1 /* $NetBSD: twalk.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 * The node_t structure is for internal use only, lint doesn't grok it. 8 * 9 * Written by reading the System V Interface Definition, not the code. 10 * 11 * Totally public domain. 12 */ 13 14 #include <sys/cdefs.h> 15 #if defined(LIBC_SCCS) && !defined(lint) 16 __RCSID("$NetBSD: twalk.c,v 1.2 1999/09/16 11:45:37 lukem Exp $"); 17 #endif /* LIBC_SCCS and not lint */ 18 19 #include <assert.h> 20 #define _SEARCH_PRIVATE 21 #include <search.h> 22 #include <stdlib.h> 23 24 static void trecurse __P((const node_t *, 25 void (*action)(const void *, VISIT, int), int level)); 26 27 /* Walk the nodes of a tree */ 28 static void 29 trecurse(root, action, level) 30 const node_t *root; /* Root of the tree to be walked */ 31 void (*action) __P((const void *, VISIT, int)); 32 int level; 33 { 34 _DIAGASSERT(root != NULL); 35 _DIAGASSERT(action != NULL); 36 37 if (root->llink == NULL && root->rlink == NULL) 38 (*action)(root, leaf, level); 39 else { 40 (*action)(root, preorder, level); 41 if (root->llink != NULL) 42 trecurse(root->llink, action, level + 1); 43 (*action)(root, postorder, level); 44 if (root->rlink != NULL) 45 trecurse(root->rlink, action, level + 1); 46 (*action)(root, endorder, level); 47 } 48 } 49 50 /* Walk the nodes of a tree */ 51 void 52 twalk(vroot, action) 53 const void *vroot; /* Root of the tree to be walked */ 54 void (*action) __P((const void *, VISIT, int)); 55 { 56 if (vroot != NULL && action != NULL) 57 trecurse(vroot, action, 0); 58 } 59