Progress of long processes in BASH

You can view progress of your process execution in UNIX using pv or bar. With pv, you can even report progress of multiple modules of your pipeline.

This is very useful for tracing large database dump/restore progress:

pv -cN gzip backup.sql.gz | gzip -d | pv -cN mysql | mysql
  mysql:  799MiB 0:06:30 [1.68MiB/s] [       <=>   ]
   gzip:  173MiB 0:06:30 [ 250kiB/s] [=>           ]  4% ETA 2:25:09

TAR random access   Multiprocessing in Python and garbage collection