[boost] Filesystem iterator suggestion

From: Martin (adrianm_at_[hidden])
Date: 2004-04-26 03:22:14

I have used the filesystem library for some time now and noticed that there is 
no portable way of iterating over files in a directory that matches a pattern.

In my applications I often need to find all files in a directory that 
matches "*.txt" or "input.*".

I think it would be a good idea to add another constructor to the 
directory_iterator that support some primitive wilcards. The support could be 
limited to "*" at the end or followed by a "." 
(e.g. "*", "a*.*", "*.txt", "a.*")

for (path::directory_iterator itr = directory_iterator(path, "*.txt"); itr != 
directory_iterator(); ++itr)
  ...

I assume this limited wildcard support could easily be ported to most 
operating systems.

-------------------

Another small improvement that would make the directory_iterator easier to use 
is to somehow allow it to only list directories or files. In the current 
implementation you need to create a temporary to use an algorithm on all files 
in a directory (or use some lambda if construct).

std::vector<path> tmp;
std::remove_copy_if(directory_iterator(dir), directory_iterator(), 
back_inserter(tmp), std::ptr_fun(is_directory))
std::for_each(tmp.begin(), tmp.end(), func);

instead of just
std::for_each(directory_iterator(dir, files_only), directory_iterator(), func);