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      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
     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
    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
    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
    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
    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 *
    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 *
    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
    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
    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
    373 usage(void)
    374 {
    375 	(void)fprintf(stderr, "quiz [-t] [-i file] category1 category2\n");
    376 	exit(1);
    377 }
    378