linux environment setting sudo

I have encountered the same problem twice until I met a simple solution to the following problem tonight:

could not find java, set java_home

which is caused by enviornment variables are reset when getting into the super user mode.

To keep your enviorment variables. use -E after sudo, which helps to maintain the path variables even enter the super user mode. For example,

sudo -E  apt-get install ./elasticsearch-6.8.1.deb

Here’s more detail about -E

  -E   The -E (preserve environment) option indicates to the security policy that the user wishes
       to preserve their existing environment variables.  The security policy may return an error 
       if the -E option is specified and the user does not have permission to preserve the environment

Reference:

[1]. https://stackoverflow.com/questions/12309253/sudo-java-command-not-found-after-exiting-from-root-user