Mark a variable or function as read-only.
Syntax readonly [-apf] [name[=word] ...] Key -a Restrict the variables to arrays -p Display output in a format that can be reused as input -f Mark functions corresponding to the names as read-only
The given names are marked readonly; the values of these names can not be changed by subsequent assignment.
If no name arguments are given,or if the -p option is supplied, a list of all readonly names is printed.
If a variable name is followed by =word, the value of the variable is set to word.
The return status is 0 unless an
invalid option is encountered, one of the names is not a valid shell variable name, or -f is supplied with a name that is not a function.
readonly is a bash builtin command.
“The universe is like a safe to which there is a combination. But the combination is locked up in the safe” ~ Peter De Vries
set - Set a shell variable = value