howto's

Ever wondered how many bytes of space are there left to transfer while doing a dd with a large image ?

Well, dd has a built-in trick in order to help you doing this.

Right from its man page, introducing now the magic :

Sending a USR1 signal to a running `dd’ process makes it print I/O statistics to standard error and then resume copying.

$ dd if=/dev/zero of=/dev/null& pid=$!
$ kill -USR1 $pid; sleep 1; kill $pid

18335302+0 records in 18335302+0 records out 9387674624 bytes (9.4 GB) copied, 34.6279 seconds, 271 MB/s

Pretty neat, huh ?