IT Services Guides
File Naming Issues
For Mac and PC users
Authors: David Riddle, Duncan Branley.Version 1.4, February 2007
Introduction
Normally, you do not need to worry about how you name your computer files - you can just accept what your programs offers. But there are two circumstances in which problems can sometimes occur in connection with file naming:
- If you need to share files between a PC an a Mac
- If you are copying PC files to CD-ROM
Goldsmiths has PCs running Windows and Apple Macs running OS-9 or OS-X throughout the College. Sometimes it is necessary to share files with a user with a different system on removable media (CD, USB flash drive, memory card, etc.) or using a network drive (e.g. J: or K:). It can also be an issue when sending files by e-mail as attachments, as you may not know what type of computer your recipient uses.
In particular, staff PC users in College need to be aware of the issues because they affect files submitted via the K: drive to the Reprographic Unit, which uses Macintosh systems.
Also, sometimes you may need to work on the other platform yourself (e.g. using the Mac_Files folder on your N: drive under Macintosh OS-9), so this doesn't only apply to sharing files with other users.
There are two aspects of file naming where problems may occur, and the sections below offer simple guidelines on how to avoid potential problems.
File extensions
Computer filenames have two parts: the main name and what is called a file extension , which serves to identify what sort of file it is. The extension usually has 3 letters (sometimes 2 or 4), and is separated from the main part of the file name by a full stop. Some file extensions are generic, others are associated with particular commercial software packages - for example .txt is a generic file extension for any plain text file, while .ppt is specifically used by Microsoft PowerPoint. Generic file types can be viewed and edited with many different programs.
Under both Windows and Macintosh operating systems, having the correct file extension means that double-clicking on the file will open the appropriate program with the file. If you are creating material for the web, correct file extensions are needed ensure that a web browser will handle them correctly.
What you need to do
Mac users:
If you are using OS-9, you need to ensure that a file extension is added to the name of every file you create. If you fail to do this, not only will a PC user be unable to open it with the correct program, anyone using Macintosh OS-X will have the same problem. Under OS-X, the appropriate file extension is added automatically.
PC users:
The correct extension is normally added by default when program saves a file on a PC, so you should not need to take any action. A Mac should be able to open such files with the correct program.
File Name Length
The main part of a filename (the bit before the full stop) can also be created by default by some programs and on PCs this sometimes results in a very long filename. This can cause problems for Mac users since the Mac has a limit of 31 characters for file names. You need to ensure that the main part of the filename is no longer than 25 characters - including spaces. As discussed above, when a file extension is added automatically this adds another four characters to the filename (e.g. .doc).
If you are writing files to CD-ROM on a PC and have some very long file names, you may encounter problems. Ideally, the software you are using should warn you of the problem and offer to truncate the file name automatically, but it may simply not copy the file. Also, automatic filename truncation may not be helpful, if your file needs a particular name for some reason, e.g. it's part of a Web site.
What you need to do
Mac users:
If a PC file is given a name with more than 31 characters in total, OS-X users should have no problem, but a Mac OS-9 user will not be able to see the file on their computer and so won't be able to open or work with it. If you cannot see a file which someone assures you they have copied or sent to you as an e-mail attachment please check the filename length with them before calling the Computer Help Desk.
PC Users:
Make sure you don't create files with names longer than 26 characters, including spaces. This means that when an extension it will still fall withing the Mac's 31-character limit.
Common file extensions
File extensions for programs commonly used in College include:
| Extension | File Type |
|---|---|
| Proprietary | |
| .doc | Microsoft Word document |
| .xls | Microsoft Excel spreadsheet |
| .ppt | Micrsosoft PowerPoint presentation |
| .pps | Micrsosoft PowerPoint slideshow |
| .cwk | Claris Works document |
| .enl | EndNote library |
| .psd | Photoshop file |
| .qxd | QuarkXPress document |
| Adobe Acrobat documents | |
| .ps | PostScript File (for printing) |
| Generic | |
| .txt | plain text file |
| .rtf | rich text format (for word-processor) |
| .csv | comma separated values (for spreadsheet) |
| .gif .jpg, .jpeg |
common graphics file formats |
| .htm .html |
Web pages |
There are many comprehensive lists of standard file extensions available on-line, including: