The Macintosh OS uses an 8 bit charactrer set for file
names and disallows only the character colon (":")
Actually, the colon is reserved for use as a separator. Full path
specifications would employ it.
a typical unix partial path sa:
/usr/spool/xyz/neXXfoo
becomes
:usr:spool:xyz:neXXfoo
implying the current context,
or
big disk:usr:spool:xyz:neXXfoo
for a complete path on a volume named "big disk". Note that imbedded blanks are
quite legal.
::
Is meaningless except in partial pathnames, where it backs up one level of
parent.
Apple Human Interface guidelines strongly discourage exposing users to
full/partial path specification, on the premise that a user should never have to
type one, only very rare programs employ full path names at all (typically
development/maintenance tools). The majority of programs determine file paths
via a system supported GUI called StandardFile, which displays a list of all
files of the curent subdirectory, and a list of the parents of that directory.
Feedback to the program is a structure specifing the file path in terms of its
volume id, parent directory id, and filename.
Also, filenames are currently allowed to be 31 characters long, while
folder/volume names are restricted to 27. It is a good idea for full path names
to resolve to less than 256 chars, as internal system structures take partial
pathnames as a pascal string (for historical reasons), but it is rare for anyone
to get bitten by this.
end of lecture.
--
dana s emery <de19(_at_)umail(_dot_)umd(_dot_)edu>