grav

A (work-in-progress) tui-based nbody simulation program written in rust.

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Usage

grav is invoked with one of a few different "subcommands" on the command line: help,, ``load, or new`. The `new` subcommand starts a new simulation with either the default parameters and starting condition, or with the specification defined in a simulation configuration YAML file:

$ grav new --config 'example.yaml'

The load subcommand allows the user to load a previously-saved simulation file. We'll cover the subcommands in more detail below.

Common CLI Arguments

The following table describes the program's common CLI arguments:

Argument(s)	Description
-h, --help	Displays help and usage information.
-f, --log-file	Specifies the log file to write to.
-l, --log-level	Specifies the log level of the program.
-M, --log-mode	Specifies whether to append to or overwrite the specified log file.
-V, --version	Displays version information.

Each of the above options has the following set of corresponding value types and default values:

Argument(s)	Value Type / Possible Values	Default Value
-f, --log-file	File Path	grav.log
-l, --log-level	disabled, error, warning, info, debug, or trace	info
-M, --log-mode	append or overwrite	append

Environment Variables

The default behavior of the grav program may also be configured via environment variables. Each environment variable has a corresponding command-line argument, as described in the table below:

Environment Variable	Correpsonding CLI Argument
GRAV_LOG_FILE	--log-file
GRAV_LOG_LEVEL	--log-level
GRAV_LOG_MODE	--log-mode