I would like to get the sha1 checksums of all files inside a simple tar archive as a list.
This should be done on a busybox machine where only a minimal tar binary is avalable, see http://linux.die.net/man/1/busybox for the available commands.
Without using the disk space to unpack the big tar file. Something with piping and calculating the sha1 on the fly, directing the output to /dev/null
This would make it possible to verify backups without copying the file over the network or extracting it which is both resource consuming.
This is basically the same question as How to create sha1 checksums of files inside a tar archive without using much disk space which has a great answer, but I realized only later that the busybox tar binary is a minimal version which does not have the --to-command=sha1sum
option.