diff options
Diffstat (limited to 'lib/libc/stdlib/twalk.c')
| -rw-r--r-- | lib/libc/stdlib/twalk.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/lib/libc/stdlib/twalk.c b/lib/libc/stdlib/twalk.c new file mode 100644 index 000000000000..28529ea00adf --- /dev/null +++ b/lib/libc/stdlib/twalk.c @@ -0,0 +1,48 @@ +/* $NetBSD: twalk.c,v 1.4 2012/03/20 16:38:45 matt Exp $ */ + +/* + * Tree search generalized from Knuth (6.2.2) Algorithm T just like + * the AT&T man page says. + * + * Written by reading the System V Interface Definition, not the code. + * + * Totally public domain. + */ + +#include <sys/cdefs.h> +#if 0 +#if defined(LIBC_SCCS) && !defined(lint) +__RCSID("$NetBSD: twalk.c,v 1.4 2012/03/20 16:38:45 matt Exp $"); +#endif /* LIBC_SCCS and not lint */ +#endif +#define _SEARCH_PRIVATE +#include <search.h> +#include <stdlib.h> + +typedef void (*cmp_fn_t)(const posix_tnode *, VISIT, int); + +/* Walk the nodes of a tree */ +static void +trecurse(const posix_tnode *root, cmp_fn_t action, int level) +{ + + if (root->llink == NULL && root->rlink == NULL) + (*action)(root, leaf, level); + else { + (*action)(root, preorder, level); + if (root->llink != NULL) + trecurse(root->llink, action, level + 1); + (*action)(root, postorder, level); + if (root->rlink != NULL) + trecurse(root->rlink, action, level + 1); + (*action)(root, endorder, level); + } +} + +/* Walk the nodes of a tree */ +void +twalk(const posix_tnode *vroot, cmp_fn_t action) +{ + if (vroot != NULL && action != NULL) + trecurse(vroot, action, 0); +} |