doc/edit-sgml.c

   1 /*
   2  * $Id$
   3  *
   4  * Copyright © 2003 Keith Packard
   5  *
   6  * Permission to use, copy, modify, distribute, and sell this software and its
   7  * documentation for any purpose is hereby granted without fee, provided that
   8  * the above copyright notice appear in all copies and that both that
   9  * copyright notice and this permission notice appear in supporting
  10  * documentation, and that the name of Keith Packard not be used in
  11  * advertising or publicity pertaining to distribution of the software without
  12  * specific, written prior permission.  Keith Packard makes no
  13  * representations about the suitability of this software for any purpose.  It
  14  * is provided "as is" without express or implied warranty.
  15  *
  16  * KEITH PACKARD DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
  17  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
  18  * EVENT SHALL KEITH PACKARD BE LIABLE FOR ANY SPECIAL, INDIRECT OR
  19  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
  20  * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
  21  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
  22  * PERFORMANCE OF THIS SOFTWARE.
  23  */
  24
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28 #include <ctype.h>
  29
  30 static void *
  31 New (int size);
  32
  33 static void *
  34 Reallocate (void *p, int size);
  35
  36 static void
  37 Dispose (void *p);
  38
  39 typedef enum { False, True } Bool;
  40
  41 typedef struct {
  42     char    *buf;
  43     int     size;
  44     int     len;
  45 } String;
  46
  47 static String *
  48 StringNew (void);
  49
  50 static void
  51 StringAdd (String *s, char c);
  52
  53 static void
  54 StringAddString (String *s, char *buf);
  55
  56 static String *
  57 StringMake (char *buf);
  58
  59 static void
  60 StringDel (String *s);
  61
  62 static void
  63 StringPut (FILE *f, String *s);
  64
  65 static void
  66 StringDispose (String *s);
  67
  68 typedef struct {
  69     String  *tag;
  70     String  *text;
  71 } Replace;
  72
  73 static Replace *
  74 ReplaceNew (void);
  75
  76 static void
  77 ReplaceDispose (Replace *r);
  78
  79 static void
  80 Bail (const char *format, const char *arg);
  81
  82 static Replace *
  83 ReplaceRead (FILE *f);
  84
  85 typedef struct _replaceList {
  86     struct _replaceList *next;
  87     Replace             *r;
  88 } ReplaceList;
  89
  90 static ReplaceList *
  91 ReplaceListNew (Replace *r, ReplaceList *next);
  92
  93 static void
  94 ReplaceListDispose (ReplaceList *l);
  95
  96 typedef struct {
  97     ReplaceList *head;
  98 } ReplaceSet;
  99
 100 static ReplaceSet *
 101 ReplaceSetNew (void);
 102
 103 static void
 104 ReplaceSetDispose (ReplaceSet *s);
 105
 106 static void
 107 ReplaceSetAdd (ReplaceSet *s, Replace *r);
 108
 109 static Replace *
 110 ReplaceSetFind (ReplaceSet *s, char *tag);
 111
 112 static ReplaceSet *
 113 ReplaceSetRead (FILE *f);
 114
 115 typedef struct _skipStack {
 116     struct _skipStack   *prev;
 117     int                 skipping;
 118 } SkipStack;
 119
 120 static SkipStack *
 121 SkipStackPush (SkipStack *prev, int skipping);
 122
 123 static SkipStack *
 124 SkipStackPop (SkipStack *prev);
 125
 126 typedef struct _loopStack {
 127     struct _loopStack   *prev;
 128     String              *tag;
 129     String              *extra;
 130     long                pos;
 131 } LoopStack;
 132
 133 static LoopStack *
 134 LoopStackPush (LoopStack *prev, FILE *f, char *tag);
 135
 136 static LoopStack *
 137 LoopStackLoop (ReplaceSet *rs, LoopStack *ls, FILE *f);
 138
 139 static void
 140 LineSkip (FILE *f);
 141
 142 static void
 143 DoReplace (FILE *f, ReplaceSet *s);
 144
 145 #define STRING_INIT 128
 146
 147 static void *
 148 New (int size)
 149 {
 150     void    *m = malloc (size);
 151     if (!m)
 152         abort ();
 153     return m;
 154 }
 155
 156 static void *
 157 Reallocate (void *p, int size)
 158 {
 159     void    *r = realloc (p, size);
 160
 161     if (!r)
 162         abort ();
 163     return r;
 164 }
 165
 166 static void
 167 Dispose (void *p)
 168 {
 169     free (p);
 170 }
 171
 172 static String *
 173 StringNew (void)
 174 {
 175     String  *s;
 176
 177     s = New (sizeof (String));
 178     s->buf = New (STRING_INIT);
 179     s->size = STRING_INIT - 1;
 180     s->buf[0] = '\0';
 181     s->len = 0;
 182     return s;
 183 }
 184
 185 static void
 186 StringAdd (String *s, char c)
 187 {
 188     if (s->len == s->size)
 189         s->buf = Reallocate (s->buf, (s->size *= 2) + 1);
 190     s->buf[s->len++] = c;
 191     s->buf[s->len] = '\0';
 192 }
 193
 194 static void
 195 StringAddString (String *s, char *buf)
 196 {
 197     while (*buf)
 198         StringAdd (s, *buf++);
 199 }
 200
 201 static String *
 202 StringMake (char *buf)
 203 {
 204     String  *s = StringNew ();
 205     StringAddString (s, buf);
 206     return s;
 207 }
 208
 209 static void
 210 StringDel (String *s)
 211 {
 212     if (s->len)
 213         s->buf[--s->len] = '\0';
 214 }
 215
 216 static void
 217 StringPut (FILE *f, String *s)
 218 {
 219     char    *b = s->buf;
 220
 221     while (*b)
 222         putc (*b++, f);
 223 }
 224
 225 #define StringLast(s)   ((s)->len ? (s)->buf[(s)->len - 1] : '\0')
 226
 227 static void
 228 StringDispose (String *s)
 229 {
 230     Dispose (s->buf);
 231     Dispose (s);
 232 }
 233
 234 static Replace *
 235 ReplaceNew (void)
 236 {
 237     Replace *r = New (sizeof (Replace));
 238     r->tag = StringNew ();
 239     r->text = StringNew ();
 240     return r;
 241 }
 242
 243 static void
 244 ReplaceDispose (Replace *r)
 245 {
 246     StringDispose (r->tag);
 247     StringDispose (r->text);
 248     Dispose (r);
 249 }
 250
 251 static void
 252 Bail (const char *format, const char *arg)
 253 {
 254     fprintf (stderr, "fatal: ");
 255     fprintf (stderr, format, arg);
 256     fprintf (stderr, "\n");
 257     exit (1);
 258 }
 259
 260 static Replace *
 261 ReplaceRead (FILE *f)
 262 {
 263     int     c;
 264     Replace *r;
 265
 266     while ((c = getc (f)) != '@')
 267     {
 268         if (c == EOF)
 269             return 0;
 270     }
 271     r = ReplaceNew();
 272     while ((c = getc (f)) != '@')
 273     {
 274         if (c == EOF)
 275         {
 276             ReplaceDispose (r);
 277             return 0;
 278         }
 279         if (isspace (c))
 280             Bail ("invalid character after tag %s", r->tag->buf);
 281         StringAdd (r->tag, c);
 282     }
 283     if (r->tag->buf[0] == '\0')
 284     {
 285         ReplaceDispose (r);
 286         return 0;
 287     }
 288     while (isspace ((c = getc (f))))
 289         ;
 290     ungetc (c, f);
 291     while ((c = getc (f)) != '@' && c != EOF)
 292         StringAdd (r->text, c);
 293     if (c == '@')
 294         ungetc (c, f);
 295     while (isspace (StringLast (r->text)))
 296         StringDel (r->text);
 297     return r;
 298 }
 299
 300 static ReplaceList *
 301 ReplaceListNew (Replace *r, ReplaceList *next)
 302 {
 303     ReplaceList *l = New (sizeof (ReplaceList));
 304     l->r = r;
 305     l->next = next;
 306     return l;
 307 }
 308
 309 static void
 310 ReplaceListDispose (ReplaceList *l)
 311 {
 312     if (l)
 313     {
 314         ReplaceListDispose (l->next);
 315         ReplaceDispose (l->r);
 316         Dispose (l);
 317     }
 318 }
 319
 320 static ReplaceSet *
 321 ReplaceSetNew (void)
 322 {
 323     ReplaceSet  *s = New (sizeof (ReplaceSet));
 324     s->head = 0;
 325     return s;
 326 }
 327
 328 static void
 329 ReplaceSetDispose (ReplaceSet *s)
 330 {
 331     ReplaceListDispose (s->head);
 332     Dispose (s);
 333 }
 334
 335 static void
 336 ReplaceSetAdd (ReplaceSet *s, Replace *r)
 337 {
 338     s->head = ReplaceListNew (r, s->head);
 339 }
 340
 341 static Replace *
 342 ReplaceSetFind (ReplaceSet *s, char *tag)
 343 {
 344     ReplaceList *l;
 345
 346     for (l = s->head; l; l = l->next)
 347         if (!strcmp (tag, l->r->tag->buf))
 348             return l->r;
 349     return 0;
 350 }
 351
 352 static ReplaceSet *
 353 ReplaceSetRead (FILE *f)
 354 {
 355     ReplaceSet  *s = ReplaceSetNew ();
 356     Replace     *r;
 357
 358     while ((r = ReplaceRead (f)))
 359     {
 360         while (ReplaceSetFind (s, r->tag->buf))
 361             StringAdd (r->tag, '+');
 362         ReplaceSetAdd (s, r);
 363     }
 364     if (!s->head)
 365     {
 366         ReplaceSetDispose (s);
 367         s = 0;
 368     }
 369     return s;
 370 }
 371
 372 static SkipStack *
 373 SkipStackPush (SkipStack *prev, int skipping)
 374 {
 375     SkipStack   *ss = New (sizeof (SkipStack));
 376     ss->prev = prev;
 377     ss->skipping = skipping;
 378     return ss;
 379 }
 380
 381 static SkipStack *
 382 SkipStackPop (SkipStack *prev)
 383 {
 384     SkipStack   *ss = prev->prev;
 385     Dispose (prev);
 386     return ss;
 387 }
 388
 389 static LoopStack *
 390 LoopStackPush (LoopStack *prev, FILE *f, char *tag)
 391 {
 392     LoopStack   *ls = New (sizeof (LoopStack));
 393     ls->prev = prev;
 394     ls->tag = StringMake (tag);
 395     ls->extra = StringNew ();
 396     ls->pos = ftell (f);
 397     return ls;
 398 }
 399
 400 static LoopStack *
 401 LoopStackLoop (ReplaceSet *rs, LoopStack *ls, FILE *f)
 402 {
 403     String      *s = StringMake (ls->tag->buf);
 404     LoopStack   *ret = ls;
 405     Bool        loop;
 406
 407     StringAdd (ls->extra, '+');
 408     StringAddString (s, ls->extra->buf);
 409     loop = ReplaceSetFind (rs, s->buf) != 0;
 410     StringDispose (s);
 411     if (loop)
 412         fseek (f, ls->pos, SEEK_SET);
 413     else
 414     {
 415         ret = ls->prev;
 416         StringDispose (ls->tag);
 417         StringDispose (ls->extra);
 418         Dispose (ls);
 419     }
 420     return ret;
 421 }
 422
 423 static void
 424 LineSkip (FILE *f)
 425 {
 426     int c;
 427
 428     while ((c = getc (f)) == '\n')
 429         ;
 430     ungetc (c, f);
 431 }
 432
 433 static void
 434 DoReplace (FILE *f, ReplaceSet *s)
 435 {
 436     int         c;
 437     String      *tag;
 438     Replace     *r;
 439     SkipStack   *ss = 0;
 440     LoopStack   *ls = 0;
 441     int         skipping = 0;
 442
 443     while ((c = getc (f)) != EOF)
 444     {
 445         if (c == '@')
 446         {
 447             tag = StringNew ();
 448             while ((c = getc (f)) != '@')
 449             {
 450                 if (c == EOF)
 451                     abort ();
 452                 StringAdd (tag, c);
 453             }
 454             if (ls)
 455                 StringAddString (tag, ls->extra->buf);
 456             switch (tag->buf[0]) {
 457             case '?':
 458                 ss = SkipStackPush (ss, skipping);
 459                 if (!ReplaceSetFind (s, tag->buf + 1))
 460                     skipping++;
 461                 LineSkip (f);
 462                 break;
 463             case ':':
 464                 if (!ss)
 465                     abort ();
 466                 if (ss->skipping == skipping)
 467                     ++skipping;
 468                 else
 469                     --skipping;
 470                 LineSkip (f);
 471                 break;
 472             case ';':
 473                 skipping = ss->skipping;
 474                 ss = SkipStackPop (ss);
 475                 LineSkip (f);
 476                 break;
 477             case '{':
 478                 ls = LoopStackPush (ls, f, tag->buf + 1);
 479                 LineSkip (f);
 480                 break;
 481             case '}':
 482                 ls = LoopStackLoop (s, ls, f);
 483                 LineSkip (f);
 484                 break;
 485             default:
 486                 r = ReplaceSetFind (s, tag->buf);
 487                 if (r && !skipping)
 488                     StringPut (stdout, r->text);
 489                 break;
 490             }
 491             StringDispose (tag);
 492         }
 493         else if (!skipping)
 494             putchar (c);
 495     }
 496 }
 497
 498 int
 499 main (int argc, char **argv)
 500 {
 501     FILE        *f;
 502     ReplaceSet  *s;
 503
 504     if (!argv[1])
 505         Bail ("usage: %s <template.sgml>", argv[0]);
 506     f = fopen (argv[1], "r");
 507     if (!f)
 508     {
 509         Bail ("can't open file %s", argv[1]);
 510         exit (1);
 511     }
 512     while ((s = ReplaceSetRead (stdin)))
 513     {
 514         DoReplace (f, s);
 515         ReplaceSetDispose (s);
 516         rewind (f);
 517     }
 518     if (ferror (stdout))
 519         Bail ("%s", "error writing output");
 520     exit (0);
 521 }