/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*        All Rights Reserved   */

/*
 * Copyright (c) 1980 Regents of the University of California.
 * All rights reserved. The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 */

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

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

int fold;
int dict;
int tab;
#define WORDSIZE 257
char entry[WORDSIZE];
char word[WORDSIZE];
char key[WORDSIZE];

int     compare(char *, char *);
void    canon(char *, char *);
int     getword(char *);

int
main(int argc, char **argv)
{
        int c;
        long top,bot,mid;
        char *wstring, *ptr;

        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 (1);
        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);
        }
        wstring = strdup(argv[1]);
        if (tab != 0) {
                if ((ptr = strchr(wstring, tab)) != NULL) {
                        *++ptr = '\0';
                }
        }
        canon(wstring,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 (0);
                canon(entry,word);
                switch(compare(key,word)) {
                case -2:
                        return (0);
                case -1:
                case 0:
                        puts(entry);
                        break;
                case 1:
                case 2:
                        continue;
                }
                break;
        }
        while(getword(entry)) {
                canon(entry,word);
                switch(compare(key,word)) {
                case -1:
                case 0:
                        puts(entry);
                        continue;
                }
                break;
        }
        return (0);
}

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

int
getword(char *w)
{
        int c;
        int avail = WORDSIZE - 1;

        while(avail--) {
                c = getc(dfile);
                if(c==EOF)
                        return(0);
                if(c=='\n')
                        break;
                *w++ = c;
        }
        while (c != '\n')
                c = getc(dfile);
        *w = 0;
        return(1);
}

void
canon(char *old, char *new)
{
        int c;
        int avail = WORDSIZE - 1;

        for(;;) {
                *new = c = *old++;
                if(c==0) {
                        *new = 0;
                        break;
                }
                if(dict) {
                        if(!isalnum(c))
                                continue;
                }
                if(fold) {
                        if(isupper(c))
                                *new += 'a' - 'A';
                }
                new++;
                avail--;
                if (avail <= 0) {
                        *new = 0;
                        break;
                }
        }
}