[Boost-users] Re: boost::filesystem problems

From: Martin (adrianm_at_[hidden])
Date: 2004-08-18 05:12:36

> 
> A few months ago I started to write my first multi-platform application.
> In the hope to be shielded from all kinds of filesystem specific issues,
> I started to use boost - also for the first time - mainly because of
> of boost::filesystem.

Interesting to hear from someone who is actually using the boost::filesystem 
for multi-platform.

Personally I have never really understod the reasoning behind 
the "portability" philosophy behind boost::filesystem.

Portability for me means that the code will compile and work the same on 
different platforms. Strangly enough boost::filesystem works activly against 
this by enforcing that you use "portable" filenames (unless you specificly 
turn it off).

For me, filenames are input to the application, not a result of it! Why would 
I want to force a windows user to only enter filenames that are portable?
>From a user perspective native_file_string() is portable while string() isn't 
since it doesn't present the path in a way that the user recognize.

Same thing with wide-character filenames. Why should boost::filesystem::path 
care if the path it carries is in a std::string or std::wstring? The wide-
character filesystem operations can be difficult/impossible to implement on 
some systems but so are probably other operations. The alternative today is to 
not use boost::filesystem at all.

Don't get me wrong here. I use boost::filesystem in all my applications and I 
am really happy with it but I also struggle with its limitations. Without wide-
character support I probably have to stop using it in a not to distant future.

> However - I have found that it doesn't shield me from a LOT of filesystem
> specific things.  In the meantime I was in the need of writing six additional
> functions that are filesystem specific:
> 
> std::string native_file_string(fs::path const&);
> void copy_file(fs::path const& source_file, fs::path const& target_file);
> void chmod(fs::path const& filename, bool readonly);
> bool is_readonly(fs::path const& filename);
> void rename_file(fs::path const& source_file, fs::path const& target_file);
> size_t get_file_size(fs::path const& filename);

Add to that the possibility to only iterate over specific files like "*.txt".
Only the filsystem knows if "file.TXT" matches "*.txt" so the 
directory_iterator can't be used for this simple case