Detache 37.7

                     Copyright © 1992 Sebastiano Vigna

Detache is a very small and simple 2.04-only utility that will detache a
file from the file system. Note that this is completely different than
deleting a file: in particular, Detache works even if the file system did
not restart properly because of a failed validation. This happens rather
frequently if the Amiga crashes during a write on a hard disk partition: you
get the dreaded "checksum error on block xxx" requester, and your hard disk
is dead (no writes). Detache was written for people who don't like detaching
manually files with DiskEd: if you know the name of the guilty file (the
file the faulty block belongs to) you can simply detache it, and the file
system will be happy to restart.

The parameters of Detache are

NAME/A,FORCE/S,VALIDATE/S

where NAME is the name of the file (or directory) that you want to detache
(detaching a directory will detache everything contained in it!). FORCE
forces Detache to skip the check for the existence of the NAME file/dir.
This means that whatever is occupying the place (i.e., the hash table
position) of that file/dir will be detached. Be very careful when specifying
FORCE. VALIDATE will force the file system to validate the volume. This will
happen automatically if you're detaching something on a non-validated
partition, but the switch is there for maximum flexibility: in fact, the
blocks of a detached file do NOT get back to the file system until the next
validation.

Detache works by finding out where the given file (or directory) lives, and
by resetting the pointers of the DOS hash chains in such a way that the file
header block is skipped. This process is of course rather dangerous, since
it implies an Exec device level write on your hard disk. Detache has
redundant internal checks, so it should never do any harm. In any case, it
prints whatever is doing, so you can guess what happened.

Detache understands the issues of non-512-bytes-block devices and of
internationalized file systems, so it should work under any of the current
versions of the OFS/FFS.

Detache is Copyright © 1992 Sebastiano Vigna and it's freely distributable
as long as all of its files are included in their original form without
additions, deletions, or modifications of any kind, and only a nominal fee
is charged for its distribution. This software is provided "AS IS" without
warranty of any kind, either expressed or implied. By using Detache, you
agree to accept the entire risk as to the quality and performance of the
program.

Comments, complaints, desiderata are welcome.


         Sebastiano Vigna
         Via California 22
         I-20144 Milano MI

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