Bash Variable Substitution

Changing case to upper or lower

Sources: scriptingosx.com

$ name="John Doe"
$ echo ${name,,}
john doe

$ echo ${name^^}
$ JOHN DOE

$ name="JOHN"
$ echo "${name,}"
jOHN

$name="john"
$echo "${name^}"
John

For zsh

% name="John Doe"
% echo ${name:l}
john doe
% echo ${name:u}
JOHN DOE