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quiz.c revision 1.19 
      1 /*	$NetBSD: quiz.c,v 1.19 2003/08/07 09:37:34 agc 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\n\
     39 	The Regents of the University of California.  All rights reserved.\n");
     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 1.19 2003/08/07 09:37:34 agc 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 <ctype.h>
     58 #include <err.h>
     59 #include <time.h>
     60 #include <unistd.h>
     61 #include "quiz.h"
     62 #include "pathnames.h"
     63 
     64 static QE qlist;
     65 static int catone, cattwo, tflag;
     66 static u_int qsize;
     67 
     68 char	*appdstr __P((char *, const char *, size_t));
     69 void	 downcase __P((char *));
     70 void	 get_cats __P((char *, char *));
     71 void	 get_file __P((const char *));
     72 int	 main __P((int, char *[]));
     73 const char	*next_cat __P((const char *));
     74 void	 quiz __P((void));
     75 void	 score __P((u_int, u_int, u_int));
     76 void	 show_index __P((void));
     77 void	 usage __P((void)) __attribute__((__noreturn__));
     78 
     79 int
     80 main(argc, argv)
     81 	int argc;
     82 	char *argv[];
     83 {
     84 	int ch;
     85 	const char *indexfile;
     86 
     87 	/* Revoke setgid privileges */
     88 	setgid(getgid());
     89 
     90 	indexfile = _PATH_QUIZIDX;
     91 	while ((ch = getopt(argc, argv, "i:t")) != -1)
     92 		switch(ch) {
     93 		case 'i':
     94 			indexfile = optarg;
     95 			break;
     96 		case 't':
     97 			tflag = 1;
     98 			break;
     99 		case '?':
    100 		default:
    101 			usage();
    102 		}
    103 	argc -= optind;
    104 	argv += optind;
    105 
    106 	switch(argc) {
    107 	case 0:
    108 		get_file(indexfile);
    109 		show_index();
    110 		break;
    111 	case 2:
    112 		get_file(indexfile);
    113 		get_cats(argv[0], argv[1]);
    114 		quiz();
    115 		break;
    116 	default:
    117 		usage();
    118 	}
    119 	exit(0);
    120 }
    121 
    122 void
    123 get_file(file)
    124 	const char *file;
    125 {
    126 	FILE *fp;
    127 	QE *qp;
    128 	size_t len;
    129 	char *lp;
    130 
    131 	if ((fp = fopen(file, "r")) == NULL)
    132 		err(1, "%s", file);
    133 
    134 	/*
    135 	 * XXX
    136 	 * Should really free up space from any earlier read list
    137 	 * but there are no reverse pointers to do so with.
    138 	 */
    139 	qp = &qlist;
    140 	qsize = 0;
    141 	while ((lp = fgetln(fp, &len)) != NULL) {
    142 		if (lp[len - 1] == '\n')
    143 			lp[--len] = '\0';
    144 		if (qp->q_text && qp->q_text[strlen(qp->q_text) - 1] == '\\')
    145 			qp->q_text = appdstr(qp->q_text, lp, len);
    146 		else {
    147 			if ((qp->q_next = malloc(sizeof(QE))) == NULL)
    148 				errx(1, "malloc");
    149 			qp = qp->q_next;
    150 			if ((qp->q_text = malloc(len + 1)) == NULL)
    151 				errx(1, "malloc");
    152 			strncpy(qp->q_text, lp, len);
    153 			qp->q_text[len] = '\0';
    154 			qp->q_asked = qp->q_answered = FALSE;
    155 			qp->q_next = NULL;
    156 			++qsize;
    157 		}
    158 	}
    159 	(void)fclose(fp);
    160 }
    161 
    162 void
    163 show_index()
    164 {
    165 	QE *qp;
    166 	const char *p, *s;
    167 	FILE *pf;
    168 	const char *pager;
    169 
    170 	if (!isatty(1))
    171 		pager = "cat";
    172 	else {
    173 		if (!(pager = getenv("PAGER")) || (*pager == 0))
    174 			pager = _PATH_PAGER;
    175 	}
    176 	if ((pf = popen(pager, "w")) == NULL)
    177 		err(1, "%s", pager);
    178 	(void)fprintf(pf, "Subjects:\n\n");
    179 	for (qp = qlist.q_next; qp; qp = qp->q_next) {
    180 		for (s = next_cat(qp->q_text); s; s = next_cat(s)) {
    181 			if (!rxp_compile(s))
    182 				errx(1, "%s", rxperr);
    183 			if ((p = rxp_expand()) != NULL)
    184 				(void)fprintf(pf, "%s ", p);
    185 		}
    186 		(void)fprintf(pf, "\n");
    187 	}
    188 	(void)fprintf(pf, "\n%s\n%s\n%s\n",
    189 "For example, \"quiz victim killer\" prints a victim's name and you reply",
    190 "with the killer, and \"quiz killer victim\" works the other way around.",
    191 "Type an empty line to get the correct answer.");
    192 	(void)pclose(pf);
    193 }
    194 
    195 void
    196 get_cats(cat1, cat2)
    197 	char *cat1, *cat2;
    198 {
    199 	QE *qp;
    200 	int i;
    201 	const char *s;
    202 
    203 	downcase(cat1);
    204 	downcase(cat2);
    205 	for (qp = qlist.q_next; qp; qp = qp->q_next) {
    206 		s = next_cat(qp->q_text);
    207 		catone = cattwo = i = 0;
    208 		while (s) {
    209 			if (!rxp_compile(s))
    210 				errx(1, "%s", rxperr);
    211 			i++;
    212 			if (rxp_match(cat1))
    213 				catone = i;
    214 			if (rxp_match(cat2))
    215 				cattwo = i;
    216 			s = next_cat(s);
    217 		}
    218 		if (catone && cattwo && catone != cattwo) {
    219 			if (!rxp_compile(qp->q_text))
    220 				errx(1, "%s", rxperr);
    221 			get_file(rxp_expand());
    222 			return;
    223 		}
    224 	}
    225 	errx(1, "invalid categories");
    226 }
    227 
    228 void
    229 quiz()
    230 {
    231 	QE *qp;
    232 	int i;
    233 	size_t len;
    234 	u_int guesses, rights, wrongs;
    235 	int next;
    236 	char *answer, *t, question[LINE_SZ];
    237 	const char *s;
    238 
    239 	srandom(time(NULL));
    240 	guesses = rights = wrongs = 0;
    241 	for (;;) {
    242 		if (qsize == 0)
    243 			break;
    244 		next = random() % qsize;
    245 		qp = qlist.q_next;
    246 		for (i = 0; i < next; i++)
    247 			qp = qp->q_next;
    248 		while (qp && qp->q_answered)
    249 			qp = qp->q_next;
    250 		if (!qp) {
    251 			qsize = next;
    252 			continue;
    253 		}
    254 		if (tflag && random() % 100 > 20) {
    255 			/* repeat questions in tutorial mode */
    256 			while (qp && (!qp->q_asked || qp->q_answered))
    257 				qp = qp->q_next;
    258 			if (!qp)
    259 				continue;
    260 		}
    261 		s = qp->q_text;
    262 		for (i = 0; i < catone - 1; i++)
    263 			s = next_cat(s);
    264 		if (!rxp_compile(s))
    265 			errx(1, "%s", rxperr);
    266 		t = rxp_expand();
    267 		if (!t || *t == '\0') {
    268 			qp->q_answered = TRUE;
    269 			continue;
    270 		}
    271 		(void)strcpy(question, t);
    272 		s = qp->q_text;
    273 		for (i = 0; i < cattwo - 1; i++)
    274 			s = next_cat(s);
    275 		if (!rxp_compile(s))
    276 			errx(1, "%s", rxperr);
    277 		t = rxp_expand();
    278 		if (!t || *t == '\0') {
    279 			qp->q_answered = TRUE;
    280 			continue;
    281 		}
    282 		qp->q_asked = TRUE;
    283 		(void)printf("%s?\n", question);
    284 		for (;; ++guesses) {
    285 			if ((answer = fgetln(stdin, &len)) == NULL ||
    286 			    answer[len - 1] != '\n') {
    287 				score(rights, wrongs, guesses);
    288 				exit(0);
    289 			}
    290 			answer[len - 1] = '\0';
    291 			downcase(answer);
    292 			if (rxp_match(answer)) {
    293 				(void)printf("Right!\n");
    294 				++rights;
    295 				qp->q_answered = TRUE;
    296 				break;
    297 			}
    298 			if (*answer == '\0') {
    299 				(void)printf("%s\n", t);
    300 				++wrongs;
    301 				if (!tflag)
    302 					qp->q_answered = TRUE;
    303 				break;
    304 			}
    305 			(void)printf("What?\n");
    306 		}
    307 	}
    308 	score(rights, wrongs, guesses);
    309 }
    310 
    311 const char *
    312 next_cat(s)
    313 	const char *	s;
    314 {
    315 	int esc;
    316 
    317 	esc = 0;
    318 	for (;;)
    319 		switch (*s++) {
    320 		case '\0':
    321 			return (NULL);
    322 		case '\\':
    323 			esc = 1;
    324 			break;
    325 		case ':':
    326 			if (!esc)
    327 				return (s);
    328 		default:
    329 			esc = 0;
    330 			break;
    331 		}
    332 	/* NOTREACHED */
    333 }
    334 
    335 char *
    336 appdstr(s, tp, len)
    337 	char *s;
    338 	const char *tp;
    339 	size_t len;
    340 {
    341 	char *mp;
    342 	const char *sp;
    343 	int ch;
    344 	char *m;
    345 
    346 	if ((m = malloc(strlen(s) + len + 1)) == NULL)
    347 		errx(1, "malloc");
    348 	for (mp = m, sp = s; (*mp++ = *sp++) != '\0'; )
    349 		;
    350 	--mp;
    351 	if (*(mp - 1) == '\\')
    352 		--mp;
    353 
    354 	while ((ch = *mp++ = *tp++) && ch != '\n')
    355 		;
    356 	*mp = '\0';
    357 
    358 	free(s);
    359 	return (m);
    360 }
    361 
    362 void
    363 score(r, w, g)
    364 	u_int r, w, g;
    365 {
    366 	(void)printf("Rights %d, wrongs %d,", r, w);
    367 	if (g)
    368 		(void)printf(" extra guesses %d,", g);
    369 	(void)printf(" score %d%%\n", (r + w + g) ? r * 100 / (r + w + g) : 0);
    370 }
    371 
    372 void
    373 downcase(p)
    374 	char *p;
    375 {
    376 	int ch;
    377 
    378 	for (; (ch = *p) != '\0'; ++p)
    379 		if (isascii(ch) && isupper(ch))
    380 			*p = tolower(ch);
    381 }
    382 
    383 void
    384 usage()
    385 {
    386 	(void)fprintf(stderr, "quiz [-t] [-i file] category1 category2\n");
    387 	exit(1);
    388 }
    389