quiz/quiz.c

   1 /*      $NetBSD: quiz.c,v 1.28 2019/02/03 03:19:25 mrg 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 1.28 2019/02/03 03:19:25 mrg 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         int 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 }