Macintosh Hidden Files

Summary: What you should know about those hidden files and folders, which appear in MacDisk but not on a Macintosh computer.

Hidden Files and Filenames With a Leading Dot

As everybody knows, Mac OS X finds its roots in the Unix world, where there is a convention not to display filenames with a leading dot. It was therefore logical to follow this tradition.

Apple and Little Thumbling

This would need no comments if Apple had not pushed the limits a little too far. Mac OS X creates files and folders with a leading dot not only on "its" disks (disks formatted with the HFS or HFS+ formatting scheme, that is disks formatted with 16bit and 32bit data structures), but also on FAT16 or FAT32 disks (so-called PC-disks) which happen to be mounted, even once, on a Macintosh computer.
Apple, like Little Thumbling, leaves stones to find its way, even on disks which are not their property. More, on could ask whether Apple, even in the case of the HFS and HFS+ disks, really "owns" the disks and is allowed to do anything they like on "our" disks.
This should at least be an option.
See in particular Hostile Fork for some solutions.

Apple Single and Apple Double Files

Apple created two new standards called Apple Single and Apple Double to store both file forks on any magnetic medium. Apple Single files can't be recognized as such from the outside. Apple Double files are stored in two files. The "normal" file is the one which gets displayed in the Finder. It contains the data fork. The "other" file contains the resource forks and some metadata. The name is the same, but with '._' prepended. As the filename has a leading dot, it is not displayed normally.
On could call this a legitimate use of the leading dot feature.

Can One Delete Those Files/Folders?

You may want to delete those files, on a PC medium or even on a Macintosh medium. If the file begins with '._', caution, this is a resource fork file and you may need it (it could be a font, for instance). All others can be safely deleted, according to our experience.

Is It Possible to Display Hidden Files on a Mac?

A quick search on the internet gives a command line (to be entered in the Terminal application):
defaults write AppleShowAllFiles TRUE
killall Finder
To restore the default behavior :
defaults write AppleShowAllFiles FALSE
killall Finder

Pierre Duhem (ex-Logiciels & Services Duhem)
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