EXPORT -- To set environmet variables

export
Set an environment variable. Mark each name to be passed to child processes in the environment.

SYNTAX
export [-fn] [-p] [name[=value]]

OPTIONS
-f The names refer to shell functions;
otherwise the names refer to shell variables
-n No longer mark each name for export.
-p Display output in a form that may be reused as input.

If no names are supplied, or if the `-p' option is given, a list of exported names is displayed.
The return status is zero unless an invalid option is supplied, one of the names is not a valid shell variable name, or `-f' is supplied with a name that is not a shell function.

Example - local variables
var=value
echo $var

Example - global variables
var=value ; export var
[Now var is global variable]


Related Linux Bash commands:

env - Display, set, or remove environment variables
local - Create variables
printenv - Print environment variables
readonly - Mark variables/functions as readonly
unset - Remove variable or function names