readonly - mark variables as readonly.
readonly name[=value] ...
readonly is a POSIX special builtin provided by Rush. Mark variables as readonly.
This page summarizes the builtin in Rush documentation. POSIX is the normative reference for detailed portable behavior.
See the POSIX definition for command-specific status rules. Usage errors generally return a non-zero status.
rush-builtins(7), POSIX Shell Command Language.