1 /* 2 * Tree search generalized from Knuth (6.2.2) Algorithm T just like 3 * the AT&T man page says. 4 * 5 * The node_t structure is for internal use only, lint doesn't grok it. 6 * 7 * Written by reading the System V Interface Definition, not the code. 8 * 9 * Totally public domain. 10 * 11 * $NetBSD: twalk.c,v 1.1 1999/02/22 10:33:16 christos Exp $ 12 * $FreeBSD: src/lib/libc/stdlib/twalk.c,v 1.1.2.1 2000/08/17 07:38:39 jhb Exp $ 13 * $DragonFly: src/lib/libc/stdlib/twalk.c,v 1.4 2005/11/20 12:37:49 swildner Exp $ 14 */ 15 16 #include <sys/cdefs.h> 17 18 #include <assert.h> 19 #define _SEARCH_PRIVATE 20 #include <search.h> 21 #include <stdlib.h> 22 23 static void trecurse (const node_t *, 24 void (*action)(const void *, VISIT, int), int level); 25 26 /* Walk the nodes of a tree */ 27 static void 28 trecurse(const node_t *root, /* Root of the tree to be walked */ 29 void (*action)(const void *, VISIT, int), 30 int level) 31 { 32 33 if (root->llink == NULL && root->rlink == NULL) 34 (*action)(root, leaf, level); 35 else { 36 (*action)(root, preorder, level); 37 if (root->llink != NULL) 38 trecurse(root->llink, action, level + 1); 39 (*action)(root, postorder, level); 40 if (root->rlink != NULL) 41 trecurse(root->rlink, action, level + 1); 42 (*action)(root, endorder, level); 43 } 44 } 45 46 /* Walk the nodes of a tree */ 47 void 48 twalk(const void *vroot, /* Root of the tree to be walked */ 49 void (*action)(const void *, VISIT, int)) 50 { 51 if (vroot != NULL && action != NULL) 52 trecurse(vroot, action, 0); 53 } 54