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 1.5 2003/01/05 02:43:18 tjr Exp $ 13 * $DragonFly: src/lib/libc/stdlib/twalk.c,v 1.5 2005/11/24 17:18:30 swildner Exp $ 14 */ 15 16 #define _SEARCH_PRIVATE 17 #include <search.h> 18 #include <stdlib.h> 19 20 static void trecurse(const node_t *, 21 void (*action)(const void *, VISIT, int), int level); 22 23 /* 24 * Walk the nodes of a tree 25 * 26 * Parameters: 27 * root: Root of the tree to be walked 28 */ 29 static void 30 trecurse(const node_t *root, void (*action)(const void *, VISIT, int), 31 int level) 32 { 33 34 if (root->llink == NULL && root->rlink == NULL) 35 (*action)(root, leaf, level); 36 else { 37 (*action)(root, preorder, level); 38 if (root->llink != NULL) 39 trecurse(root->llink, action, level + 1); 40 (*action)(root, postorder, level); 41 if (root->rlink != NULL) 42 trecurse(root->rlink, action, level + 1); 43 (*action)(root, endorder, level); 44 } 45 } 46 47 /* 48 * Walk the nodes of a tree 49 * 50 * Parameters: 51 * vroot: Root of the tree to be walked 52 */ 53 void 54 twalk(const void *vroot, 55 void (*action)(const void *, VISIT, int)) 56 { 57 if (vroot != NULL && action != NULL) 58 trecurse(vroot, action, 0); 59 } 60