9.3 The File

This is the last stop on our quick UNC tour of SMB.

Files, like directories, should be fairly familiar and fairly straightforward. As has been continually demonstrated, however, things in the CIFS world are not always as simple as they ought to be. Our point of interest on this part of the tour is the distinction between server filesystem syntax and semantics and client expectations... a very gnarled knot for CIFS implementors.

Consider, for example, a bunch of Windows clients connecting to an SMB server running on Linux. On the Linux system the filenames Corgi , corgi , and CORGI would all be distinct because Linux filesystems are typically case-sensitive. Windows, however, expects filenames to be case-insensitive, so all three names are the same from the Windows point of view. Thus, we have a conflict. How does a Linux server make all three files available to the Windows client?

Other difficult issues include:

• filename lengths,

• valid characters ,

• file access permissions, and

• the end-of-line delimiter in text files.

These are complex problems, not easily solved . The CIFS protocol suite is not designed to be agnostic with regard to such things. In fact, CIFS goes out of its way at times to support features that are specific to DOS, OS/2, and Windows.

...and that concludes our tour. It's time to visit the gift shoppe.