term% cat index.txt FTW(3) Library Functions Manual FTW(3)
NAME
ftw - file tree walk
SYNOPSIS
#include <ftw.h>
int ftw(path, fn, depth)
char *path;
int (*fn) ( );
int depth;
#include <sys/types.h>
#include <sys/stat.h>
fn(name, statb, code) char *name; struct stat statb;
DESCRIPTION
Ftw recursively descends the directory hierarchy rooted in path. For
each object in the hierarchy, ftw calls fn, passing it a pointer to a
null-terminated character string containing the name of the object, a
pointer to a stat structure (see stat(2)) containing information about
the object, and an integer. Possible values of the integer, defined in
<ftw.h>, are FTW_F for a file, FTW_D for a directory, FTW_DNR for a di‐
rectory that cannot be read, and FTW_NS for an object on which stat
failed. If the integer is FTW_DNR, descendents of that directory will
not be processed. If the integer is FTW_NS, the stat structure will
contain garbage.
Ftw visits a directory before visiting any of its descendents.
The tree traversal continues until the tree is exhausted, an invocation
of fn returns a nonzero value, or some error is detected within ftw
(such as an I/O error). If the tree is exhausted, ftw returns zero.
If fn returns a nonzero value, ftw stops its tree traversal and returns
whatever value was returned by fn. If ftw detects an error, it returns
-1, and indicates the error type in errno.
Ftw uses one file descriptor for each level in the tree. The depth ar‐
gument limits the number of file descriptors so used. If depth is zero
or negative, the effect is the same as if it were 1. Depth must not be
greater than the number of file descriptors currently available for
use. Ftw will run more quickly if depth is at least as large as the
number of levels in the tree.
BUGS
Ftw doesn't recognize symbolic links, which can cause infinite recur‐
sion.
FTW(3)