NAME
    readonly - Mark shell variables as unchangeable.

SYNOPSIS
    readonly [-aAf] [name[=value] ...] or readonly -p

DESCRIPTION
    Mark shell variables as unchangeable.
    
    Mark each NAME as read-only; the values of these NAMEs may not be
    changed by subsequent assignment.  If VALUE is supplied, assign VALUE
    before marking as read-only.
    
    Options:
      -a	refer to indexed array variables
      -A	refer to associative array variables
      -f	refer to shell functions
      -p	display a list of all readonly variables or functions,
    		depending on whether or not the -f option is given
    
    An argument of `--' disables further option processing.
    
    Exit Status:
    Returns success unless an invalid option is given or NAME is invalid.

SEE ALSO
    bash(1)

IMPLEMENTATION
    GNU bash, version 5.0.17(1)-release (x86_64-redhat-linux-gnu)
    Copyright (C) 2019 Free Software Foundation, Inc.
    License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>