mirror of
https://github.com/rawiriblundell/wiki.bash-hackers.org
synced 2024-12-26 06:20:41 +01:00
39 lines
1.2 KiB
Markdown
39 lines
1.2 KiB
Markdown
====== The readonly builtin command ======
|
|
|
|
===== Synopsis =====
|
|
|
|
<code>
|
|
readonly [-p] [-a] [-A] [-f] [NAME[=VALUE] ...]
|
|
</code>
|
|
|
|
===== Description =====
|
|
|
|
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 |
|
|
|
|
===== Examples =====
|
|
|
|
===== Portability considerations =====
|
|
|
|
* in POSIX(r), only the ''-p'' option is specified
|
|
|
|
===== See also =====
|
|
|
|
* [[commands:builtin:declare]]
|