1 /*********************************************************************** 2 * * 3 * This software is part of the ast package * 4 * Copyright (c) 1985-2007 AT&T Knowledge Ventures * 5 * and is licensed under the * 6 * Common Public License, Version 1.0 * 7 * by AT&T Knowledge Ventures * 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* 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