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FTW(3)		       FreeBSD Library Functions Manual			FTW(3)

NAME
     ftw, nftw -- traverse (walk) a file tree

SYNOPSIS
     #include <ftw.h>

     int
     ftw(const char *path, int (*fn)(const char	*, const struct	stat *,	int),
	 int maxfds);

     int
     nftw(const	char *path,
	 int (*fn)((const char *, const	struct stat *, int, struct FTW *),
	 int maxfds, int flags);

DESCRIPTION
     The ftw() and nftw() functions traverse (walk) the	directory hierarchy
     rooted in path.  For each object in the hierarchy,	these functions	call
     the function pointed to by	fn.  The ftw() function	passes this function a
     pointer to	a NUL-terminated string	containing the name of the object, a
     pointer to	a stat structure corresponding to the object, and an integer
     flag.  The	nftw() function	passes the aforementioned arguments plus a
     pointer to	a FTW structure	as defined by <ftw.h> (shown below):

     struct FTW	{
	 int base;   /*	offset of basename into	pathname */
	 int level;  /*	directory depth	relative to starting point */
     };

     Possible values for the flag passed to fn are:

     FTW_F    A	regular	file.

     FTW_D    A	directory being	visited	in pre-order.

     FTW_DNR  A	directory which	cannot be read.	 The directory will not	be
	      descended	into.

     FTW_DP   A	directory being	visited	in post-order (nftw() only).

     FTW_NS   A	file for which no stat(2) information was available.  The con-
	      tents of the stat	structure are undefined.

     FTW_SL   A	symbolic link.

     FTW_SLN  A	symbolic link with a non-existent target (nftw() only).

     The ftw() function	traverses the tree in pre-order.  That is, it pro-
     cesses the	directory before the directory's contents.

     The maxfds	argument specifies the maximum number of file descriptors to
     keep open while traversing	the tree.  It has no effect in this implemen-
     tation.

     The nftw()	function has an	additional flags argument with the following
     possible values:

     FTW_PHYS	Physical walk, do not follow symbolic links.

     FTW_MOUNT	The walk will not cross	a mount	point.

     FTW_DEPTH	Process	directories in post-order.  Contents of	a directory
		are visited before the directory itself.  By default, nftw()
		traverses the tree in pre-order.

     FTW_CHDIR	Change to a directory before reading it.  By default, nftw()
		will change its	starting directory.  The current working
		directory will be restored to its original value before	nftw()
		returns.

RETURN VALUES
     If	the tree was traversed successfully, the ftw() and nftw() functions
     return 0.	If the function	pointed	to by fn returns a non-zero value,
     ftw() and nftw() will stop	processing the tree and	return the value from
     fn.  Both functions return	-1 if an error is detected.

ERRORS
     The ftw() and nftw() functions may	fail and set errno for any of the
     errors specified for the library functions	close(2), open(2), stat(2),
     malloc(3),	opendir(3) and readdir(3).  If the FTW_CHDIR flag is set, the
     nftw() function may fail and set errno for	any of the errors specified
     for chdir(2).  In addition, either	function may fail and set errno	as
     follows:

     [EINVAL]		The maxfds argument is less than 1.

SEE ALSO
     chdir(2), close(2), open(2), stat(2), fts(3), malloc(3), opendir(3),
     readdir(3)

STANDARDS
     The ftw() and nftw() functions conform to IEEE Std	1003.1-2001
     (``POSIX.1'').

HISTORY
     These functions first appeared in AT&T System V Release 3 UNIX.  Their
     first FreeBSD appearance was in FreeBSD 5.3.

BUGS
     The maxfds	argument is currently ignored.

FreeBSD	10.1			 July 5, 2004			  FreeBSD 10.1

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUES | ERRORS | SEE ALSO | STANDARDS | HISTORY | BUGS

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