The readonly builtin command

readonly [-p] [-a] [-A] [-f] [NAME[=VALUE] ...]

The readonly builtin command is used to mark variables or functions as read-only, which means unchangeable. This implies that it can't be unset anymore. A readonly variable may not be redefined in child scopes. A readonly global may not be redefined as a function local variable. Simple command environment assignments may not reference readonly variables.

Options

Option Description
-a refer to normal arrays
-A refer to associative arrays
-f refer to functions
-p print all read-only variables or functions, -a, -A and -f can be used to filter. The output is reusable as input

An argument of -- disables further option processing.

Return status

Status Reason
0 no error
!=0 invalid option
!=0 invalid combination of options
!=0 a given NAME is invalid
  • in POSIX┬«, only the -p option is specified
Enter your comment. Wiki syntax is allowed: