LinuxCommandLibrary

roll

Generate random numbers within specified ranges

TLDR

Roll 3 6-sided dice and sums the results

$ roll [3d]
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Roll 1 8-sided die, add 3 and sum the results
$ roll [d8 + 3]
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Roll 4 6-sided dice, keep the 3 highest results and sum the results
$ roll [4d6h3]
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Roll 2 12-sided dice 2 times and show every roll
$ roll --verbose [2{2d12]}
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Roll 2 20-sided dice until the result is bigger than 10
$ roll "[2d20>10]"
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Roll 2 5-sided dice 3 times and show the total sum
$ roll --sum-series [3{2d5]}
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SYNOPSIS

roll [options] [command]

PARAMETERS

--help
    Display help message and exit.

--version
    Show program's version number and exit.

snapshot
    Create a new snapshot.

rollback
    Roll back to the specified snapshot.

list
    List available snapshots.

delete
    Delete specified snapshots.

DESCRIPTION

The roll command, part of the btrfs-tools suite, is designed to simplify the process of taking snapshots and rolling back to previous states within a Btrfs filesystem. It provides a user-friendly interface for managing snapshots, hiding the complexities of directly manipulating Btrfs subvolumes. Essentially, it allows users to easily revert their system to a known good state after undesirable changes, such as a failed software installation or configuration error. Roll relies on pre-existing snapshot mechanisms of Btrfs, adding a layer of abstraction for easier usage.

The command typically works by creating snapshots before significant system changes (e.g., installing updates) and then, if necessary, reverting to one of those snapshots. This minimizes the impact of issues and simplifies the recovery process. Using roll effectively requires careful planning of snapshot frequency and storage management to avoid excessive disk space consumption. Roll offers features like automated snapshot management based on system events. The exact functionalities and configuration options depend on the specific implementation of roll provided by your distribution.

CAVEATS

Requires a Btrfs filesystem. The precise implementation and availability of the `roll` command, as well as its features, can vary greatly across different Linux distributions and versions of btrfs-tools. Always consult the documentation specific to your system. Incorrect usage can lead to data loss.

SNAPSHOT NAMING

It's crucial to establish a consistent naming convention for snapshots to easily identify and manage them. Include the date and time in the snapshot name, along with a short description of the system state captured.

SEE ALSO

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