You can also use pv as you would use cat, e.g. pv file.tar.gz.part1 file.tar.gz....

You can also use pv as you would use cat, e.g.

    pv file.tar.gz.part1 file.tar.gz.part2 | tar -x -z

Just like cat, pv used this way will stream out the concatenation of the passed-in file paths; but it will also add up the sizes of these files and use them to calculate the total stream size, i.e. the divisor for its displayed progress percentage.