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/* look 1.3 - Find lines in a sorted list. Author: Kees J. Bot
*/
#define nil 0
#include <sys/types.h>
#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
char DEFAULT[] = "/usr/lib/dict/words";
char *string, *wordlist= DEFAULT;
#define MAXLEN 1024 /* Maximum word length. */
int dflg= 0, fflg= 0;
void nonascii(char *what)
{
fprintf(stderr, "look: %s contains non-ASCII characters.\n", what);
exit(1);
}
int compare(char *prefix, char *word)
{
char *p= prefix, *w= word;
int cp, cw;
do {
do {
if ((cp= *p++) == 0) return 0;
if (!isascii(cp)) nonascii("prefix string");
} while (dflg && !isspace(cp) && !isalnum(cp));
if (dflg) {
if (isspace(cp)) {
while (isspace(*p)) p++;
cp= ' ';
}
}
if (fflg && isupper(cp)) cp= tolower(cp);
do {
if ((cw= *w++) == 0) return 1;
if (!isascii(cw)) nonascii(wordlist);
} while (dflg && !isspace(cw) && !isalnum(cw));
if (dflg) {
if (isspace(cw)) {
while (isspace(*w)) w++;
cw= ' ';
}
}
if (fflg && isupper(cw)) cw= tolower(cw);
} while (cp == cw);
return cp - cw;
}
char *readword(FILE *f)
{
static char word[MAXLEN + 2];
int n;
if (fgets(word, sizeof(word), f) == nil) {
if (ferror(f)) {
fprintf(stderr, "look: read error on %s",
wordlist);
exit(1);
}
return nil;
}
n= strlen(word);
if (word[n-1] != '\n') {
fprintf(stderr, "look: word from %s is too long\n", wordlist);
exit(1);
}
word[n-1] = 0;
return word;
}
void look(void)
{
off_t low, mid, high;
FILE *f;
char *word;
int c;
if ((f= fopen(wordlist, "r")) == nil) {
fprintf(stderr, "look: Can't open %s\n", wordlist);
exit(1);
}
low= 0;
fseek(f, (off_t) 0, 2);
high= ftell(f);
while (low <= high) {
mid= (low + high) / 2;
fseek(f, mid, 0);
if (mid != 0) readword(f);
if ((word= readword(f)) == nil)
c= -1;
else
c= compare(string, word);
if (c <= 0) high= mid - 1; else low= mid + 1;
}
fseek(f, low, 0);
if (low != 0) readword(f);
c=0;
while (c >= 0 && (word= readword(f)) != nil) {
c= compare(string, word);
if (c == 0) puts(word);
}
}
int main(int argc, char **argv)
{
if (argc == 2) dflg= fflg= 1;
while (argc > 1 && argv[1][0] == '-') {
char *p= argv[1] + 1;
while (*p != 0) {
switch (*p++) {
case 'd': dflg= 1; break;
case 'f': fflg= 1; break;
default:
fprintf(stderr, "look: Bad flag: %c\n", p[-1]);
exit(1);
}
}
argc--;
argv++;
}
if (argc == 3)
wordlist= argv[2];
else
if (argc != 2) {
fprintf(stderr, "Usage: look [-df] string [file]\n");
exit(1);
}
string= argv[1];
look();
exit(0);
}
/* Kees J. Bot 24-5-89. */
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