The AmigaOS file protection bits allows for Read, Write, eXecute, Delete permissions on files, similarly to Unix (save for the Delete permission). Additional bits are Archive (reset when a file is written), Pure (signals that the program code is reentrant, thus it can be kept in memory to reduce disk swapping via the
RESIDENT command), Script (file is a shell script that can be run without using the
There's also an H bit that however has two different historically accounted interpretations for its meaning.
The first interpretation is that it means Hidden; supposedly its effect is to hide the file in a directory listing issued in the shell; the idea was that it would be applied to
#?.info files (Workbench icon files) since they're uninteresting for the user. However, this looks unimplemented as neither the
DIR nor the
LIST command have options to optionally "unhide" hidden files.
The second interpretation is that it means Hold. Supposedly an executable that is both Pure and Hold would automatically become resident after the first time it is executed.
Which of the two interpretations is correct?