4.3BSD - /usr/src/usr.bin/refer/what4.c

   1: #ifndef lint
   2: static char *sccsid = "@(#)what4.c	4.1 (Berkeley) 5/6/83";
   3: #endif
   4: 
   5: #include "what..c"
   6: #define NW 5
   7: #define ZIPF 10
   8: #define HASHF 3
   9: #define WLEN 10
  10: #define SAME 0
  11: #define TSIZE HASHF*ZIPF*NW
  12: #define NF 10
  13: 
  14: struct wst {
  15:     char *tx;
  16:     int ct;
  17: }
  18: ;
  19: int HSIZE;
  20: static struct wst word[TSIZE];
  21: static char tbuf[NW*ZIPF*WLEN], *tp tbuf;
  22: 
  23: freqwd ( fn, wd, nin )
  24: char *fn[], *wd[];
  25: {
  26:     FILE *fi[NF];
  27:     int nw 0, i, any, nf, j, wexch(), wcomp();
  28:     char tw[20];
  29:     for(HSIZE=TSIZE; !prime(HSIZE); HSIZE--);
  30:     for(nf=0; fn[nf] && nf<NF; nf++)
  31:         fi[nf] = fn[nf][0] ? fopen(fn[nf], "r") : NULL;
  32:     do {
  33:         any=0;
  34:         for(i=0; i<nf; i++)
  35:         {
  36:             if (fi[i]==NULL) continue;
  37:             if (gw(fi[i], tw)==0)
  38:             {
  39:                 fclose(fi[i]);
  40:                 fi[i]==NULL;
  41:                 continue;
  42:             }
  43:             any=1;
  44:             if (common(tw)) continue;
  45:             if (strlen(tw)<3) continue;
  46:             j = lookup (tw);
  47:             if (j<0 && nw < ZIPF*NW)
  48:             {
  49:                 j = -j;
  50:                 strcpy (tp, tw);
  51:                 word[j].tx = tp;
  52:                 while (*tp++);
  53:                 _assert (tp < tbuf+NW*ZIPF*WLEN);
  54:                 word[j].ct = 1;
  55:                 nw++;
  56:             }
  57:             else if (j>0)
  58:                 word[j].ct++;
  59:         }
  60:     }
  61:     while (any>0);
  62:     shell ( TSIZE, wcomp, wexch );
  63:     for(nw=0; word[nw].ct >0 && nw<TSIZE; nw++)
  64:         if (nw>=nin*2 && word[nw].ct != word[0].ct)
  65:             break;
  66:     for(i=0; i<nw; i++)
  67:         wd[i] = word[i].tx;
  68:     return(nw);
  69: }
  70: 
  71: lookup (wt)
  72: char *wt;
  73: {
  74:     int h;
  75:     h = hash(wt);
  76:     for( h = h%HSIZE; word[h].tx; h = (h+1)%HSIZE)
  77:     {
  78:         if (h==0) continue;
  79:         if (strcmp(wt, word[h].tx) == SAME)
  80:             return (h);
  81:     }
  82:     return ( -h );
  83: }
  84: 
  85: hash (s)
  86: char *s;
  87: {
  88:     int k 0, c 0, i 0;
  89:     while ( c = *s++ )
  90:         k ^= (c << (i++%5) );
  91:     return (k>0 ? k : -k);
  92: }
  93: 
  94: gw (f, t)
  95: char *t;
  96: FILE *f;
  97: {
  98:     int start 1, oldc ' ', c;
  99:     if (f==NULL) return (0);
 100:     while ( (c=getc(f)) != EOF)
 101:     {
 102:         if (isupper(c)) c= tolower(c);
 103:         if (start==1)
 104:             if (!alphanum(c, oldc))
 105:                 continue;
 106:             else
 107:                 start=0;
 108:         if (start==0)
 109:             if (alphanum(c, oldc))
 110:                 *t++ = c;
 111:             else
 112:             {
 113:                 *t=0;
 114:                 return(1);
 115:             }
 116:         oldc=c;
 117:     }
 118:     return(0);
 119: }
 120: 
 121: alphanum( c, oldc )
 122: {
 123:     if (isalpha(c) || isdigit(c)) return(1);
 124:     if (isalpha(oldc))
 125:         if (c== '\'' || c == '-') return(1);
 126:     return(0);
 127: }
 128: 
 129: wcomp (n1, n2)
 130: {
 131:     return (word[n1].ct >= word[n2].ct);
 132: }
 133: 
 134: wexch (n1, n2)
 135: {
 136:     struct wst tt;
 137:     tt.tx = word[n1].tx;
 138:     tt.ct = word[n1].ct;
 139:     word[n1].tx = word[n2].tx;
 140:     word[n1].ct = word[n2].ct;
 141:     word[n2].tx = tt.tx;
 142:     word[n2].ct = tt.ct;
 143: }
 144: 
 145: prime(n)
 146: {
 147:     /* only executed once- slow is ok */
 148:     int i;
 149:     if (n%2==0) return(0);
 150:     for(i=3; i*i<=n; i+= 2)
 151:         if (n%i ==0 ) return(0);
 152:     return(1);
 153: }
 154: 
 155: trimnl(s)
 156: char *s;
 157: {
 158:     while (*s)s++;
 159:     if (*--s=='\n') *s=0;
 160: }
 161: 
 162: /* this is the test for what4.c as a standalone prog ... */
 163: # ifdef 0
 164: main (argc, argv)
 165: char *argv[];
 166: {
 167:     char *ff[10], *wd[20], **ffp ff;
 168:     int n, i;
 169: 
 170:     while (--argc)
 171:         *ffp++ = *++argv;
 172:     *ffp=0;
 173:     n=freqwd(ff,wd);
 174:     for(i=0; i<n; i++)
 175:         printf("%s\n",wd[i]);
 176:     printf("total of %d items\n",n);
 177: }
 178: # endif 0

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