ftw.c

Axis 221 camera embedded programing interface

	else
	    flag = FTW_F;
    }

    if (result == 0
	    && (flag == FTW_NS
		|| !(data->flags & FTW_MOUNT) || st.st_dev == data->dev))
    {
	if (flag == FTW_D)
	{
	    if ((data->flags & FTW_PHYS)
		    || (!find_object (data, &st)
			/* Remember the object.  */
			&& (result = add_object (data, &st)) == 0))
	    {
		result = ftw_dir (data, &st);

		if (result == 0 && (data->flags & FTW_CHDIR))
		{
		    /* Change back to the parent directory.  */
		    int done = 0;
		    if (dir->stream != NULL)
			if (fchdir (dirfd (dir->stream)) == 0)
			    done = 1;

		    if (!done)
		    {
			if (data->ftw.base == 1)
			{
			    if (chdir ("/") < 0)
				result = -1;
			}
			else
			    if (chdir ("..") < 0)
				result = -1;
		    }
		}
	    }
	}
	else
	    result = (*data->func) (data->dirbuf, &st, data->cvt_arr[flag],
		    &data->ftw);
    }

    return result;
}

static int
internal_function
ftw_dir (struct ftw_data *data, struct STAT *st)
{
    struct dir_data dir;
    struct dirent *d;
    int previous_base = data->ftw.base;
    int result;
    char *startp;

    /* Open the stream for this directory.  This might require that
       another stream has to be closed.  */
    result = open_dir_stream (data, &dir);
    if (result != 0)
    {
	if (errno == EACCES)
	    /* We cannot read the directory.  Signal this with a special flag.  */
	    result = (*data->func) (data->dirbuf, st, FTW_DNR, &data->ftw);

	return result;
    }

    /* First, report the directory (if not depth-first).  */
    if (!(data->flags & FTW_DEPTH))
    {
	result = (*data->func) (data->dirbuf, st, FTW_D, &data->ftw);
	if (result != 0)
	    return result;
    }

    /* If necessary, change to this directory.  */
    if (data->flags & FTW_CHDIR)
    {
	if (fchdir (dirfd (dir.stream)) < 0)
	{
	    int save_err = errno;
	    closedir (dir.stream);
	    __set_errno (save_err);

	    if (data->actdir-- == 0)
		data->actdir = data->maxdir - 1;
	    data->dirstreams[data->actdir] = NULL;

	    return -1;
	}
    }

    /* Next, update the `struct FTW' information.  */
    ++data->ftw.level;
    startp = strchr (data->dirbuf, '\0');
    /* There always must be a directory name.  */
    assert (startp != data->dirbuf);
    if (startp[-1] != '/')
	*startp++ = '/';
    data->ftw.base = startp - data->dirbuf;

    while (dir.stream != NULL && (d = readdir (dir.stream)) != NULL)
    {
	result = process_entry (data, &dir, d->d_name, _D_EXACT_NAMLEN (d));
	if (result != 0)
	    break;
    }

    if (dir.stream != NULL)
    {
	/* The stream is still open.  I.e., we did not need more
	   descriptors.  Simply close the stream now.  */
	int save_err = errno;

	assert (dir.content == NULL);

	closedir (dir.stream);
	__set_errno (save_err);

	if (data->actdir-- == 0)
	    data->actdir = data->maxdir - 1;
	data->dirstreams[data->actdir] = NULL;
    }
    else
    {
	int save_err;
	char *runp = dir.content;

	while (result == 0 && *runp != '\0')
	{
	    char *endp = strchr (runp, '\0');

	    result = process_entry (data, &dir, runp, endp - runp);

	    runp = endp + 1;
	}

	save_err = errno;
	free (dir.content);
	__set_errno (save_err);
    }

    /* Prepare the return, revert the `struct FTW' information.  */
    data->dirbuf[data->ftw.base - 1] = '\0';
    --data->ftw.level;
    data->ftw.base = previous_base;

    /* Finally, if we process depth-first report the directory.  */
    if (result == 0 && (data->flags & FTW_DEPTH))
	result = (*data->func) (data->dirbuf, st, FTW_DP, &data->ftw);

    return result;
}


static int
internal_function
ftw_startup (const char *dir, int is_nftw, void *func, int descriptors, int flags)
{
    struct ftw_data data;
    struct STAT st;
    int result = 0;
    int save_err;
    char *cwd = NULL;
    char *cp;

    /* First make sure the parameters are reasonable.  */
    if (unlikely(dir==NULL || *dir=='\0')) {
	__set_errno (ENOENT);
	return -1;
    }
    if ((strlen(dir)+1) > NAME_MAX) {
	__set_errno(ENAMETOOLONG);
	return -1;
    }

    data.maxdir = descriptors < 1 ? 1 : descriptors;
    data.actdir = 0;
    data.dirstreams = (struct dir_data **) alloca (data.maxdir
	    * sizeof (struct dir_data *));
    memset (data.dirstreams, '\0', data.maxdir * sizeof (struct dir_data *));

    /* PATH_MAX is always defined when we get here.  */
    data.dirbufsize = MAX (2 * strlen (dir), PATH_MAX);
    data.dirbuf = (char *) malloc (data.dirbufsize);
    if (data.dirbuf == NULL)
	return -1;
    cp = stpcpy (data.dirbuf, dir);
    /* Strip trailing slashes.  */
    while (cp > data.dirbuf + 1 && cp[-1] == '/')
	--cp;
    *cp = '\0';

    data.ftw.level = 0;

    /* Find basename.  */
    while (cp > data.dirbuf && cp[-1] != '/')
	--cp;
    data.ftw.base = cp - data.dirbuf;

    data.flags = flags;

    /* This assignment might seem to be strange but it is what we want.
       The trick is that the first three arguments to the `ftw' and
       `nftw' callback functions are equal.  Therefore we can call in
       every case the callback using the format of the `nftw' version
       and get the correct result since the stack layout for a function
       call in C allows this.  */
    data.func = (NFTW_FUNC_T) func;

    /* Since we internally use the complete set of FTW_* values we need
       to reduce the value range before calling a `ftw' callback.  */
    data.cvt_arr = is_nftw ? nftw_arr : ftw_arr;

    /* No object known so far.  */
    data.known_objects = NULL;

    /* Now go to the directory containing the initial file/directory.  */
    if (flags & FTW_CHDIR)
    {
	/* GNU extension ahead.  */
	cwd =  getcwd (NULL, 0);
	if (cwd == NULL)
	    result = -1;
	else if (data.ftw.base > 0)
	{
	    /* Change to the directory the file is in.  In data.dirbuf
	       we have a writable copy of the file name.  Just NUL
	       terminate it for now and change the directory.  */
	    if (data.ftw.base == 1)
		/* I.e., the file is in the root directory.  */
		result = chdir ("/");
	    else
	    {
		char ch = data.dirbuf[data.ftw.base - 1];
		data.dirbuf[data.ftw.base - 1] = '\0';
		result = chdir (data.dirbuf);
		data.dirbuf[data.ftw.base - 1] = ch;
	    }
	}
    }

    /* Get stat info for start directory.  */
    if (result == 0)
    {
	const char *name = ((data.flags & FTW_CHDIR)
		? data.dirbuf + data.ftw.base
		: data.dirbuf);

	if (((flags & FTW_PHYS)
		    ? LSTAT (name, &st)
		    : XSTAT (name, &st)) < 0)
	{
	    if (!(flags & FTW_PHYS)
		    && errno == ENOENT
		    && LSTAT (name, &st) == 0
		    && S_ISLNK (st.st_mode))
		result = (*data.func) (data.dirbuf, &st, data.cvt_arr[FTW_SLN],
			&data.ftw);
	    else
		/* No need to call the callback since we cannot say anything
		   about the object.  */
		result = -1;
	}
	else
	{
	    if (S_ISDIR (st.st_mode))
	    {
		/* Remember the device of the initial directory in case
		   FTW_MOUNT is given.  */
		data.dev = st.st_dev;

		/* We know this directory now.  */
		if (!(flags & FTW_PHYS))
		    result = add_object (&data, &st);

		if (result == 0)
		    result = ftw_dir (&data, &st);
	    }
	    else
	    {
		int flag = S_ISLNK (st.st_mode) ? FTW_SL : FTW_F;

		result = (*data.func) (data.dirbuf, &st, data.cvt_arr[flag],
			&data.ftw);
	    }
	}
    }

    /* Return to the start directory (if necessary).  */
    if (cwd != NULL)
    {
	int save_err = errno;
	chdir (cwd);
	free (cwd);
	__set_errno (save_err);
    }

    /* Free all memory.  */
    save_err = errno;
    tdestroy (data.known_objects, free);
    free (data.dirbuf);
    __set_errno (save_err);

    return result;
}



/* Entry points.  */

int FTW_NAME (const char *path, FTW_FUNC_T func, int descriptors)
{
    return ftw_startup (path, 0, func, descriptors, 0);
}

int NFTW_NAME (const char *path, NFTW_FUNC_T func, int descriptors, int flags)
{
    return ftw_startup (path, 1, func, descriptors, flags);
}
#endif