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tldr/pages/common/readonly.md
Alejandro Cervera ced5cb22f6
common/*: update pages of POSIX special Built-In utilities (#11858)
* eval, exec, exit, export, readonly, set, shift, trap: use Open Group links

* exec, export, trap: split Linux and POSIX
2023-12-29 18:37:58 +05:30

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readonly

Create or modify read-only variables within a shell script, preventing the variable from being changed by subsequent commands. This is useful when you want to ensure that a variable retains a constant value throughout the execution of a script. More information: https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#readonly.

  • Create a read-only variable:

readonly {{variable_name}}={{value}}

  • Mark a variable as read-only:

readonly {{existing_variable}}

  • [p]rint the names and values of all read-only variables to stdout:

readonly -p