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46 lines
1.3 KiB
Markdown
46 lines
1.3 KiB
Markdown
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# The readonly builtin command
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## Synopsis
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readonly [-p] [-a] [-A] [-f] [NAME[=VALUE] ...]
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## Description
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The `readonly` builtin command is used to mark variables or functions as
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read-only, which means unchangeable. This implies that it can\'t be
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unset anymore. A `readonly` variable may not be redefined in child
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scopes. A readonly global may not be redefined as a function local
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variable. Simple command environment assignments may not reference
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readonly variables.
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### Options
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Option Description
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-------- ------------------------------------------------------------------------------------------------------------------------
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`-a` refer to normal arrays
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`-A` refer to associative arrays
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`-f` refer to functions
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`-p` print all read-only variables or functions, `-a`, `-A` and `-f` can be used to filter. The output is reusable as input
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An argument of `--` disables further option processing.
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### Return status
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Status Reason
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-------- --------------------------------
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0 no error
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!=0 invalid option
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!=0 invalid combination of options
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!=0 a given `NAME` is invalid
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## Examples
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## Portability considerations
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- in POSIX(r), only the `-p` option is specified
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## See also
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- [declare](/commands/builtin/declare)
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- [unset](/commands/builtin/unset)
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