1 /* look 1.3 - Find lines in a sorted list. Author: Kees J. Bot
2 */
3 #define nil 0
4 #include <sys/types.h>
5 #include <stdio.h>
6 #include <ctype.h>
7 #include <stdlib.h>
8 #include <string.h>
9
10 char DEFAULT[] = "/usr/lib/dict/words";
11
12 char *string, *wordlist= DEFAULT;
13
14 #define MAXLEN 1024 /* Maximum word length. */
15
16 int dflg= 0, fflg= 0;
17
nonascii(char * what)18 void nonascii(char *what)
19 {
20 fprintf(stderr, "look: %s contains non-ASCII characters.\n", what);
21 exit(1);
22 }
23
compare(char * prefix,char * word)24 int compare(char *prefix, char *word)
25 {
26 char *p= prefix, *w= word;
27 int cp, cw;
28
29 do {
30 do {
31 if ((cp= *p++) == 0) return 0;
32 if (!isascii(cp)) nonascii("prefix string");
33 } while (dflg && !isspace(cp) && !isalnum(cp));
34
35 if (dflg) {
36 if (isspace(cp)) {
37 while (isspace(*p)) p++;
38 cp= ' ';
39 }
40 }
41 if (fflg && isupper(cp)) cp= tolower(cp);
42
43 do {
44 if ((cw= *w++) == 0) return 1;
45 if (!isascii(cw)) nonascii(wordlist);
46 } while (dflg && !isspace(cw) && !isalnum(cw));
47
48 if (dflg) {
49 if (isspace(cw)) {
50 while (isspace(*w)) w++;
51 cw= ' ';
52 }
53 }
54 if (fflg && isupper(cw)) cw= tolower(cw);
55 } while (cp == cw);
56
57 return cp - cw;
58 }
59
readword(FILE * f)60 char *readword(FILE *f)
61 {
62 static char word[MAXLEN + 2];
63 int n;
64
65 if (fgets(word, sizeof(word), f) == nil) {
66 if (ferror(f)) {
67 fprintf(stderr, "look: read error on %s",
68 wordlist);
69 exit(1);
70 }
71 return nil;
72 }
73
74 n= strlen(word);
75
76 if (word[n-1] != '\n') {
77 fprintf(stderr, "look: word from %s is too long\n", wordlist);
78 exit(1);
79 }
80 word[n-1] = 0;
81
82 return word;
83 }
84
look(void)85 void look(void)
86 {
87 off_t low, mid, high;
88 FILE *f;
89 char *word;
90 int c;
91
92 if ((f= fopen(wordlist, "r")) == nil) {
93 fprintf(stderr, "look: Can't open %s\n", wordlist);
94 exit(1);
95 }
96
97 low= 0;
98
99 fseek(f, (off_t) 0, 2);
100
101 high= ftell(f);
102
103 while (low <= high) {
104 mid= (low + high) / 2;
105
106 fseek(f, mid, 0);
107
108 if (mid != 0) readword(f);
109
110 if ((word= readword(f)) == nil)
111 c= -1;
112 else
113 c= compare(string, word);
114
115 if (c <= 0) high= mid - 1; else low= mid + 1;
116 }
117 fseek(f, low, 0);
118 if (low != 0) readword(f);
119
120 c=0;
121 while (c >= 0 && (word= readword(f)) != nil) {
122 c= compare(string, word);
123
124 if (c == 0) puts(word);
125 }
126 }
127
main(int argc,char ** argv)128 int main(int argc, char **argv)
129 {
130 if (argc == 2) dflg= fflg= 1;
131
132 while (argc > 1 && argv[1][0] == '-') {
133 char *p= argv[1] + 1;
134
135 while (*p != 0) {
136 switch (*p++) {
137 case 'd': dflg= 1; break;
138 case 'f': fflg= 1; break;
139 default:
140 fprintf(stderr, "look: Bad flag: %c\n", p[-1]);
141 exit(1);
142 }
143 }
144 argc--;
145 argv++;
146 }
147 if (argc == 3)
148 wordlist= argv[2];
149 else
150 if (argc != 2) {
151 fprintf(stderr, "Usage: look [-df] string [file]\n");
152 exit(1);
153 }
154 string= argv[1];
155 look();
156 exit(0);
157 }
158 /* Kees J. Bot 24-5-89. */
159