blob: 72ba2617a1d73d8455f074f2c63bf7d3cd43094c (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
|
/*
* This file lifted in toto from 'Dlibs' on the atari ST (RdeBath)
*
*
* Dale Schumacher 399 Beacon Ave.
* (alias: Dalnefre') St. Paul, MN 55104
* dal@syntel.UUCP United States of America
* "It's not reality that's important, but how you perceive things."
*/
#include <stdio.h>
static int _bsearch; /* index of element found, or where to
* insert */
char *
bsearch(key, base, num, size, cmp)
register char *key; /* item to search for */
register char *base; /* base address */
int num; /* number of elements */
register int size; /* element size in bytes */
register int (*cmp) (); /* comparison function */
{
register int a, b, c, dir;
a = 0;
b = num - 1;
while (a <= b)
{
c = (a + b) >> 1; /* == ((a + b) / 2) */
if ((dir = (*cmp) ((base + (c * size)), key)))
{
if (dir > 0)
b = c - 1;
else /* (dir < 0) */
a = c + 1;
}
else
{
_bsearch = c;
return (base + (c * size));
}
}
_bsearch = b;
return (NULL);
}
|