BSD 3 release

[unix-history] / usr / src / cmd / look.c

#include <stdio.h>
#include <ctype.h>

FILE *dfile;
char *filenam  = "/usr/dict/words";

int fold;
int dict;
int tab;
char entry[250];
char word[250];
char key[50];

main(argc,argv)
char **argv;
{
       register c;
       long top,bot,mid;
       while(argc>=2 && *argv[1]=='-') {
               for(;;) {
                       switch(*++argv[1]) {
                       case 'd':
                               dict++;
                               continue;
                       case 'f':
                               fold++;
                               continue;
                       case 't':
                               tab = argv[1][1];
                               if(tab)
                                       ++argv[1];
                               continue;
                       case 0:
                               break;
                       default:
                               continue;
                       }
                       break;
               }
               argc --;
               argv++;
       }
       if(argc<=1)
               return;
       if(argc==2) {
               fold++;
               dict++;
       } else
               filenam = argv[2];
       dfile = fopen(filenam,"r");
       if(dfile==NULL) {
               fprintf(stderr,"look: can't open %s\n",filenam);
               exit(2);
       }
       canon(argv[1],key);
       bot = 0;
       fseek(dfile,0L,2);
       top = ftell(dfile);
       for(;;) {
               mid = (top+bot)/2;
               fseek(dfile,mid,0);
               do {
                       c = getc(dfile);
                       mid++;
               } while(c!=EOF && c!='\n');
               if(!getword(entry))
                       break;
               canon(entry,word);
               switch(compare(key,word)) {
               case -2:
               case -1:
               case 0:
                       if(top<=mid)
                               break;
                       top = mid;
                       continue;
               case 1:
               case 2:
                       bot = mid;
                       continue;
               }
               break;
       }
       fseek(dfile,bot,0);
       while(ftell(dfile)<top) {
               if(!getword(entry))
                       return;
               canon(entry,word);
               switch(compare(key,word)) {
               case -2:
                       return;
               case -1:
               case 0:
                       puts(entry,stdout);
                       break;
               case 1:
               case 2:
                       continue;
               }
               break;
       }
       while(getword(entry)) {
               canon(entry,word);
               switch(compare(key,word)) {
               case -1:
               case 0:
                       puts(entry,stdout);
                       continue;
               }
               break;
       }
}

compare(s,t)
register char *s,*t;
{
       for(;*s==*t;s++,t++)
               if(*s==0)
                       return(0);
       return(*s==0? -1:
               *t==0? 1:
               *s<*t? -2:
               2);
}

getword(w)
char *w;
{
       register c;
       for(;;) {
               c = getc(dfile);
               if(c==EOF)
                       return(0);
               if(c=='\n')
                       break;
               *w++ = c;
       }
       *w = 0;
       return(1);
}

canon(old,new)
char *old,*new;
{
       register c;
       for(;;) {
               *new = c = *old++;
               if(c==0||c==tab) {
                       *new = 0;
                       break;
               }
               if(dict) {
                       if(!isalnum(c))
                               continue;
               }
               if(fold) {
                       if(isupper(c))
                               *new += 'a' - 'A';
               }
               new++;
       }
}