#include <ftw.h> int
Fo ftw
Fa const char *path
Fa int lp]*fnrp]lp]const char *, const struct stat *, intrp]
Fa int maxfds
Fc Ft int
Fo nftw
Fa const char *path
Fa int lp]*fnrp]lp]const char *, const struct stat *, int, struct FTW *rp]
Fa int maxfds
Fa int flags
Fc
DESCRIPTION
The
ftw ();
and
nftw ();
functions traverse (walk) the directory hierarchy rooted in
Fa path .
For each object in the hierarchy, these functions call the function
pointed to by
Fa fn .
The
ftw ();
function passes this function a pointer to a
NUL -terminated string containing
the name of the object, a pointer to a
Vt stat
structure corresponding to the
object, and an integer flag.
The
nftw ();
function passes the aforementioned arguments plus a pointer to a
Vt FTW
structure as defined by
#include <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
Fa 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
Fn ( nftw
only).
FTW_NS
A file for which no
stat(2)
information was available.
The contents of the
Vt stat
structure are undefined.
FTW_SL
A symbolic link.
FTW_SLN
A symbolic link with a non-existent target
Fn ( nftw
only).
The
ftw ();
function traverses the tree in pre-order.
That is, it processes the directory before the directory's contents.
The
Fa maxfds
argument specifies the maximum number of file descriptors
to keep open while traversing the tree.
It has no effect in this implementation.
The
nftw ();
function has an additional
Fa 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
Fa fn
returns a non-zero value,
ftw ();
and
nftw ();
will stop processing the tree and return the value from
Fa 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:
