FTW(3) BSD Library Functions Manual FTW(3)

NAME
     ffttww,, nnffttww - traverse (walk) a file tree

SYNOPSIS
     ##iinncclluuddee <>

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

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

DESCRIPTION
     These functions are provided for compatibility with legacy code.  New     ccooddee sshhoouulldd uussee tthhee fts(33) ffuunnccttiioonnss..

     The ffttww() and nnffttww() 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 ffttww() 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 nnffttww() function passes the aforementioned arguments plus a
     pointer to a FTW structure as defined by  (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:

     FTWF    A regular file.

     FTWD    A directory being visited in pre-order.

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

     FTWDP   A directory being visited in post-order (nnffttww() only).

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

     FTWSL   A symbolic link.

     FTWSLN  A symbolic link with a non-existent target (nnffttww() only).

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

     FTWPHYS   Physical walk, don't follow symbolic links.

     FTWMOUNT  The walk will not cross a mount point.

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

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

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

EERRRROORRSS
     The ffttww() and nnffttww() 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 FTWCHDIR flag is set, the
     nnffttww() 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 or greater than
                        OPENMAX.

LLEEGGAACCYY EERRRROORRSS
     The ffttww() and nnffttww() functions are far more tolerant of symlink cycles
     and are lax in reporting errors while accessing the initial path.  When
     nnffttww() is passed FTWMOUNT it will pass the callback the mount point.

SEE ALSO
     chdir(2), close(2), open(2), stat(2), compat(5), fts(3), malloc(3),
     opendir(3), readdir(3)

STANDARDS
     The ffttww() and nnffttww() functions conform to IEEE Std 1003.1-2001
     (``POSIX.1'') and Version 3 of the Single UNIX Specification (``SUSv3'').

HISTORY     Prior to MacOS X 10.4 ffttww did not follow symlinks.

BUGS
     The maxfds argument is currently ignored.

BSD                              May 20, 2003                              BSD