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/*********************************************************************
* bfs *
* Copyright (C) 2015-2016 Tavian Barnes <tavianator@tavianator.com> *
* *
* This program is free software. It comes without any warranty, to *
* the extent permitted by applicable law. You can redistribute it *
* and/or modify it under the terms of the Do What The Fuck You Want *
* To Public License, Version 2, as published by Sam Hocevar. See *
* the COPYING file or http://www.wtfpl.net/ for more details. *
*********************************************************************/
#ifndef BFS_BFTW_H
#define BFS_BFTW_H
#include <stddef.h>
#include <sys/stat.h>
/**
* Possible file types.
*/
enum bftw_typeflag {
/** Unknown type. */
BFTW_UNKNOWN,
/** Block device. */
BFTW_BLK,
/** Character device. */
BFTW_CHR,
/** Directory. */
BFTW_DIR,
/** Solaris door. */
BFTW_DOOR,
/** Pipe. */
BFTW_FIFO,
/** Symbolic link. */
BFTW_LNK,
/** Solaris event port. */
BFTW_PORT,
/** Regular file. */
BFTW_REG,
/** Socket. */
BFTW_SOCK,
/** BSD whiteout. */
BFTW_WHT,
/** An error occurred for this file. */
BFTW_ERROR,
};
/**
* Possible visit occurrences.
*/
enum bftw_visit {
/** Pre-order visit. */
BFTW_PRE,
/** Post-order visit. */
BFTW_POST,
};
/**
* Data about the current file for the bftw() callback.
*/
struct BFTW {
/** The path to the file. */
const char *path;
/** The string offset of the filename. */
size_t nameoff;
/** The depth of this file in the traversal. */
size_t depth;
/** Which visit this is. */
enum bftw_visit visit;
/** The file type. */
enum bftw_typeflag typeflag;
/** The errno that occurred, if typeflag == BFTW_ERROR. */
int error;
/** A stat() buffer; may be NULL if no stat() call was needed. */
const struct stat *statbuf;
/** A parent file descriptor for the *at() family of calls. */
int at_fd;
/** The path relative to atfd for the *at() family of calls. */
const char *at_path;
/** Appropriate flags (such as AT_SYMLINK_NOFOLLOW) for the *at() family of calls. */
int at_flags;
};
enum bftw_action {
/** Keep walking. */
BFTW_CONTINUE,
/** Skip this path's siblings. */
BFTW_SKIP_SIBLINGS,
/** Skip this path's children. */
BFTW_SKIP_SUBTREE,
/** Stop walking. */
BFTW_STOP,
};
/**
* Callback function type for bftw().
*
* @param ftwbuf
* Data about the current file.
* @param ptr
* The pointer passed to bftw().
* @return
* An action value.
*/
typedef enum bftw_action bftw_fn(struct BFTW *ftwbuf, void *ptr);
/**
* Flags that control bftw() behavior.
*/
enum bftw_flags {
/** stat() each encountered file. */
BFTW_STAT = 1 << 0,
/** Attempt to recover from encountered errors. */
BFTW_RECOVER = 1 << 1,
/** Visit directories in post-order as well as pre-order. */
BFTW_DEPTH = 1 << 2,
/** If the initial path is a symbolic link, follow it. */
BFTW_COMFOLLOW = 1 << 3,
/** Follow all symbolic links. */
BFTW_LOGICAL = 1 << 4,
/** Detect directory cycles. */
BFTW_DETECT_CYCLES = 1 << 5,
/** Stay on the same filesystem. */
BFTW_XDEV = 1 << 6,
};
/**
* Breadth First Tree Walk (or Better File Tree Walk).
*
* Like ftw(3) and nftw(3), this function walks a directory tree recursively,
* and invokes a callback for each path it encounters. However, bftw() operates
* breadth-first.
*
* @param path
* The starting path.
* @param fn
* The callback to invoke.
* @param nopenfd
* The maximum number of file descriptors to keep open.
* @param flags
* Flags that control bftw() behavior.
* @param ptr
* A generic pointer which is passed to fn().
* @return
* 0 on success, or -1 on failure.
*/
int bftw(const char *path, bftw_fn *fn, int nopenfd, enum bftw_flags flags, void *ptr);
#endif // BFS_BFTW_H
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