2.9BSD - /usr/src/cmd/look.c

   1: #include <stdio.h>
   2: #include <ctype.h>
   3: 
   4: FILE *dfile;
   5: char *filenam  = "/usr/dict/words";
   6: 
   7: int fold;
   8: int dict;
   9: int tab;
  10: char entry[250];
  11: char word[250];
  12: char key[50];
  13: 
  14: main(argc,argv)
  15: char **argv;
  16: {
  17:     register c;
  18:     long top,bot,mid;
  19:     while(argc>=2 && *argv[1]=='-') {
  20:         for(;;) {
  21:             switch(*++argv[1]) {
  22:             case 'd':
  23:                 dict++;
  24:                 continue;
  25:             case 'f':
  26:                 fold++;
  27:                 continue;
  28:             case 't':
  29:                 tab = argv[1][1];
  30:                 if(tab)
  31:                     ++argv[1];
  32:                 continue;
  33:             case 0:
  34:                 break;
  35:             default:
  36:                 continue;
  37:             }
  38:             break;
  39:         }
  40:         argc --;
  41:         argv++;
  42:     }
  43:     if(argc<=1)
  44:         return;
  45:     if(argc==2) {
  46:         fold++;
  47:         dict++;
  48:     } else
  49:         filenam = argv[2];
  50:     dfile = fopen(filenam,"r");
  51:     if(dfile==NULL) {
  52:         fprintf(stderr,"look: can't open %s\n",filenam);
  53:         exit(2);
  54:     }
  55:     canon(argv[1],key);
  56:     bot = 0;
  57:     fseek(dfile,0L,2);
  58:     top = ftell(dfile);
  59:     for(;;) {
  60:         mid = (top+bot)/2;
  61:         fseek(dfile,mid,0);
  62:         do {
  63:             c = getc(dfile);
  64:             mid++;
  65:         } while(c!=EOF && c!='\n');
  66:         if(!getword(entry))
  67:             break;
  68:         canon(entry,word);
  69:         switch(compare(key,word)) {
  70:         case -2:
  71:         case -1:
  72:         case 0:
  73:             if(top<=mid)
  74:                 break;
  75:             top = mid;
  76:             continue;
  77:         case 1:
  78:         case 2:
  79:             bot = mid;
  80:             continue;
  81:         }
  82:         break;
  83:     }
  84:     fseek(dfile,bot,0);
  85:     while(ftell(dfile)<top) {
  86:         if(!getword(entry))
  87:             return;
  88:         canon(entry,word);
  89:         switch(compare(key,word)) {
  90:         case -2:
  91:             return;
  92:         case -1:
  93:         case 0:
  94:             puts(entry,stdout);
  95:             break;
  96:         case 1:
  97:         case 2:
  98:             continue;
  99:         }
 100:         break;
 101:     }
 102:     while(getword(entry)) {
 103:         canon(entry,word);
 104:         switch(compare(key,word)) {
 105:         case -1:
 106:         case 0:
 107:             puts(entry,stdout);
 108:             continue;
 109:         }
 110:         break;
 111:     }
 112: }
 113: 
 114: compare(s,t)
 115: register char *s,*t;
 116: {
 117:     for(;*s==*t;s++,t++)
 118:         if(*s==0)
 119:             return(0);
 120:     return(*s==0? -1:
 121:         *t==0? 1:
 122:         *s<*t? -2:
 123:         2);
 124: }
 125: 
 126: getword(w)
 127: char *w;
 128: {
 129:     register c;
 130:     for(;;) {
 131:         c = getc(dfile);
 132:         if(c==EOF)
 133:             return(0);
 134:         if(c=='\n')
 135:             break;
 136:         *w++ = c;
 137:     }
 138:     *w = 0;
 139:     return(1);
 140: }
 141: 
 142: canon(old,new)
 143: char *old,*new;
 144: {
 145:     register c;
 146:     for(;;) {
 147:         *new = c = *old++;
 148:         if(c==0||c==tab) {
 149:             *new = 0;
 150:             break;
 151:         }
 152:         if(dict) {
 153:             if(!isalnum(c))
 154:                 continue;
 155:         }
 156:         if(fold) {
 157:             if(isupper(c))
 158:                 *new += 'a' - 'A';
 159:         }
 160:         new++;
 161:     }
 162: }

Defined functions

Defined variables