Setting Permanent Global Environment Variables for All LINUX code example

Example 1: set permanant environemt variable

$EDITOR ~/.profile
#add lines at the bottom of the file:  
     export LD_LIBRARY_PATH=/usr/lib/oracle/11.2/client64/lib
     export ORACLE_HOME=/usr/lib/oracle/11.2/client64

Example 2: remove environment variable linux

$ unset <var-name>

Example 3: bash delete env variable

unset GNUPLOT_DRIVER_DIR

Example 4: linux set environment variable

# Linux - Bash 

# syntax 
# export *<variable-name>=*<variable-value>;

# example 
export ORACLE_SID='sales_database';