Sly

A CLI tool utilizing plain Bash functions.

⚠️ Important! Sly is only tested on Linux, with bash and zsh

Install

$ curl -Lo- git.io/sly-install | bash

Slyfile

Create a Slyfile in the current directory:

$ sly --init

Add functions to the Slyfile. They may contain any Bash code. Functions starting with an underscore (e.g. _certs) are considered "private" and won't be shown using sly --list to keep that tidy.

Simple example

Note: either the shorthand (foo() {}) or the long notation (function foo {}) can be used to define functions

example() {
  width=${1-12}
  length=${2-5}
  area=$((width * length))
  echo "Area is: $area (${width} x ${length})"
  [ "$width" == "$length" ] && echo "It's a square"
  echo "And the current directory is: $(pwd)"
  echo "Calling 'uname -a':"
  uname -a
}

To run this example, try these commands for different output:

• sly example
• sly example 2 5
• sly example 3 3

Remember, it's just plain bash. No magic.

A real-world example

This is a set of functions used for a Django project running on Docker:

#!/usr/bin/env bash
#
### Slyfile - used by sly
### https://github.com/richarddewit/sly

# Variables/aliases
dc="docker-compose"
manage="$dc exec app python manage.py"

start() {
  # Start containers
  $dc up -d --build
}

stop() {
  # Stop containers
  $dc down
}

restart() {
  # Combine functions
  stop
  start
}

logs() {
  # Watch logs
  # Run `sly logs` to log all containers, `sly logs app` to only log
  # the `app` container
  if [ -n "$1" ]; then
    $dc logs -f "$1"
  else
    $dc logs -f
  fi
}

python() {
  # Run interactive shell inside `app` container
  $manage shell
}

manage() {
  # Run `manage.py` commands in `app` container
  # Use `$@` to pass along all arguments of the function
  $manage "$@"
}

m() {
  # Define custom shortcut functions
  # Now you can run `sly m makemigrations`
  $manage "$@"
}

test() {
  # Run tests in `app` container
  $manage test
}

psql() {
  # Run postgres shell in `db` container
  $dc exec db psql -U postgres
}

sync() {
  # Synchronise the lock- and requirements file
  # with the installed packages
  pipenv lock
  pipenv lock --requirements > requirements.txt
}