"Darrin B. Jewell" <dbj@netbsd.org> writes:
> "Darrin B. Jewell" <dbj@netbsd.org> writes:
>> I also plan to create a simple shell script test for the existence of
>> the botched superblock problem.
>
> For reference, here's a script that will do such a test.

1) You might want to embed the magic numbers using \s and the printf
   utility, as in
 FOO=`printf "\xxx\xxx\xxx\xxx"
2) How do I run this? Just "checksb /dev/rwd0a"?

Perry


>
> --=-=-=
> Content-Type: application/x-sh
> Content-Disposition: attachment; filename=checksb.sh
> Content-Description: shell script to test for botched superblock conditions
>
> #!/bin/sh
>
> # This shell script extracts the `ffs superblock' of any files listed
> # on standard input and tests for the following condition:
> # ((fs_magic == FS_UFS1_MAGIC) || fs_magic == FS_UFS1_MAGIC_SWAPPED) &&
> # (fs_sbsize == fs_maxbsize) && !(fs_old_flags & FS_FLAGS_UPDATED)
> # it prints the names of successful tests on stdout
> #
> # dbj@netbsd.org 2004-04-12T13:49:43-0400 
>
> #debug=1
>
> fsmagicn="^@^A^YT"  # 0x00011954 FS_UFS1_MAGIC
> fsmagics="T^Y^A^@"  # 0x54190100 FS_UFS1_MAGIC_SWAPPED
>
> check_part()
> {
>   magic="`(dd if="$1" bs=8192 skip=1 count=1 | dd bs=1 count=4 skip=1372 | cat -v) 2> /dev/null`"
>   if [ "${magic}" = "${fsmagicn}" -o "${magic}" = "${fsmagics}" ]; then
>     bsize="`(dd if="$1" bs=8192 skip=1 count=1 | dd bs=1 count=4 skip=48 | cat -v) 2> /dev/null`"
>     maxbsize="`(dd if="$1" bs=8192 skip=1 count=1 | dd bs=1 count=4 skip=860 | cat -v) 2> /dev/null`"
>     oldflags="`(dd if="$1" bs=8192 skip=1 count=1 | dd bs=1 count=1 skip=211 | cat -v) 2> /dev/null`"
>     if [ ! -z "${debug}" ]; then
>       echo "$1: magic=${magic} bsize=${bsize} maxbsize=${maxbsize} oldflags=${oldflags}"
>     fi
>     if [ "${bsize}" = "${maxbsize}" ]; then
>       case "${oldflags}" in
>         M-*)
>         ;;
>  	*)
>         return 0
>         ;;
>       esac
>     fi
>   fi
>   return 1
> }
>
> for p in ${1+"$@"}; do
>   if check_part "$p"; then
>     echo "$p"
>   fi
> done
> exit 0
>
> --=-=-=--
>

-- 
Perry E. Metzger		perry@piermont.com