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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: anag.c,v 1.3 2001/02/16 21:45:19 mdw Exp $ |
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4 | * |
5 | * Main driver for anag |
6 | * |
7 | * (c) 2001 Mark Wooding |
8 | */ |
9 | |
10 | /*----- Licensing notice --------------------------------------------------* |
11 | * |
12 | * This file is part of Anag: a simple wordgame helper. |
13 | * |
14 | * Anag is free software; you can redistribute it and/or modify |
15 | * it under the terms of the GNU General Public License as published by |
16 | * the Free Software Foundation; either version 2 of the License, or |
17 | * (at your option) any later version. |
18 | * |
19 | * Anag is distributed in the hope that it will be useful, |
20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
22 | * GNU General Public License for more details. |
23 | * |
24 | * You should have received a copy of the GNU General Public License |
25 | * along with Anag; 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: anag.c,v $ |
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32 | * Revision 1.3 2001/02/16 21:45:19 mdw |
33 | * Be more helpful. Improve full help message. Special-case error for |
34 | * empty command strings. |
35 | * |
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36 | * Revision 1.2 2001/02/07 09:09:11 mdw |
37 | * Fix spurious error when `-file' is used. |
38 | * |
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39 | * Revision 1.1 2001/02/04 17:14:42 mdw |
40 | * Initial checkin |
41 | * |
42 | */ |
43 | |
44 | /*----- Header files ------------------------------------------------------*/ |
45 | |
46 | #include "anag.h" |
47 | |
48 | /*----- Static variables --------------------------------------------------*/ |
49 | |
50 | static const char *file = DICTIONARY; |
51 | |
52 | /*----- Help text functions -----------------------------------------------*/ |
53 | |
54 | static void usage(FILE *fp) |
55 | { |
56 | pquis(fp, "Usage: $ [-f file] expression\n"); |
57 | } |
58 | |
59 | static void version(FILE *fp) |
60 | { |
61 | pquis(fp, "$, version " VERSION "\n"); |
62 | } |
63 | |
64 | static void help(FILE *fp) |
65 | { |
66 | version(fp); |
67 | fputc('\n', fp); |
68 | usage(fp); |
69 | fputs("\n\ |
70 | Searches a wordlist, printing all of the words which match an expression.\n\ |
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71 | \n\ |
72 | Options supported are:\n\ |
73 | \n\ |
74 | -h, --help display this help text\n\ |
75 | -v, --version display the program's version number\n\ |
76 | -u, --usage display a very brief usage message\n\ |
77 | -f, --file FILE read wordlist from FILE, not `" DICTIONARY "'\n\ |
78 | \n\ |
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79 | The basic tests in the expression are:\n\ |
80 | \n\ |
81 | -anagram WORD matches a full-length anagram\n\ |
82 | -subgram WORD matches words which only use letters in WORD\n\ |
83 | -wildcard PATTERN matches with wildcards `*' and `?'\n\ |
84 | -trackword WORD matches words which can be found in a trackword\n\ |
85 | \n\ |
86 | These simple tests can be combined using the operators `-a', `-o' and `-n'\n\ |
87 | (for `and', `or' and `not'; they may also be written `&', `|' and `!' if\n\ |
88 | you like), and grouped using parentheses `(' and `)'.\n\ |
89 | ", fp); |
90 | } |
91 | |
92 | /*----- The options parser ------------------------------------------------*/ |
93 | |
94 | /* --- Options table structure --- */ |
95 | |
96 | struct opt { |
97 | const char *name; |
98 | unsigned nargs; |
99 | unsigned f; |
100 | unsigned tag; |
101 | }; |
102 | |
103 | enum { |
104 | O_HELP, O_VERSION, O_USAGE, |
105 | O_FILE, |
106 | O_AND, O_OR, O_NOT, O_LPAREN, O_RPAREN, |
107 | O_ANAG, O_SUBG, O_WILD, O_TRACK, |
108 | O_EOF |
109 | }; |
110 | |
111 | #define OF_SHORT 1u |
112 | |
113 | static const struct opt opttab[] = { |
114 | |
115 | /* --- Options -- don't form part of the language --- */ |
116 | |
117 | { "help", 0, OF_SHORT, O_HELP }, |
118 | { "version", 0, OF_SHORT, O_VERSION }, |
119 | { "usage", 0, OF_SHORT, O_USAGE }, |
120 | { "file", 1, OF_SHORT, O_FILE }, |
121 | |
122 | /* --- Operators -- provide the basic structure of the language --- * |
123 | * |
124 | * These are also given magical names by the parser. |
125 | */ |
126 | |
127 | { "and", 0, OF_SHORT, O_AND }, |
128 | { "or", 0, OF_SHORT, O_OR }, |
129 | { "not", 0, OF_SHORT, O_NOT }, |
130 | |
131 | /* --- Actual matching oeprations -- do something useful --- */ |
132 | |
133 | { "anagram", 1, 0, O_ANAG }, |
134 | { "subgram", 1, 0, O_SUBG }, |
135 | { "wildcard", 1, 0, O_WILD }, |
136 | { "trackword", 1, 0, O_TRACK }, |
137 | |
138 | /* --- End marker --- */ |
139 | |
140 | { 0, 0, 0, 0 } |
141 | }; |
142 | |
143 | static int ac; |
144 | static const char *const *av; |
145 | static int ai; |
146 | |
147 | /* --- @nextopt@ --- * |
148 | * |
149 | * Arguments: @const char ***arg@ = where to store the arg pointer |
150 | * |
151 | * Returns: The tag of the next option. |
152 | * |
153 | * Use: Scans the next option off the command line. If the option |
154 | * doesn't form part of the language, it's processed internally, |
155 | * and you'll never see it from here. On exit, the @arg@ |
156 | * pointer is set to contain the address of the option scanned, |
157 | * followed by its arguments if any. You're expected to know |
158 | * how many arguments there are for your option. |
159 | */ |
160 | |
161 | static unsigned nextopt(const char *const **arg) |
162 | { |
163 | for (;;) { |
164 | const struct opt *o, *oo; |
165 | size_t sz; |
166 | const char *p; |
167 | |
168 | /* --- Pick the next option off the front --- */ |
169 | |
170 | *arg = av + ai; |
171 | if (ai >= ac) |
172 | return (O_EOF); |
173 | p = av[ai++]; |
174 | |
175 | /* --- Cope with various forms of magic --- */ |
176 | |
177 | if (p[0] != '-') { |
178 | if (!p[1]) switch (*p) { |
179 | case '&': return (O_AND); |
180 | case '|': return (O_OR); |
181 | case '!': return (O_NOT); |
182 | case '(': return (O_LPAREN); |
183 | case ')': return (O_RPAREN); |
184 | } |
185 | goto bad; |
186 | } |
187 | |
188 | /* --- Now cope with other sorts of weirdies --- * |
189 | * |
190 | * By the end of this, a leading `-' or `--' will have been stripped. |
191 | */ |
192 | |
193 | p++; |
194 | if (!*p) |
195 | goto bad; |
196 | if (*p == '-') |
197 | p++; |
198 | if (!*p) { |
199 | if (ai < ac) |
200 | die("syntax error near `--': rubbish at end of line"); |
201 | return (O_EOF); |
202 | } |
203 | |
204 | /* --- Now look the word up in my table --- */ |
205 | |
206 | sz = strlen(p); |
207 | oo = 0; |
208 | for (o = opttab; o->name; o++) { |
209 | if (strncmp(p, o->name, sz) == 0) { |
210 | if (strlen(o->name) == sz || ((o->f & OF_SHORT) && sz == 1)) { |
211 | oo = o; |
212 | break; |
213 | } |
214 | if (oo) { |
215 | die("ambiguous option name `-%s' (could match `-%s' or `-%s')", |
216 | p, oo->name, o->name); |
217 | } |
218 | oo = o; |
219 | } |
220 | } |
221 | if (!oo) |
222 | die("unrecognized option name `-%s'", p); |
223 | |
224 | /* --- Sort out the arguments --- */ |
225 | |
226 | if (ai + oo->nargs > ac) |
227 | die("too few arguments for `-%s' (need %u)", oo->name, oo->nargs); |
228 | ai += oo->nargs; |
229 | |
230 | /* --- Now process the option --- */ |
231 | |
232 | switch (oo->tag) { |
233 | case O_HELP: |
234 | help(stdout); |
235 | exit(0); |
236 | case O_VERSION: |
237 | version(stdout); |
238 | exit(0); |
239 | case O_USAGE: |
240 | usage(stdout); |
241 | exit(0); |
242 | case O_FILE: |
243 | file = (*arg)[1]; |
244 | break; |
245 | default: |
246 | return (oo->tag); |
247 | } |
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248 | continue; |
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249 | bad: |
250 | die("syntax error near `%s': unknown token type", av[ai - 1]); |
251 | } |
252 | } |
253 | |
254 | /*----- Node types for operators ------------------------------------------*/ |
255 | |
256 | /* --- Node structures --- */ |
257 | |
258 | typedef struct node_bin { |
259 | node n; |
260 | node *left; |
261 | node *right; |
262 | } node_bin; |
263 | |
264 | typedef struct node_un { |
265 | node n; |
266 | node *arg; |
267 | } node_un; |
268 | |
269 | /* --- Node functions --- */ |
270 | |
271 | static int n_or(node *nn, const char *p, size_t sz) |
272 | { |
273 | node_bin *n = (node_bin *)nn; |
274 | return (n->left->func(n->left, p, sz) || n->right->func(n->right, p, sz)); |
275 | } |
276 | |
277 | static int n_and(node *nn, const char *p, size_t sz) |
278 | { |
279 | node_bin *n = (node_bin *)nn; |
280 | return (n->left->func(n->left, p, sz) && n->right->func(n->right, p, sz)); |
281 | } |
282 | |
283 | static int n_not(node *nn, const char *p, size_t sz) |
284 | { |
285 | node_un *n = (node_un *)nn; |
286 | return (!n->arg->func(n->arg, p, sz)); |
287 | } |
288 | |
289 | /*----- Parser for the expression syntax ----------------------------------*/ |
290 | |
291 | /* --- A parser context --- */ |
292 | |
293 | typedef struct p_ctx { |
294 | unsigned t; |
295 | const char *const *a; |
296 | } p_ctx; |
297 | |
298 | /* --- Parser structure --- * |
299 | * |
300 | * This is a simple recursive descent parser. The context retains |
301 | * information about the current token. Each function is passed the address |
302 | * of a node pointer to fill in. This simplifies the binary operator code |
303 | * somewhat, relative to returning pointers to node trees. |
304 | */ |
305 | |
306 | static void p_expr(p_ctx *p, node **/*nn*/); |
307 | |
308 | static void p_next(p_ctx *p) |
309 | { |
310 | static const char *const eof[] = { "<end>", 0 }; |
311 | p->t = nextopt(&p->a); |
312 | if (p->t == O_EOF) |
313 | p->a = eof; |
314 | } |
315 | |
316 | static void p_factor(p_ctx *p, node **nn) |
317 | { |
318 | node_un *n; |
319 | if (p->t == O_LPAREN) { |
320 | p_next(p); |
321 | p_expr(p, nn); |
322 | if (p->t != O_RPAREN) |
323 | die("syntax error near `%s': missing `('", *p->a); |
324 | p_next(p); |
325 | } else if (p->t == O_NOT) { |
326 | n = xmalloc(sizeof(node_un)); |
327 | n->n.func = n_not; |
328 | *nn = &n->n; |
329 | p_next(p); |
330 | p_factor(p, &n->arg); |
331 | } else { |
332 | switch (p->t) { |
333 | case O_ANAG: *nn = anagram(p->a + 1); break; |
334 | case O_SUBG: *nn = subgram(p->a + 1); break; |
335 | case O_WILD: *nn = wildcard(p->a + 1); break; |
336 | case O_TRACK: *nn = trackword(p->a + 1); break; |
337 | default: die("syntax error near `%s': unexpected token", *p->a); |
338 | } |
339 | p_next(p); |
340 | } |
341 | } |
342 | |
343 | static void p_term(p_ctx *p, node **nn) |
344 | { |
345 | node_bin *n; |
346 | for (;;) { |
347 | p_factor(p, nn); |
348 | switch (p->t) { |
349 | case O_AND: |
350 | p_next(p); |
351 | default: |
352 | break; |
353 | case O_LPAREN: |
354 | case O_RPAREN: |
355 | case O_OR: |
356 | case O_EOF: |
357 | return; |
358 | } |
359 | n = xmalloc(sizeof(node_bin)); |
360 | n->left = *nn; |
361 | n->n.func = n_and; |
362 | *nn = &n->n; |
363 | nn = &n->right; |
364 | } |
365 | } |
366 | |
367 | static void p_expr(p_ctx *p, node **nn) |
368 | { |
369 | node_bin *n; |
370 | for (;;) { |
371 | p_term(p, nn); |
372 | if (p->t != O_OR) |
373 | break; |
374 | p_next(p); |
375 | n = xmalloc(sizeof(node_bin)); |
376 | n->left = *nn; |
377 | n->n.func = n_or; |
378 | *nn = &n->n; |
379 | nn = &n->right; |
380 | } |
381 | } |
382 | |
383 | /* --- @p_argv@ --- * |
384 | * |
385 | * Arguments: @int argc@ = number of command-line arguments |
386 | * @const char *const argv[]@ = vectoor of arguments |
387 | * |
388 | * Returns: A compiled node, parsed from the arguments. |
389 | * |
390 | * Use: Does the donkey-work of parsing a command-line. |
391 | */ |
392 | |
393 | static node *p_argv(int argc, const char *const argv[]) |
394 | { |
395 | p_ctx p; |
396 | node *n; |
397 | |
398 | av = argv; |
399 | ac = argc; |
400 | ai = 1; |
401 | p_next(&p); |
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402 | if (p.t == O_EOF) { |
403 | usage(stderr); |
404 | pquis(stderr, "(Run `$ --help' for more detail.)\n"); |
405 | exit(EXIT_FAILURE); |
406 | } |
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407 | p_expr(&p, &n); |
408 | if (p.t != O_EOF) { |
409 | die("syntax error near `%s': rubbish at end of line (too many `)'s?)", |
410 | *p.a); |
411 | } |
412 | return (n); |
413 | } |
414 | |
415 | /*----- Main code ---------------------------------------------------------*/ |
416 | |
417 | /* --- @main@ --- * |
418 | * |
419 | * Arguments: @int argc@ = number of command-line arguments |
420 | * @char *argv[]@ = vector of argument words |
421 | * |
422 | * Returns: Zero on success, nonzero on failure. |
423 | * |
424 | * Use: Picks entries from a word list which match particular |
425 | * expressions. This might be of assistance to word-game types. |
426 | */ |
427 | |
428 | int main(int argc, char *argv[]) |
429 | { |
430 | node *n; |
431 | FILE *fp; |
432 | dstr d = DSTR_INIT; |
433 | char *p, *q, *l; |
434 | |
435 | ego(argv[0]); |
436 | n = p_argv(argc, (const char *const *)argv); |
437 | |
438 | if ((fp = fopen(file, "r")) == 0) |
439 | die("error opening `%s': %s", file, strerror(errno)); |
440 | for (;;) { |
441 | dstr_reset(&d); |
442 | if (dstr_putline(&d, fp) < 0) |
443 | break; |
444 | l = d.buf + d.len; |
445 | for (p = q = d.buf; p < l; p++) { |
446 | if (!isalnum((unsigned char)*p)) |
447 | continue; |
448 | *q++ = tolower((unsigned char)*p); |
449 | } |
450 | *q = 0; |
451 | d.len = q - d.buf; |
452 | if (n->func(n, d.buf, d.len)) { |
453 | fwrite(d.buf, 1, d.len, stdout); |
454 | fputc('\n', stdout); |
455 | } |
456 | } |
457 | if (!feof(fp)) |
458 | die("error reading `%s': %s", file, strerror(errno)); |
459 | fclose(fp); |
460 | return (0); |
461 | } |
462 | |
463 | /*----- That's all, folks -------------------------------------------------*/ |