1 /* $NetBSD: tfind.c,v 1.2 1999/09/16 11:45:37 lukem Exp $ */ 2 3 /* 4 * Tree search generalized from Knuth (6.2.2) Algorithm T just like 5 * the AT&T man page says. 6 * 7 * Written by reading the System V Interface Definition, not the code. 8 * 9 * Totally public domain. 10 */ 11 12 #include <sys/cdefs.h> 13 #if 0 14 #if defined(LIBC_SCCS) && !defined(lint) 15 __RCSID("$NetBSD: tfind.c,v 1.2 1999/09/16 11:45:37 lukem Exp $"); 16 #endif /* LIBC_SCCS and not lint */ 17 #endif 18 #define _SEARCH_PRIVATE 19 #include <stdlib.h> 20 #include <search.h> 21 22 /* 23 * find a node, or return 0 24 * 25 * vkey - key to be found 26 * vrootp - address of the tree root 27 */ 28 posix_tnode * 29 tfind(const void *vkey, posix_tnode * const *rootp, 30 int (*compar)(const void *, const void *)) 31 { 32 33 if (rootp == NULL) 34 return NULL; 35 36 while (*rootp != NULL) { /* T1: */ 37 int r; 38 39 if ((r = (*compar)(vkey, (*rootp)->key)) == 0) /* T2: */ 40 return *rootp; /* key found */ 41 rootp = (r < 0) ? 42 &(*rootp)->llink : /* T3: follow left branch */ 43 &(*rootp)->rlink; /* T4: follow right branch */ 44 } 45 return NULL; 46 } 47