usr/src/cmd/look/look.c

   1 /*
   2  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
   3  * Use is subject to license terms.
   4  */
   5
   6 /*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
   7 /*        All Rights Reserved   */
   8
   9 /*
  10  * Copyright (c) 1980 Regents of the University of California.
  11  * All rights reserved. The Berkeley software License Agreement
  12  * specifies the terms and conditions for redistribution.
  13  */
  14
  15 #include <stdlib.h>
  16 #include <stdio.h>
  17 #include <ctype.h>
  18 #include <string.h>
  19
  20 FILE *dfile;
  21 char *filenam  = "/usr/share/lib/dict/words";
  22
  23 int fold;
  24 int dict;
  25 int tab;
  26 #define WORDSIZE 257
  27 char entry[WORDSIZE];
  28 char word[WORDSIZE];
  29 char key[WORDSIZE];
  30
  31 int     compare(char *, char *);
  32 void    canon(char *, char *);
  33 int     getword(char *);
  34
  35 int
  36 main(int argc, char **argv)
  37 {
  38         int c;
  39         long top, bot, mid;
  40         char *wstring, *ptr;
  41
  42         while (argc >= 2 && *argv[1] == '-') {
  43                 for (;;) {
  44                         switch (*++argv[1]) {
  45                         case 'd':
  46                                 dict++;
  47                                 continue;
  48                         case 'f':
  49                                 fold++;
  50                                 continue;
  51                         case 't':
  52                                 tab = argv[1][1];
  53                                 if (tab)
  54                                         ++argv[1];
  55                                 continue;
  56                         case 0:
  57                                 break;
  58                         default:
  59                                 continue;
  60                         }
  61                         break;
  62                 }
  63                 argc --;
  64                 argv++;
  65         }
  66         if (argc <= 1)
  67                 return (1);
  68         if (argc == 2) {
  69                 fold++;
  70                 dict++;
  71         } else
  72                 filenam = argv[2];
  73         dfile = fopen(filenam, "r");
  74         if (dfile == NULL) {
  75                 (void) fprintf(stderr, "look: can't open %s\n", filenam);
  76                 exit(2);
  77         }
  78         wstring = strdup(argv[1]);
  79         if (tab != 0) {
  80                 if ((ptr = strchr(wstring, tab)) != NULL) {
  81                         *++ptr = '\0';
  82                 }
  83         }
  84         canon(wstring, key);
  85         bot = 0;
  86         (void) fseek(dfile, 0L, 2);
  87         top = ftell(dfile);
  88         for (;;) {
  89                 mid = (top+bot)/2;
  90                 (void) fseek(dfile, mid, 0);
  91                 do {
  92                         c = getc(dfile);
  93                         mid++;
  94                 } while (c != EOF && c != '\n');
  95                 if (!getword(entry))
  96                         break;
  97                 canon(entry, word);
  98                 switch (compare(key, word)) {
  99                 case -2:
 100                 case -1:
 101                 case 0:
 102                         if (top <= mid)
 103                                 break;
 104                         top = mid;
 105                         continue;
 106                 case 1:
 107                 case 2:
 108                         bot = mid;
 109                         continue;
 110                 }
 111                 break;
 112         }
 113         (void) fseek(dfile, bot, 0);
 114         while (ftell(dfile) < top) {
 115                 if (!getword(entry))
 116                         return (0);
 117                 canon(entry, word);
 118                 switch (compare(key, word)) {
 119                 case -2:
 120                         return (0);
 121                 case -1:
 122                 case 0:
 123                         (void) puts(entry);
 124                         break;
 125                 case 1:
 126                 case 2:
 127                         continue;
 128                 }
 129                 break;
 130         }
 131         while (getword(entry)) {
 132                 canon(entry, word);
 133                 switch (compare(key, word)) {
 134                 case -1:
 135                 case 0:
 136                         (void) puts(entry);
 137                         continue;
 138                 }
 139                 break;
 140         }
 141         return (0);
 142 }
 143
 144 int
 145 compare(char *s, char *t)
 146 {
 147         for (; *s == *t; s++, t++)
 148                 if (*s == 0)
 149                         return (0);
 150         return (*s == 0? -1:
 151             *t == 0? 1:
 152             *s < *t? -2: 2);
 153 }
 154
 155 int
 156 getword(char *w)
 157 {
 158         int c;
 159         int avail = WORDSIZE - 1;
 160
 161         while (avail--) {
 162                 c = getc(dfile);
 163                 if (c == EOF)
 164                         return (0);
 165                 if (c == '\n')
 166                         break;
 167                 *w++ = c;
 168         }
 169         while (c != '\n')
 170                 c = getc(dfile);
 171         *w = 0;
 172         return (1);
 173 }
 174
 175 void
 176 canon(char *old, char *new)
 177 {
 178         int c;
 179         int avail = WORDSIZE - 1;
 180
 181         for (;;) {
 182                 *new = c = *old++;
 183                 if (c == 0) {
 184                         *new = 0;
 185                         break;
 186                 }
 187                 if (dict) {
 188                         if (!isalnum(c))
 189                                 continue;
 190                 }
 191                 if (fold) {
 192                         if (isupper(c))
 193                                 *new += 'a' - 'A';
 194                 }
 195                 new++;
 196                 avail--;
 197                 if (avail <= 0) {
 198                         *new = 0;
 199                         break;
 200                 }
 201         }
 202 }