---
name: "ftw.h"
section: "0p"
platform: "linux"
package: "man-pages"
version: "6.19-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/ftw.h"
---

# ftw.h(0p)

file tree traversal

## PROLOG

This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.

## NAME

ftw.h — file tree traversal

## SYNOPSIS

```
#include <ftw.h>
```

## DESCRIPTION

The *\<ftw.h\>* header shall define the **FTW** structure, which shall include at least the following members:

```
int  base
int  level
```

The *\<ftw.h\>* header shall define the following symbolic constants for use as values of the third argument to the application-supplied function that is passed as the second argument to *ftw*() and *nftw*():

- FTW\_F

  Non-directory file.

- FTW\_D

  Directory.

- FTW\_DNR

  Directory without read permission.

- FTW\_DP

  Directory with subdirectories visited.

- FTW\_NS

  Unknown type; *stat*() failed.

- FTW\_SL

  Symbolic link.

- FTW\_SLN

  Symbolic link that names a nonexistent file.

The *\<ftw.h\>* header shall define the following symbolic constants for use as values of the fourth argument to *nftw*():

- FTW\_PHYS

  Physical walk, does not follow symbolic links. Otherwise, *nftw*() follows links but does not walk down any path that crosses itself.

- FTW\_MOUNT

  The walk does not cross a mount point.

- FTW\_DEPTH

  All subdirectories are visited before the directory itself.

- FTW\_CHDIR

  The walk changes to each directory before reading it.

The following shall be declared as functions and may also be defined as macros. Function prototypes shall be provided.

```
int ftw(const char *, int (*)(const char *, const struct stat *,
    int), int);
int nftw(const char *, int (*)(const char *, const struct stat *,
    int, struct FTW *), int, int);
```

The *\<ftw.h\>* header shall define the **stat** structure and the symbolic names for *st\_mode* and the file type test macros as described in *\<sys/stat.h\>*.

Inclusion of the *\<ftw.h\>* header may also make visible all symbols from *\<sys/stat.h\>*.

*The following sections are informative.*

## APPLICATION USAGE

None.

## RATIONALE

None.

## FUTURE DIRECTIONS

None.

## SEE ALSO

***\<sys\_stat.h\>***

The System Interfaces volume of POSIX.1‐2017, *ftw()*, *nftw()*

## COPYRIGHT

Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .

Any typographical or formatting errors that appear in this page are most likely to have been introduced during the conversion of the source files to man page format. To report such errors, see https://www.kernel.org/doc/man-pages/reporting\_bugs.html .