9.6.3 Concatenate Volumes into a Single Archive

Sometimes it is necessary to convert existing GNU tar multi-volume archive to a single tar archive. Simply concatenating all volumes into one will not work, since each volume carries an additional information at the beginning. GNU tar is shipped with the shell script tarcat designed for this purpose.

The script takes a list of files comprising a multi-volume archive and creates the resulting archive at the standard output. For example:

     tarcat vol.1 vol.2 vol.3 | tar tf -

The script implements a simple heuristics to determine the format of the first volume file and to decide how to process the rest of the files. However, it makes no attempt to verify whether the files are given in order or even if they are valid tar archives. It uses dd and does not filter its standard error, so you will usually see lots of spurious messages.