foo=one
 
printvalue() {
local foo=two
 
echo $foo
}
 
 
# This will print ''one'' to the console.
echo $foo
 
# This will print ''two'' to the console.
printvalue
 
# This will print ''one'' to the console.
echo $foo

One feature we will use for Scope is the system that exists in all Unix systems. For example, when we call a program in a script, all environment variables are copied into the scope of that program. In short, the variables we define in the called script can only be accessed if they are environment variables.

# create a new variable and set it:
# -> This is a normal variable, not an environment variable!
test_variable="Hello World."
 
# Let's make it visible to all sub-processes by converting it to an environment variable:
export test_variable

Taken from UCH Wiki. ===== EDITOR NOTES ===== https://wiki.ulascemh.com/doku.php?id=en:cs:bash:variable