bash: Variable substitution - Use word if variable name set otherwise use nothing.

indigowinged

Take into account the main readme for this section. README first.

Syntax is:
${name+word}

if the variable $name is set, then substitute word otherwise use nothing.

Here Brazil is set, has a value of SugarCane

$ Brazil=SugarCane
$ Amazon=${Brazil+NoDeforestation}
$ echo $Amazon
NoDeforestation

Now change Brazil to Brazil1 and try again

$ Amazon=${Brazil1+NoDeforestation}
$ echo $Amazon

$