Runner

A simple, lightweight task runner for Bash.

Runner was made to replace Make in those few use cases, when all you need is a bunch of .PHONY targets that are simple shell scripts. It uses a familiar Bash syntax and only depends on bash and coreutils.

In addition, Runner provides tools to run tasks in parallel for improved performance, nice logging facilities and error handling.

Table of contents

• Dependencies
• Installation
  • Simple (vendored)
  • Submodule (vendored)
  • Homebrew
  • NPM
  • Git + PATH
• CLI
  • Autocompletion
  • Flag propagation
• Runnerfile
  • Naming convention
  • Default task
  • Task chaining
  • Error handling
• Function reference
  • runner_log [message]
  • runner_colorize <color> [message]
  • runner_run [command]
  • runner_get_defined_tasks
  • runner_is_defined <name>
  • runner_is_task_defined [task...]
  • runner_sequence [task...]
  • runner_parallel [task...]
  • runner_bootstrap
• Contribution
• License
• Contacts

Dependencies

Runner depends on:

• bash >=4.2
• coreutils >=8.0

For non-GNU environments, it also depends on:

• perl >=5.0 (for resolving symlinks)

Note for macOS users:

Runner should work with bash version 3.2 and macOS version of coreutils, but that way you will miss a lot of the fancy stuff that comes with the Runner.

For improved experience, use Homebrew to install the missing dependencies:

brew install bash coreutils

Installation

Each of the below installation methods is differentiated along two properties:

• Local to project
  • Whether Runner will be installed locally to your project or globally on a system.
  • This is good for CI builds and spinning up multiple people on your project
• CLI-enabled
  • Whether you will be able to use the runner command from your prompt.
  • Useful for local development, tab completion, and convenience.

You may want to combine multiple installation methods in order to satisfy both of these requirements. In particular, we recommend Simple (vendored) with a method that gives you a CLI and is compatible with your system.

	Local to Project	CLI-enabled
Simple (vendored)	✅	🚫
Submodule (vendored)	✅	✅
Homebrew	🚫	✅
NPM	✅	✅
Git + PATH	🚫	✅

Simple (vendored)

Just drop src/runner.sh anywhere in your project folder:

wget https://raw.githubusercontent.com/stylemistake/runner/master/src/runner.sh

Then skip to Runnerfile for how to use a vendored Runner installation.

Submodule (vendored)

If you'd like a slightly better story around updating Runner when vendored, you can use a Git submodule, if you're familiar with submodules:

git submodule add https://github.com/stylemistake/runner

Note that if submodules are too heavy-handed, you can get the same effect (without the ease of updating) by just unzip'ing Runner's source into your project.

You should now be able to access runner.sh within the submodule. Additionally, you can access the CLI with ./runner/bin/runner. You can make this more ergonomic by altering your PATH:

export PATH="$PATH:./runner/bin"

To avoid modifying your path, you can add runner as a git alias:

git config alias.runner = '!f(){ bash ./runner/bin/runner $@; }; f'
# runner can now be called as
git runner

Note this will prevent the runner from recognizing --help, but will still allow using -h to print the usage documentation.

Then skip to CLI to learn how to use the CLI.

Homebrew

On OS X, installing Runner globally is simple if you have Homebrew:

brew install stylemistake/formulae/runner

Then skip to CLI to learn how to use the CLI.

NPM

If you don't mind the additional dependency on the NPM ecosystem, you can install Runner with NPM:

# --- Local to Project --- #
npm install --save bash-task-runner

# to enable CLI:
export PATH="PATH:./node_modules/.bin"

# --- Global --- #
npm install -g bash-task-runner

Then skip to CLI to learn how to use the CLI.

Git + PATH

If Runner is not available in a package manager for your system, you can clone Runner to your computer, and adjust your PATH to contain the installation location:

git clone https://github.com/stylemistake/runner

export PATH="$PATH:$(pwd)/runner/bin"

Then skip to CLI to learn how to use the CLI.

CLI

Please see runner -h for complete, up-to-date CLI usage information.

Usage: runner [options] [task] [task_options] ...
Options:
  -C <dir>, --directory=<dir>  Change to <dir> before doing anything.
  --completion=<shell>         Output code to activate task completions.
                               Supported shells: 'bash'.
  -f <file>, --file=<file>     Use <file> as a runnerfile.
  -l, --list-tasks             List available tasks.
  -v, --version                Print the version of runner used
  -h, --help                   Print this message and exit.

Autocompletion

The runner CLI supports autocompletion for task names and flags. Add the following line your ~/.bashrc:

eval $(runner --completion=bash)

Flag propagation

All flags you pass after the task name are passed to your tasks.

$ runner foo --production

task_foo() {
    echo ${@} # --production
}

To pass options to the runner CLI specifically, you must provide them before any task names:

$ runner -f scripts/tasks.sh foo

Runnerfile

Runner works in conjunction with a runnerfile.sh. A basic Runnerfile looks like this:

task_foo() {
    ## Do something...
}

task_bar() {
    ## Do something...
}

Invoke Runner using runner [task...]:

$ runner foo bar
[23:43:37.754] Starting 'foo'
[23:43:37.755] Finished 'foo' after 1 ms
[23:43:37.756] Starting 'bar'
[23:43:37.757] Finished 'bar' after 1 ms

Optional: If you want the Runnerfile to be a standalone script, add this to the beginning (works best in conjunction with a vendored installation):

#!/usr/bin/env bash
cd "$(dirname "$0")" || exit
source <path_to>/runner.sh

To invoke such script, use bash runnerfile.sh [task...].

Naming convention

Your Runnerfile can be named any of the following. Using a .sh suffix helps with editor syntax highlighting.

• Runnerfile
• Runnerfile.sh
• runnerfile
• runnerfile.sh

Default task

You can specify a default task in your Runnerfile. It will run when no arguments are provided. There are two ways to do this:

task_default() {
    # do something ...
}

runner_default_task="foo"
task_foo() {
    # do something ...
}

Task chaining

Tasks can launch other tasks in two ways: sequentially and in parallel. This way you can optimize the task flow for maximum concurrency.

To run tasks sequentially, use:

task_default() {
    runner_sequence foo bar
    ## [23:50:33.194] Starting 'foo'
    ## [23:50:33.195] Finished 'foo' after 1 ms
    ## [23:50:33.196] Starting 'bar'
    ## [23:50:33.198] Finished 'bar' after 2 ms
}

To run tasks in parallel, use:

task_default() {
    runner_parallel foo bar
    ## [23:50:33.194] Starting 'foo'
    ## [23:50:33.194] Starting 'bar'
    ## [23:50:33.196] Finished 'foo' after 2 ms
    ## [23:50:33.196] Finished 'bar' after 2 ms
}

Error handling

Sometimes you need to stop the task if one of the commands fails. You can achieve this with a conditional return:

task_foo() {
    ...
    php composer.phar install || return
    ...
}

If a failed task was a part of a sequence, the whole sequence fails. Same applies to the tasks running in parallel.

Notice that you should use this pattern for the whole sequence too to ensure no further code is executed afterwards and the overall return code is correctly set:

task_default() {
    ...
    runner_sequence foo bar || return
    ...
    echo "Won't show up on error above"
}

Function reference

runner_log [message]

Prints a message with a timestamp. Variations of log with colors:

• runner_log_error (red)
• runner_log_warning (yellow)
• runner_log_success (green)
• runner_log_notice (gray)

runner_colorize <color> [message]

Colorizes the message with the specified color. Here's a list of colors:

• black
• red
• green
• yellow
• blue
• purple
• cyan
• light_gray
• gray
• light_red
• light_green
• light_yellow
• light_blue
• light_purple
• light_cyan
• white

runner_run [command]

runner_run command gives a way to run commands and have them outputted:

task_default() {
    runner_run composer install
    ## [12:19:17.170] Starting 'default'...
    ## [12:19:17.173] composer install
    ## Loading composer repositories with package information
    ## ...
    ## [12:19:17.932] Finished 'default' after 758 ms
}

runner_get_defined_tasks

Lists all functions beginning with task_.

runner_is_defined <name>

Checks if function is defined or program is accessible from current $PATH.

runner_is_task_defined [task...]

Checks if task name is defined.

runner_sequence [task...]

Runs tasks sequentially. If any task in the sequence fails, it stops execution and returns an error code of a failed task.

runner_parallel [task...]

Runs tasks in parallel, and lets them finish even if any error occurs. In case of an error, this command returns a special error code.

Error codes:

• 1 - one task has failed
• 2 - some tasks have failed
• 3 - all tasks have failed

runner_bootstrap

Launches the task runner. This can be used to override the default startup mechanism.

By default, task runner starts up when it reaches the end of a Runnerfile. By using runner_bootstrap, you can manually choose a point where it begins to run tasks:

task_default() {
    ## Do things...
}

runner_bootstrap ## <-- runs tasks here

if [[ ${?} -eq 0 ]]; then
    echo "Success! :)"
else
    echo "Failure! :("
fi

In example above, we used runner_bootstrap to create a code section, which handles the runner's exit code. You can use this to handle errors, do cleanup work or restart certain tasks when needed.

Contribution

Please provide pull requests in a separate branch (other than master), this way it's easier for me to review and pull changes.

Before writing code, open an issue to get initial feedback.

License

This software is covered by GNU Lesser General Public License v3 (LGPL-3.0). See LICENSE.md.

Contacts

Style Mistake <stylemistake@gmail.com>