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 unchangable. Tis implies that it can't be unset anymore.


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


Portability considerations

  • in POSIX®, only the -p option is specified

See also


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