FreeBSD/Linux Kernel Cross Reference
sys/ddb/db_hangman.c

     /*      $OpenBSD: db_hangman.c,v 1.38 2020/10/15 03:14:00 deraadt Exp $ */
     
     /*
      * Copyright (c) 1996 Theo de Raadt, Michael Shalayeff
      * All rights reserved.
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
      * are met:
     * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     *
     */
    
    #include <sys/param.h>
    #include <sys/systm.h>
    
    #include <machine/db_machdep.h>
    
    #include <ddb/db_sym.h>
    #include <ddb/db_output.h>
    
    #include <dev/cons.h>
    
    #define ABC_ISCLR(c)    sabc->abc[(c)-'a']==0
    #define ABC_ISWRONG(c)  sabc->abc[(c)-'a']=='_'
    #define ABC_SETWRONG(c)         (sabc->abc[(c)-'a']='_')
    #define ABC_SETRIGHT(c)         (sabc->abc[(c)-'a']='+')
    #define ABC_CLR()       memset(sabc->abc,0,sizeof sabc->abc)
    struct _abc {
            char    abc[26+2];      /* for int32 alignment */
    };
    
    #define TOLOWER(c)      ((c)|0x20)
    #define ISLOWALPHA(c)   ('a'<=(c) && (c)<='z')
    #define ISALPHA(c)      ISLOWALPHA(TOLOWER(c))
    
    void     db_hang(int, char *, struct _abc *);
    
    u_long          db_plays, db_guesses;
    
    static const char hangpic[]=
            "\n88888\r\n"
            "9 7 6\r\n"
            "97  5\r\n"
            "9  423\r\n"
            "9   2\r\n"
            "9  1 0\r\n"
            "9\r\n"
            "9  ";
    static const char substchar[]="\\/|\\/O|/-|";
    
    struct db_hang_forall_arg {
            int cnt;
            Elf_Sym *sym;
    };
    
    /*
     * Horrible abuse of the forall function, but we're not in a hurry.
     */
    static void db_hang_forall(Elf_Sym *, char *, char *, int, void *);
    
    static void
    db_hang_forall(Elf_Sym *sym, char *name, char *suff, int pre, void *varg)
    {
            struct db_hang_forall_arg *arg = varg;
    
            if (arg->cnt-- == 0)
                    arg->sym = sym;
    }
    
    static __inline char *
    db_randomsym(size_t *lenp)
    {
            int nsyms;
            char    *p, *q;
            struct db_hang_forall_arg dfa;
    
            dfa.cnt = 0;
            db_elf_sym_forall(db_hang_forall, &dfa);
            nsyms = -dfa.cnt;
    
            if (nsyms == 0)
                    return (NULL);
    
           dfa.cnt = arc4random_uniform(nsyms);
           db_elf_sym_forall(db_hang_forall, &dfa);
   
           db_symbol_values(dfa.sym, &q, 0);
   
           /* strlen(q) && ignoring underscores and colons */
           for ((*lenp) = 0, p = q; *p; p++)
                   if (ISALPHA(*p))
                           (*lenp)++;
   
           return (q);
   }
   
   void
   db_hang(int tries, char *word, struct _abc *sabc)
   {
           const char      *p;
           int i;
           int c;
   #ifdef ABC_BITMASK
           int m;
   #endif
   
           for (p = hangpic; *p; p++)
                   cnputc((*p >= '' && *p <= '9') ? ((tries <= (*p) - '') ?
                       substchar[(*p) - ''] : ' ') : *p);
   
           for (p = word; *p; p++) {
                   c = TOLOWER(*p);
                   cnputc(ISLOWALPHA(c) && ABC_ISCLR(c) ? '-' : *p);
           }
   
   #ifdef ABC_WRONGSTR
           db_printf(" (%s)\r", ABC_WRONGSTR);
   #else
           db_printf(" (");
   
   #ifdef ABC_BITMASK
           m = sabc->wrong;
           for (i = 'a'; i <= 'z'; ++i, m >>= 1)
                   if (m&1)
                           cnputc(i);
   #else
           for (i = 'a'; i <= 'z'; ++i)
                   if (ABC_ISWRONG(i))
                           cnputc(i);
   #endif
   
           db_printf(")\r");
   #endif
   }
   
   void
   db_hangman(db_expr_t addr, int haddr, db_expr_t count, char *modif)
   {
           char    *word;
           size_t  tries;
           size_t  len;
           struct _abc sabc[1];
           int     skill, c;
   
           if (modif[0] != 's' || (skill = modif[1] - '') > 9U)
                   skill = 3;
           word = NULL;
           tries = 0;
           for (;;) {
   
                   if (word == NULL) {
                           ABC_CLR();
   
                           tries = skill + 1;
                           word = db_randomsym(&len);
                           if (word == NULL)
                                   break;
   
                           db_plays++;
                   }
                   db_hang(tries, word, sabc);
                   c = cngetc();
                   c = TOLOWER(c);
   
                   if (ISLOWALPHA(c) && ABC_ISCLR(c)) {
                           char    *p;
                           size_t  n;
   
                           /* strchr(word,c) */
                           for (n = 0, p = word; *p ; p++)
                                   if (TOLOWER(*p) == c)
                                           n++;
   
                           if (n) {
                                   ABC_SETRIGHT(c);
                                   len -= n;
                           } else {
                                   ABC_SETWRONG(c);
                                   tries--;
                           }
                   }
   
                   if (tries && len)
                           continue;
   
                   if (!tries && skill > 2) {
                           char    *p = word;
                           for (; *p; p++)
                                   if (ISALPHA(*p))
                                           ABC_SETRIGHT(TOLOWER(*p));
                   }
                   if (tries)
                           db_guesses++;
                   db_hang(tries, word, sabc);
                   db_printf("\nScore: %lu/%lu\n", db_plays, db_guesses);
                   word = NULL;
                   if (tries)
                           break;
           }
   }

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