              @FILE *out@ = the output stream
 413  *
 414  * Returns:     --
 415  *
 416  * Use:         Decodes an entire file.
 417  */
 418
 419 static void bc__file(FILE *in, FILE *out)
 420 {
 421   int byte;
 422
 423   /* --- Check for the inital newline char --- */
 424
 425   byte = getc(in);
 426   if (byte != 0x0D)
 427     die("Bad program: doesn't start with a newline");
 428
 429   /* --- Now read the lines in one by one --- */
 430
 431   while (!bc__line(in, out)) ;
 432
 433   /* --- Check that we're really at end-of-file --- */
 434
 435   byte = getc(in);
 436   if (byte != EOF)
 437     die("Found data after end of program");
 438 }
 439
 440 /* --- @bc__sigPipe@ --- *
 441  *
 442  * Arguments:   @int s@ = signal number
 443  *
 444  * Returns:     Doesn't
 445  *
 446  * Use:         Handles SIGPIPE signals, and gracefully kills the program.
 447  */
 448
 449 static void bc__sigPipe(int s)
 450 {
 451   (void) s;
 452   exit(0);                              /* Gracefully, oh yes */
 453 }
 454
 455 /* --- @bc__options@ --- *
 456  *
 457  * Arguments:   @int c@ = number of arguments
 458  *              @char *v[]@ = pointer to arguments
 459  *              @char *s@ = pointer to short options
 460  *              @struct option *o@ = pointer to long options
 461  *
 462  * Returns:     --
 463  *
 464  * Use:         Parses lots of arguments.
 465  */
 466
 467 static void bc__options(int c, char *v[], const char *s,
 468                         const struct option *o)
 469 {
 470   int i;
 471
 472   for (;;) {
 473     i = mdwopt(c, v, s, o, 0, 0, gFlag_negation | gFlag_envVar);
 474     if (i == -1)
 475       break;
 476
 477     switch (i) {
 478       case 'v':
 479       case 'h':
 480         printf("%s v. " VERSION " (" __DATE__ ")\n", optprog);
 481         if (i == 'v')
 482           exit(0);
 483         printf("\n"
 484                "%s [-hv] [-n|+n] [-l|+l] [-p PAGER] [file...]\n"
 485                "\n"
 486                "Types BBC BASIC programs in a readable way.  Options "
 487                "currently supported are as\n"
 488                "follows:\n"
 489                "\n"
 490                "-h, --help:            Displays this evil help message\n"
 491                "-v, --version:         Displays the current version number\n"
 492                "-n, --line-numbers:    Displays line numbers for each line\n"
 493                "-l, --highlight:       Attempts to highlight keywords\n"
 494                "-p, --pager=PAGER:     Sets pager to use (default $PAGER)\n"
 495                "\n"
 496                "Prefix long options with `no-' to cancel them.  Use `+' to "
 497                "cancel short options.\n"
 498                "Options can also be placed in the `BASCAT' environment "
 499                "variable, if you don't\n"
 500                "like the standard settings.\n",
 501                optprog);
 502         exit(0);
 503         break;
 504       case 'n':
 505         bc__flags |= f_linenumbers;
 506         break;
 507       case 'n' | gFlag_negated:
 508         bc__flags &= ~f_linenumbers;
 509         break;
 510       case 'l':
 511         bc__flags |= f_highlight;
 512         break;
 513       case 'l' | gFlag_negated:
 514         bc__flags &= ~f_highlight;
 515         break;
 516       case 'p':
 517         bc__pager = optarg;
 518         break;
 519     }
 520   }
 521 }
 522
 523 /* --- @main@ --- *
 524  *
 525  * Arguments:   @int argc@ = number of arguments
 526  *              @char *argc[]@ = pointer to what the arguments are
 527  *
 528  * Returns:     0 if it all worked
 529  *
 530  * Use:         Displays BASIC programs.
 531  */
 532
 533 int main(int argc, char *argv[])
 534 {
 535   static struct option opts[] = {
 536     { "help", 0, 0, 'h' },
 537     { "version", 0, 0, 'v' },
 538     { "line-numbers", gFlag_negate, 0, 'n' },
 539     { "highlight", gFlag_negate, 0, 'l' },
 540     { "pager", gFlag_argReq, 0, 'p' },
 541     { 0, 0, 0, 0 }
 542   };
 543   static char *shortopts = "hvn+l+p:";
 544
 545   /* --- Parse the command line options --- */
 546
 547   bc__options(argc, argv, shortopts, opts);
 548
 549   /* --- Now do the job --- */
 550
 551   if (optind == argc && isatty(0)) {
 552     fprintf(stderr,
 553             "%s: No filenames given, and standard input is a tty\n"
 554             "To force reading from stdin, use `%s -'.  For help, type "
 555             "`%s --help'.\n",
 556             optprog, optprog, optprog);
 557     exit(0);
 558   }
 559
 560 #ifdef HAVE_LIBTERMCAP
 561   if (bc__flags & f_highlight)
 562     tgetent(bc__termcap, getenv("TERM"));
 563 #endif
 564
 565   {
 566     FILE *in;
 567     FILE *out;
 568
 569     /* --- If output is to a terminal, try paging --- *
 570      *
 571      * All programs which spew text should do this ;-)
 572      */
 573
 574     if (isatty(1)) {
 575       if (!bc__pager)
 576         bc__pager = getenv("PAGER");
 577       if (!bc__pager)
 578         bc__pager = PAGER;              /* Worth a try */
 579       if (strstr(bc__pager, "less"))
 580         bc__flags |= f_less;            /* HACK!!! */
 581       out = popen(bc__pager, "w");
 582       if (!out)
 583         out = stdout;
 584       else {
 585         bc__flags |= f_tty;
 586         signal(SIGPIPE, bc__sigPipe);
 587       }
 588     } else
 589       out = stdout;
 590
 591     /* --- Now go through all the files --- */
 592
 593     if (optind == argc)
 594       bc__file(stdin, out);
 595     else
 596       while (optind < argc) {
 597         if (strcmp(argv[optind], "-") == 0)
 598           bc__file(stdin, out);
 599         else {
 600           in = fopen(argv[optind], "rb");
 601           if (!in) {
 602             fprintf(stderr,
 603                     "%s: Couldn't open input file: %s\n",
 604                     optprog, strerror(errno));
 605           } else {
 606             bc__file(in, out);
 607             fclose(in);
 608           }
 609         }
 610         optind++;
 611       }
 612     if (bc__flags & f_tty)
 613       pclose(out);
 614   }
 615
 616   return (0);
 617 }
 618
 619 /*----- That's all, folks -------------------------------------------------*/