DOS/Windows Filenames

Posted on 1998-07-17
Last Modified: 2013-11-20
Is there a function to tell if a filename is invalid??  The reason I'm asking is because I am writing some code to save files and I want to check if the name is valid before I actually save it.
Question by:dlbrown051198
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Accepted Solution

psdavis earned 50 total points
ID: 1319403
You do have the _splitpath function which will take a filename and parse it into it's respective pieces.  Then you can try the _makepath function to restore it.  

You can then check both strings to make sure the before and after info is correct.  You can also validate each section (drive number, extension, etc., individually per your requirements).

There is also CFile::GetStatus( CFileStatus&) that will validate that the file exists.


void main( void ){   char path_buffer[_MAX_PATH];   char drive[_MAX_DRIVE];
   char dir[_MAX_DIR];   char fname[_MAX_FNAME];   char ext[_MAX_EXT];
   _makepath( path_buffer, "c", "\\sample\\crt\\", "makepath", "c" );
   printf( "Path created with _makepath: %s\n\n", path_buffer );
   _splitpath( path_buffer, drive, dir, fname, ext );
   printf( "Path extracted with _splitpath:\n" );
   printf( "  Drive: %s\n", drive );   printf( "  Dir: %s\n", dir );
   printf( "  Filename: %s\n", fname );   printf( "  Ext: %s\n", ext );}


Author Comment

ID: 1319404
I'm actually checking only the filename portion, not the directory path.  More specifically, my users will be allowed to use international characters and I noticed that the CFile::Open() function has no problem with them.  I'm just curious as to what Windows uses to validate characters in a filenames.

Expert Comment

ID: 1319405
For Win32 filenames, and international characters, I believe once you have the filename portion, you are relatively unrestricted except for characters such as '/' and '\'.  If you do know of a restriction, place the filename in a CString variable and do a CString::FindOneOf( "/\\" ) to look for your own defined invalid characters.



Author Comment

ID: 1319406

Expert Comment

ID: 1319407
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