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Getting Along with the Dark Side
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by John MacDonald

When we get files from or transfer files to a Wintel machine we need to understand some of the restrictions that the other side has to deal with.

Forbidden Characters

The only thing forbidden on the Mac side is the use of a period as the first character in a file name. Apple doesn't recommend doing that. It can cause problems. That is the only restriction to creating a file name on the Mac that I know of.

[Webmaster's note: Files starting with a period are hidden, but can be accessed from the Mac OS X command line. There are two types of separators: 1) The colon ":" is the classic Mac OS separator (not allowed under any version of Mac OS), and 2) Slashes "/" are Unix style directory separators, not to be used. All of the other characters forbidden under DOS can, but should not be used under Mac OS X, since they are used for command line scripting]

On the Wintel side, it is quite a bit different. The following characters cannot be used in a Windows file name.

Comma ,
Colon :
Semicolon ;
Equals sign =
Question mark ?
Slash /
Back slash \
Asterisk *
Double quote marks "
Greater than sign >
Less than sign <
Brackets [ ]
Vertical bar (pipe) |

And any characters that require the use of any modifier key, except the Shift key.


In addition to this restriction on characters that can be used, Windows machines place an extension at the end of file names so Windows or DOS can figure out what kind of files they are. When you get files from a Windows machine, they will have an extension. There are hundreds of them and many are totally incompatabile with any other programs on the Wintel machines let alone compatible with the Mac. The fist of extensions below contains a few of those that are compatible cross-platform software for Macs and Wintel machines. When you send a document to a Wintel user it is a good idea to place the extension at the end of your file and not use any of the forbidden characters in the file name. That way the recipient on the dark side will not have any problems with their machine seeing the file (there are ways around this on the PC but not many people are aware of how to see the files when they do not show up).

.ai Adobe Illustrator (I think this is for versions higher than 5.0, see il5 below)
.bmp Windows or OS/2 bitmap graphic
.cdd ClarisDraw document
.cdr CorelDraw document
.com application program
.dbf database file (various spreadsheet and database applications)
.doc Microsoft Word document
.dot Microsoft Word template (beware, this could be infected with a macro virus)
.eps Encapsulated Postscript file
.exe self-extracting Zip (compressed) file or application
.gif GIF (Graphics Interchange Format) graphic
.htm or .html Web page
.il5 Adobe Illustrator document (the number is the application version)
.jpg JPEG (Joint Photographic Experts Group) compressed graphic
.pct PICT graphic
.pcx PC Paintbrush graphic
.pdf Adobe Acrobat document
.pm6 Adobe PageMaker 6 (the number is the application version)
.ppt Microsoft PowerPoint document
.prn or .ps PostScript files
.psd Adobe Photoshop document
.pt6 Adobe PageMaker 6 template (the number is the application version)
.pub Microsoft Publisher document
.qxp QuarkXpress document
.rtf Rich Text Format word processing document (open in a word processor or place file in PageMaker)
.sam AmiPro document
.tbl Adobe Table Editor document
.txt plain text (open in a word processor or place file in PageMaker)
.wk1 Lotus 1-2-3 spreadsheet (the number is the application version)
.wks Microsoft Works document
.wmf Windows Metafile graphic
.wpd Corel WordPerfect document (version 6.1 and higher)
.wpg Corel WordPerfect graphics
.wql Quattro Pro spreadsheet (the number is the application version)
.wri Microsoft Write document
.ws2 WordStar document (the number is the application version)
.xls Microsoft Excel spreadsheet
.zip compressed file (PIMP format)
Version: 1.1.0 - 20070310
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