readonly

readonly

The readonly command in Linux is used to make a file or directory read-only. This can be useful to protect a file or directory from being modified accidentally or maliciously.

The readonly command is used in the following syntax:

readonly [options] [file]

The file is the file or directory to make read-only. If no file is specified, the current directory will be made read-only.

The options can be used to specify the following:

• -f : Make the file read-only even if it is open.

• -r : Make the directory read-only even if it contains subdirectories.

For example, to make the file myfile read-only, you would run the following command:

readonly myfile

This command will make the file myfile read-only. If you try to write to the file, you will get an error message.

To make the directory mydir read-only, you would run the following command:

readonly -r mydir

This command will make the directory mydir read-only. You will still be able to read files in the directory, but you will not be able to create new files or modify existing files.

The readonly command is a versatile tool that can be used to protect files and directories from being modified accidentally or maliciously. It is a simple command to use and is supported by most Linux distributions.

Here are some additional things to note about the readonly command:

• The readonly command can be used to make a file or directory read-only even if it is open.

• The readonly command can be used to make a directory read-only even if it contains subdirectories.

• The readonly command can be used to protect files and directories from being modified accidentally or maliciously.

• The readonly command is a simple command to use and is supported by most Linux distributions.

help

readonly: readonly [-aAf] [name[=value] ...] or readonly -p
    Mark shell variables as unchangeable.
    
    Mark each NAME as read-only; the values of these NAMEs may not be
    changed by subsequent assignment.  If VALUE is supplied, assign VALUE
    before marking as read-only.
    
    Options:
      -a        refer to indexed array variables
      -A        refer to associative array variables
      -f        refer to shell functions
      -p        display a list of all readonly variables or functions,
                depending on whether or not the -f option is given
    
    An argument of `--' disables further option processing.
    
    Exit Status:
    Returns success unless an invalid option is given or NAME is invalid.