/*
 * This module contains the code for searching the FFS tree structure
 * for a specified absolute pathname.
 */

#include <sys/types.h>
#include <ctype.h>
#include <stdio.h>
#include <string.h>
#include <strings.h>
#include <stdlib.h>
#include <unistd.h>
#include "types.h"
#include "struct.h"

extern int root_node_no;

/*
 * The following function iterates through the descendants of a directory
 * object looking for a specific directory-member filename.
 *
 * Arguments:
 * - index # of the first descendant (descendant pointer from the dir object)
 * - filename to search for
 *
 * Returns: index # of the sought descendant object if found, 0 otherwise.
 */
find_dir_member(first_descend, srchname)
	char *srchname;
{
	int ent;
	struct objinfo obj;

	for (ent = first_descend; ent != 0xFFFF; ent = obj.sibling) {
		obj.entryno = ent;
		get_index_entry(&obj);
		if (!obj.type) /* skip deleted objects w/o further looking */
			continue;
		validate_chunk(&obj);
		validate_obj_name(&obj);
		if (!strcmp(obj.dataptr, srchname))
			return(ent);
	}
	return(0);
}

/*
 * The following function searches for a pathname from the root down.
 * Returns the index # if found, otherwise exits with an error message
 * indicating which step failed.
 *
 * Warning: the pathname in the argument buffer will be destroyed:
 * 0s put in place of the slashes.
 */
find_pathname(pathname)
	char *pathname;
{
	char *cur, *next;
	int idx;
	struct objinfo dir;

	cur = pathname;
	if (*cur == '/')
		cur++;
	for (idx = root_node_no; cur; cur = next) {
		if (!*cur)
			break;
		next = index(cur, '/');
		if (next == cur) {
			fprintf(stderr,
			"malformed pathname: multiple adjacent slashes\n");
			exit(1);
		}
		if (next)
			*next++ = '\0';
		dir.entryno = idx;
		get_index_entry(&dir);
		if (dir.type != 0xF2) {
			fprintf(stderr,
			"pathname search error: encountered a non-directory\n");
			exit(1);
		}
		idx = find_dir_member(dir.descend, cur);
		if (!idx) {
			fprintf(stderr,
			"pathname search error: component name not found\n");
			exit(1);
		}
	}
	return(idx);
}