1 /***********************************************************************
2 * *
3 * This software is part of the ast package *
4 * Copyright (c) 1985-2010 AT&T Intellectual Property *
5 * and is licensed under the *
6 * Common Public License, Version 1.0 *
7 * by AT&T Intellectual Property *
8 * *
9 * A copy of the License is available at *
10 * http://www.opensource.org/licenses/cpl1.0.txt *
11 * (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9) *
12 * *
13 * Information and Software Systems Research *
14 * AT&T Research *
15 * Florham Park NJ *
16 * *
17 * Glenn Fowler <gsf@research.att.com> *
18 * David Korn <dgk@research.att.com> *
19 * Phong Vo <kpv@research.att.com> *
20 * *
21 ***********************************************************************/
22 #pragma prototyped
23 /*
24 * Glenn Fowler
25 * AT&T Research
26 */
27
28 #include <ast.h>
29
30 /*
31 * return a pointer to the element matching
32 * name in the (*comparf*)() sorted tab of num elements of
33 * size siz where the first member of each
34 * element is a char*
35 *
36 * 0 returned if name not found
37 */
38
39 void*
strsearch(const void * tab,size_t num,size_t siz,Strcmp_f comparf,const char * name,void * context)40 strsearch(const void* tab, size_t num, size_t siz, Strcmp_f comparf, const char* name, void* context)
41 {
42 register char* lo = (char*)tab;
43 register char* hi = lo + (num - 1) * siz;
44 register char* mid;
45 register int v;
46
47 while (lo <= hi)
48 {
49 mid = lo + (((hi - lo) / siz) / 2) * siz;
50 if (!(v = context ? (*(Strcmp_context_f)comparf)(name, *((char**)mid), context) : (*comparf)(name, *((char**)mid))))
51 return (void*)mid;
52 else if (v > 0)
53 lo = mid + siz;
54 else hi = mid - siz;
55 }
56 return 0;
57 }
58