1 /* $NetBSD: twalk.c,v 1.1 1999/02/22 10:33:16 christos 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 1.1 1999/02/22 10:33:16 christos Exp $"); 17 #endif /* LIBC_SCCS and not lint */ 18 19 #define _SEARCH_PRIVATE 20 #include <search.h> 21 #include <stdlib.h> 22 23 static void trecurse __P((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(root, action, level) 29 const node_t *root; /* Root of the tree to be walked */ 30 void (*action) __P((const void *, VISIT, int)); 31 int level; 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(vroot, action) 49 const void *vroot; /* Root of the tree to be walked */ 50 void (*action) __P((const void *, VISIT, int)); 51 { 52 if (vroot != NULL && action != NULL) 53 trecurse(vroot, action, 0); 54 } 55