Today I will speak about pv command.
Pipe viewer - pv is a terminal-based tool for monitoring the progress of data through a pipeline written by Andrew Wood
To install pv on Fedora or CentOS do this:
$ sudo yum install pv
You can read the man file to get more help:
The result is:
NAME pv - monitor the progress of data through a pipe SYNOPSIS pv [OPTION] [FILE]... pv [-h|-V] DESCRIPTION pv allows a user to see the progress of data through a pipeline, by giving information such as time elapsed, percentage completed (with progress bar), current throughput rate, total data transferred, and ETA. To use it, insert it in a pipeline between two processes, with the appropriate options. Its standard input will be passed through to its standard output and progress will be shown on standard error.
Let's see some examples.
You can get precisely time how long it will take.
$ pv voronoi.py | python 737B 0:00:00 [86.9kB/s] [==================================>] 100%
You can see how fast the computer reads from /dev/zero.
$ pv /dev/zero > /dev/null 1.1GB 0:00:05 [ 2GB/s] [ <=> ]
You can use the dialog to show progressbar.
To do this you need to use -n arg.
$ (pv -n /dev/zero > /dev/null) 2>&1 | dialog --gauge "Please wait" 10 70 0