1 /* $NetBSD: quiz.c,v 1.29 2023/01/22 17:19:11 rillig Exp $ */
2
3 /*-
4 * Copyright (c) 1991, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Jim R. Oldroyd at The Instruction Set and Keith Gabryelski at
9 * Commodore Business Machines.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 * may be used to endorse or promote products derived from this software
21 * without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36 #include <sys/cdefs.h>
37 #ifndef lint
38 __COPYRIGHT("@(#) Copyright (c) 1991, 1993\
39 The Regents of the University of California. All rights reserved.");
40 #endif /* not lint */
41
42 #ifndef lint
43 #if 0
44 static char sccsid[] = "@(#)quiz.c 8.3 (Berkeley) 5/4/95";
45 #else
46 __RCSID("$NetBSD: quiz.c,v 1.29 2023/01/22 17:19:11 rillig Exp $");
47 #endif
48 #endif /* not lint */
49
50 #include <sys/types.h>
51
52 #include <ctype.h>
53 #include <errno.h>
54 #include <stdio.h>
55 #include <stdlib.h>
56 #include <string.h>
57 #include <err.h>
58 #include <time.h>
59 #include <unistd.h>
60 #include "quiz.h"
61 #include "pathnames.h"
62
63 static QE qlist;
64 static int catone, cattwo, tflag;
65 static unsigned qsize;
66
67 static char *appdstr(char *, const char *, size_t);
68 static void downcase(char *);
69 static void get_cats(char *, char *);
70 static void get_file(const char *);
71 static const char *next_cat(const char *);
72 static void quiz(void);
73 static void score(unsigned, unsigned, unsigned);
74 static void show_index(void);
75 static void usage(void) __dead;
76
77 int
main(int argc,char * argv[])78 main(int argc, char *argv[])
79 {
80 int ch;
81 const char *indexfile;
82
83 /* Revoke setgid privileges */
84 setgid(getgid());
85
86 indexfile = _PATH_QUIZIDX;
87 while ((ch = getopt(argc, argv, "i:t")) != -1)
88 switch(ch) {
89 case 'i':
90 indexfile = optarg;
91 break;
92 case 't':
93 tflag = 1;
94 break;
95 case '?':
96 default:
97 usage();
98 }
99 argc -= optind;
100 argv += optind;
101
102 switch(argc) {
103 case 0:
104 get_file(indexfile);
105 show_index();
106 break;
107 case 2:
108 get_file(indexfile);
109 get_cats(argv[0], argv[1]);
110 quiz();
111 break;
112 default:
113 usage();
114 }
115 exit(0);
116 }
117
118 static void
get_file(const char * file)119 get_file(const char *file)
120 {
121 FILE *fp;
122 QE *qp;
123 size_t len;
124 char *lp;
125
126 if ((fp = fopen(file, "r")) == NULL)
127 err(1, "%s", file);
128
129 /*
130 * XXX
131 * Should really free up space from any earlier read list
132 * but there are no reverse pointers to do so with.
133 */
134 qp = &qlist;
135 qsize = 0;
136 while ((lp = fgetln(fp, &len)) != NULL) {
137 if (lp[len - 1] == '\n')
138 lp[--len] = '\0';
139 if (qp->q_text && qp->q_text[strlen(qp->q_text) - 1] == '\\')
140 qp->q_text = appdstr(qp->q_text, lp, len);
141 else {
142 if ((qp->q_next = malloc(sizeof(QE))) == NULL)
143 errx(1, "malloc");
144 qp = qp->q_next;
145 if ((qp->q_text = malloc(len + 1)) == NULL)
146 errx(1, "malloc");
147 strncpy(qp->q_text, lp, len);
148 qp->q_text[len] = '\0';
149 qp->q_asked = qp->q_answered = FALSE;
150 qp->q_next = NULL;
151 ++qsize;
152 }
153 }
154 (void)fclose(fp);
155 }
156
157 static void
show_index(void)158 show_index(void)
159 {
160 QE *qp;
161 const char *p, *s;
162 FILE *pf;
163 const char *pager;
164
165 if (!isatty(1))
166 pager = "cat";
167 else {
168 if (!(pager = getenv("PAGER")) || (*pager == 0))
169 pager = _PATH_PAGER;
170 }
171 if ((pf = popen(pager, "w")) == NULL)
172 err(1, "%s", pager);
173 (void)fprintf(pf, "Subjects:\n\n");
174 for (qp = qlist.q_next; qp; qp = qp->q_next) {
175 for (s = next_cat(qp->q_text); s; s = next_cat(s)) {
176 if (!rxp_compile(s))
177 errx(1, "%s", rxperr);
178 if ((p = rxp_expand()) != NULL)
179 (void)fprintf(pf, "%s ", p);
180 }
181 (void)fprintf(pf, "\n");
182 }
183 (void)fprintf(pf, "\n%s\n%s\n%s\n",
184 "For example, \"quiz victim killer\" prints a victim's name and you reply",
185 "with the killer, and \"quiz killer victim\" works the other way around.",
186 "Type an empty line to get the correct answer.");
187 (void)pclose(pf);
188 }
189
190 static void
get_cats(char * cat1,char * cat2)191 get_cats(char *cat1, char *cat2)
192 {
193 QE *qp;
194 int i;
195 const char *s;
196
197 downcase(cat1);
198 downcase(cat2);
199 for (qp = qlist.q_next; qp; qp = qp->q_next) {
200 s = next_cat(qp->q_text);
201 catone = cattwo = i = 0;
202 while (s) {
203 if (!rxp_compile(s))
204 errx(1, "%s", rxperr);
205 i++;
206 if (rxp_match(cat1))
207 catone = i;
208 if (rxp_match(cat2))
209 cattwo = i;
210 s = next_cat(s);
211 }
212 if (catone && cattwo && catone != cattwo) {
213 if (!rxp_compile(qp->q_text))
214 errx(1, "%s", rxperr);
215 get_file(rxp_expand());
216 return;
217 }
218 }
219 errx(1, "invalid categories");
220 }
221
222 static void
quiz(void)223 quiz(void)
224 {
225 QE *qp;
226 int i;
227 size_t len;
228 unsigned guesses, rights, wrongs;
229 unsigned next, j;
230 char *answer, *t, question[LINE_SZ];
231 const char *s;
232
233 srandom(time(NULL));
234 guesses = rights = wrongs = 0;
235 for (;;) {
236 if (qsize == 0)
237 break;
238 next = random() % qsize;
239 qp = qlist.q_next;
240 for (j = 0; j < next; j++)
241 qp = qp->q_next;
242 while (qp && qp->q_answered)
243 qp = qp->q_next;
244 if (!qp) {
245 qsize = next;
246 continue;
247 }
248 if (tflag && random() % 100 > 20) {
249 /* repeat questions in tutorial mode */
250 while (qp && (!qp->q_asked || qp->q_answered))
251 qp = qp->q_next;
252 if (!qp)
253 continue;
254 }
255 s = qp->q_text;
256 for (i = 0; i < catone - 1; i++)
257 s = next_cat(s);
258 if (!rxp_compile(s))
259 errx(1, "%s", rxperr);
260 t = rxp_expand();
261 if (!t || *t == '\0') {
262 qp->q_answered = TRUE;
263 continue;
264 }
265 (void)strcpy(question, t);
266 s = qp->q_text;
267 for (i = 0; i < cattwo - 1; i++)
268 s = next_cat(s);
269 if (!rxp_compile(s))
270 errx(1, "%s", rxperr);
271 t = rxp_expand();
272 if (!t || *t == '\0') {
273 qp->q_answered = TRUE;
274 continue;
275 }
276 qp->q_asked = TRUE;
277 (void)printf("%s?\n", question);
278 for (;; ++guesses) {
279 if ((answer = fgetln(stdin, &len)) == NULL ||
280 answer[len - 1] != '\n') {
281 score(rights, wrongs, guesses);
282 exit(0);
283 }
284 answer[len - 1] = '\0';
285 downcase(answer);
286 if (rxp_match(answer)) {
287 (void)printf("Right!\n");
288 ++rights;
289 qp->q_answered = TRUE;
290 break;
291 }
292 if (*answer == '\0') {
293 (void)printf("%s\n", t);
294 ++wrongs;
295 if (!tflag)
296 qp->q_answered = TRUE;
297 break;
298 }
299 (void)printf("What?\n");
300 }
301 }
302 score(rights, wrongs, guesses);
303 }
304
305 static const char *
next_cat(const char * s)306 next_cat(const char *s)
307 {
308 int esc;
309
310 esc = 0;
311 for (;;)
312 switch (*s++) {
313 case '\0':
314 return (NULL);
315 case '\\':
316 esc = 1;
317 break;
318 case ':':
319 if (!esc)
320 return (s);
321 /* FALLTHROUGH */
322 default:
323 esc = 0;
324 break;
325 }
326 /* NOTREACHED */
327 }
328
329 static char *
appdstr(char * s,const char * tp,size_t len)330 appdstr(char *s, const char *tp, size_t len)
331 {
332 char *mp;
333 const char *sp;
334 int ch;
335 char *m;
336
337 if ((m = malloc(strlen(s) + len + 1)) == NULL)
338 errx(1, "malloc");
339 for (mp = m, sp = s; (*mp++ = *sp++) != '\0'; )
340 ;
341 --mp;
342 if (*(mp - 1) == '\\')
343 --mp;
344
345 while ((ch = *mp++ = *tp++) && ch != '\n')
346 ;
347 *mp = '\0';
348
349 free(s);
350 return (m);
351 }
352
353 static void
score(unsigned r,unsigned w,unsigned g)354 score(unsigned r, unsigned w, unsigned g)
355 {
356 (void)printf("Rights %d, wrongs %d,", r, w);
357 if (g)
358 (void)printf(" extra guesses %d,", g);
359 (void)printf(" score %d%%\n", (r + w + g) ? r * 100 / (r + w + g) : 0);
360 }
361
362 static void
downcase(char * p)363 downcase(char *p)
364 {
365 unsigned char ch;
366
367 for (; (ch = *p) != '\0'; ++p)
368 if (isascii(ch) && isupper(ch))
369 *p = tolower(ch);
370 }
371
372 static void
usage(void)373 usage(void)
374 {
375 (void)fprintf(stderr, "quiz [-t] [-i file] category1 category2\n");
376 exit(1);
377 }
378