how do I configure postgresql to find the pg_controldata command I am trying to execute the pg_controldata command, I got the error command not found. Then I checked: 

 ls -l /usr/lib/postgresql/9.4/bin/ | grep "control"
-rwxr-xr-x 1 root root   25960 feb  5 18:24 pg_controldata


Well, there is a pg_controldata, then:


Why I got the error command not found?
What kind of configuration do I have to do to my postgresql or my sistem?


Please try an answer with a code or file configuration example.
Your shell PATH environment variable is not pointing to your folder /usr/lib/postgresql/9.4/bin/.

In order to do this, use the command PATH="/usr/lib/postgresql/9.4/bin/:$PATH".

If you want to automate this, you can add this line in your shell config file (ie. ~/.bashrc) with this :
echo 'PATH="/usr/lib/postgresql/9.4/bin/:$PATH"' &gt; ~/.bashrc.