Ubuntu Manpage: fiz - analyze damaged zoo archive for data recovery

NAME

       fiz - analyze damaged zoo archive for data recovery

SYNOPSIS

       fiz archive[.zoo]

DESCRIPTION

Fiz is used to analyze damaged zoo archives and locate directory entries and file data in
them. The current version of fiz is 2.0 and it is meant to be used in conjunction with
zoo version 2.0. Fiz makes no assumptions about archive structure. Instead, it simply
searches the entire subject archive for tag values that mark the locations of directory
entries and file data. In a zoo archive, a directory entry contains information about a
stored file such as its name, whether compressed or not, and its timestamp. The file data
are the actual data for the archived file, and may be either the original data, or the
result of compressing the file.

For each directory entry found, fiz prints where in the archive it is located, the
directory path and filename(s) found in it, whether the directory entry appears to be
corrupted (indicated by [*CRC Error*]), and the value of the pointer to the file data that
is found in the directory entry. For each block of file data found in the archive, fiz
prints where in the archive the block begins. In the case of an undamaged archive, the
pointer to file data found in a directory entry will correspond to where fiz actually
locates the data. Here is some sample output from fiz:

****************
2526: DIR [changes] ==> 95
2587: DATA
****************
3909: DIR [copyrite] ==> 1478
3970: DATA
4769: DATA
****************

In such output, DIR indicates where fiz found a directory entry in the archive, and DATA
indicates where fiz found file data in the archive. Filenames located by fiz are enclosed
in square brackets, and the notation "==> 95" indicates that the directory entry found
by fiz at position 2526 has a file data pointer to position 95. In actuality, fiz found
file data at positions 2587, 3970, and 4769. Since fiz found only two directory entries,
and each directory entry corresponds to one file, one of the file data positions is an
artifact.

Once the locations of directory entries and file data are found, the @ modifier to zoo's
archive list and extract commands can be used and the archive contents selectively listed
or extracted, skipping the damaged portion. This is further described in the
documentation for zoo(1).

In the above case, commands to try giving to zoo might be x@2526,2587 (extract beginning
at position 2526, and get file data from position 2587), x@3090,3970 (extract at 3090, get
data from 3970) and x@3909,4769 (extract at 3909, get data from 4769). Once a correctly-
matched directory entry/file data pair is found, zoo will in most cases synchronize with
and correctly extract all files subsequently found in the archive. Trial and error should
allow all undamaged files to be extracted. Also note that self-extracting archives
created using sez (the Self-Extracting Zoo utility for MS-DOS), which are normally
executed on an MS-DOS system for extraction, can be extracted on non-MSDOS systems in a
similar way.

BUGS

       Random  byte  patterns  can  occasionally  be  incorrectly recognized as tag values.  This
       occurs very rarely, however, and trial and error will usually permit all undamaged data to
       be extracted.

DIAGNOSTICS

       Fiz always exits with a status code of 0.

FUTURE DIRECTIONS

       Automation  of  data  recovery from a damaged archive is potentially achievable.  However,
       since damaged archives occur only rarely, fiz as it currently stands is unlikely to change
       much in the near future.

AUTHOR

       Rahul Dhesi

                                           Jan 31, 1988                                    FIZ(1)