Rust Cuts

What?

Supercharged terminal aliases.

Save a list of named commands, and run them with rc. No need to hit Ctrl-R and spend ages scrolling through your history to remember the command you need. Easier than creating aliases because you can template the command with values that are be prompted for, as well as specifying a working directory or environment variables to always use for the command.

Setup

Rust and build tools (cargo) must be installed. Get these from rustup.rs

Clone this repository and build/install from source with:

$ cargo install --path .

Next create the directory ~/.rust-cuts/ and definition YAML file ~/.rust-cuts/commands.yml. See sample-commands.yml for an example.

Simple Example

Basic Hello World example:

- name: "Do hello world!"
  command: ["echo", "Hello world!"]

When executing:

$ rc
[0]: Do hello world!
Enter an option (0-0. Quit with `q`): 0
Executing command:
echo Hello world!
Are you sure you want to run? ([Y]es/[n]o): y
Hello world!

Templates

Template tokens are specified inside braces {}.

In this example, we want to SSH to different AWS EC2 instances that have been created, all which use the shared SSH key stored in AWS, but have different usernames and hosts (as they are created).

The username and host portion of the command is templated.

This is added to the commands.yml:

- name: "Do hello world!"
  command: ["echo", "Hello world!"]
- name: "SSH to EC2"
  command: ["ssh", "-i", "~/path/to/aws-key.pem", "{username}@{host}"]

Execute rc:

➜  ~ rc
[0]: Do hello world!
[1]: SSH to EC2
Enter an option (0-1. Quit with `q`): 1
Please give value for `host`: 10.1.2.3
Please give value for `username`: ec2-user
Executing command:
ssh -i ~/path/to/aws-key.pem ec2-user@10.1.2.3
Are you sure you want to run? ([Y]es/[n]o/[c]hange parameters): y
… SSH session starts…

Defaults for parameters

Specify a list of parameters for a command, each with a name and default. The name must match the value for a template token. If no input is given when prompted, the default will be used.

We can update the previous example to provide a default for username:

- name: "SSH to EC2"
  command: ["ssh", "-i", "~/path/to/aws-key.pem", "{username}@{host}"]
  parameters:
    - name: "username"
      default: "ubuntu"

Now, if no value is provided, it defaults to ubuntu:

➜  ~ rc
[0]: Do hello world!
[1]: SSH to EC2
Enter an option (0-1. Quit with `q`): 1
Please give value for `host`: 10.1.2.3
Please give value for `username` [ubuntu]:
Executing command:
ssh -i ~/path/to/aws-key.pem ubuntu@10.1.2.3
Are you sure you want to run? ([Y]es/[n]o/[c]hange parameters): y
… SSH session starts…

Working Directory

Specify a working_directory for command to change into that directory before executing. All paths will now be relative to that directory.

In this example, make build is executed inside a project directory.

- name: "Build project"
  command: ["make", "build"]
  working_directory: "~/projects/rust-cuts/"

rc executes the command and returns to the original directory afterward.

Environment Variables

Environment variables are specified in the environment dictionary for the command, as key-value pairs. For example, if there's a command that should always be run as a specific AWS profile, it can be specified as an environment variable.

This example lists objects in an S3 bucket, using the aws CLI tool. The AWS profile environment variable AWS_PROFILE is always set to dev, so the dev profile is used for authentication.

- name: "List objects in S3 bucket"
  command: ["aws", "s3", "ls", "{bucket}"]
  environment:
    AWS_PROFILE: dev

Rerun Last Command

To rerun the previous command, type r at the command list. You have the opportunity to enter new values for parameters.

Or, to automatically select the last command, execute rc -r. You will be prompted to confirm the command to run, and will have the chance to update parameters.

To force run the last command, without confirming or changing parameters, execute with the force flag as well, or rc -rf.

Execution in Shell

Commands are executed inside your shell, so normal aliases and shell expansion is available.

Commands are not escaped, so shell injection is possible. This is by design, but may change.

You should escape values that are prompted. In this simple example the command cats a file:

- name: "cat a file"
  command: ["cat", "{path}"]

When entering path, either quote the input or use backslashes before spaces.

Here is how various inputs will behave.

This first example has space separated values:

Please give value for `path`: file1.txt file2.txt

This will cat file1.txt and file2.txt.

By using quotes a path with spaces can be used:

Please give value for `path`: "file with spaces.txt"

Similarly, backslashes can be used:

Please give value for `path`: file\ with\ spaces.txt

Both of these will cat the file file with spaces.txt.

beneboy/rust-cuts