Swish - Swift Shell

Execute shell scripts from your Swift scripts.

If you’ve been into scripting in Swift for awhile, you noticed that you can get rid of most of the basic shell scripting commands, but sometimes you still need to access certain shell commands, or want to create wrappers around CLI such as fastlane and bundler.

This package solves the issues where your Swift script can’t find the same executables as your regular shell.

With Swish, you can run bundler and fastlane from Swift scripts, as well as any arbitrary shell script, effortlessly.

Installation

Swish is available via Swift Package Manager. You can import it by modifying your Package.swift, adding Swish to your packade dependencies:

…
dependencies: [
    …
    .package(url: "https://github.com/rogerluan/Swish", from: "0.1.0"),
],
targets: [
    .target(
        …
        dependencies: [
            …
            "Swish",
            ]
        ),
    …
]

Usage

Single Command

sh(launchPath: "/bin/zsh", arguments: "echo", "Hello", "World")

Full script

With no arguments

execute(shellScript:
    """
    #!/bin/sh
    echo Hello World
    """, arguments: "")
// Hello World

With arguments

execute(shellScript:
    """
    #!/bin/sh
    echo "$1 $2"
    """, arguments: "Roger that")
// Roger that

Quoted arguments

execute(shellScript:
    """
    #!/bin/sh
    echo "$1"
    """, arguments: #""Roger that""#)
// Roger that

Fastlane

Executes fastlane, first attempting to execute it via bundler and, if not possible, it looks for the fastlane binary installed globally in your system by looking up the PATH environment variable.

fastlane("[lane]", "key:value", "key2:value2")

fastlane("deploy", "submit:false", "build_number:24")

Bundler

Executes bundle exec using the bundler executable indicated by your environment PATH variable.

bundleExec("fastlane", "deploy", "submit:false", "build_number:24")

bundleExec("jazzy", "--clean", "--output", "docs/swift", "--theme", "fullwidth")

Design details

Global Scope

At first I was concerned about releasing these set of utilities in the global scope, but it might actually make sense. Still on the fence, but if you’re facing issues (such as collisions or lack of clarity), you can always namespace under Swish module name.

Forwarding Stdout

I decided to remove the capture/forwarding of the standard and error outputs because you shouldn’t need to manipulate them. If your script needs to read the output of a bash script, you can probably perform the same task using pure Swift instead.

Also, if you execute programs that print an asynchronous stream of text, if you override stdout, you will only be able to capture the first blast of the stream (for example the first line), instead of the entire stream.

If you have issues with this design, I’m happy to discuss and adjust this as needed, maybe allowing further customization.

Contact

@rogerluan_

License

Swish is licensed under a standard 2-clause BSD License. That means you have to mention Roger Oba as the original author of this code and reproduce the LICENSE text inside your app.