ugh.book

UFS: The Root of All Evil 275

Recall that Unix does place one hard-and-fast restriction on filenames: they
may never, ever contain the magic slash character (/), since the Unix kernel
uses the slash to denote subdirectories. To enforce this requirement, the
Unix kernel simply will never let you create a filename that has a slash in
it. (However, you can have a filename with the 0200 bit set, which does list
on some versions of Unix as a slash character.)

Never? Well, hardly ever.

Date: Mon, 8 Jan 90 18:41:57 PST

From: [email protected] (Steve Sekiguchi)

Subject: Info-Mac Digest V8 #3^5

I’ve got a rather difficult problem here. We've got a Gator Box run-

ning the NFS/AFP conversion. We use this to hook up Macs and

Suns. With the Sun as a AppleShare File server. All of this works

great!

Now here is the problem, Macs are allowed to create files on the Sun/

Unix fileserver with a “/” in the filename. This is great until you try

to restore one of these files from your “dump” tapes. “restore” core

dumps when it runs into a file with a “/” in the filename. As far as I

can tell the “dump” tape is fine.

Does anyone have a suggestion for getting the files off the backup

tape?

Thanks in Advance,

Steven Sekiguchi Wind River Systems

sun!wrs!steve, [email protected] Emeryville CA, 94608

Apparently Sun’s circa 1990 NFS server (which runs inside the kernel)
assumed that an NFS client would never, ever send a filename that had a
slash inside it and thus didn’t bother to check for the illegal character.
We’re surprised that the files got written to the dump tape at all. (Then
again, perhaps they didn’t. There’s really no way to tell for sure, is there
now?)

(^5) Forwarded to UNIX-HATERS by Steve Strassmann.