02-15-2005
Unix doesn't support the notion of a hidden file. Even having a leading dot only hides the file from people who prefer to not see it. Almost everyone knows about "ls -a" and so on. Seeing a filename depends on reading the directory that contains it. So making a directory unreadable will "hide" all of the files it contains. There are a very few funky tricks to render files "hidden". Here is one...
One sure way to hide a file is to ensure that it has no filenames. A program can create a file, and then unlink it. No other program can now open the file. But the file will not disappear until every program that has it open closes it, perhaps by exiting. This happens a lot and it's probably the number one way that junior admins accidentally hide files from themselves. A filesystem will fill up and the admin will see a very large file called, say, huge.log. At this point he will do a "rm huge.log". But if a program still has that log file open, the space will not be freed. Until the program closes the file or exits, the space is still used. I suppose that we can call that file "hidden".
The other techniques all require root and cannot be generally applied. And they are not great ideas anyway so I won't mention them.
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LEARN ABOUT DEBIAN
raddepend
RADDEPEND(1) General Commands Manual RADDEPEND(1)
NAME
raddepend - find RADIANCE scene dependencies
SYNOPSIS
raddepend file ..
DESCRIPTION
Raddepend uses getbbox(1) to expand scene file arguments and find file dependencies for make(1) or rad(1). Raddepend looks only in the
current directory, so dependencies hidden elsewhere in the filesystem will not be found or named.
The output is the name of files, one per line, that were accessed during the expansion of the input file arguments. The file arguments are
excluded from the list. If no input files are given, the standard input is read.
AUTHOR
Greg Ward
BUGS
On some older NFS systems, the file access dates are not updated promptly. As a result, raddepend may not be 100% reliable on these sys-
tems. If the output seems to be missing essential files, this is no doubt why. The only fix is to put in a longer sleep time between the
getbbox call and the final ls(1).
SEE ALSO
make(1), oconv(1), rad(1), xform(1)
RADIANCE
4/15/94 RADDEPEND(1)