sheller 0.5.1

Ergonomic scripting in Dart. Utilities for interacting with shells and converting output to Dart types.

sheller

Ergonomic scripting in Dart. Utilities for interacting with shells and converting output to Dart types.

List<File> files = $("cd $dir && find . -maxdepth 1 -type f").lines();

Table of Contents

1. Example
2. Valid Conversion Types
3. Custom Conversion Types
4. Real Use Case - Protobuf Package Generation Script Example

Example

With Sheller you can esaily write sync or async Dart scripts that interact with the host platform on Linux, MacOs, or Windows.

import 'sheller/sync.dart';
// import 'sheller/async.dart'; // alternative

// Linux
void main() {
  // run process and print stdout to terminal
  print($("netstat")());
  // run process and convert to Dart type
  int number = $("echo 1")();
  assert(number == 1);
  // built in support for types like json
  String data ='{\\"id\\":1, \\"name\\":\\"lorem ipsum\\", \\"address\\":\\"dolor set amet\\"}';
  Map<String, dynamic> json = $('echo $data')();
  assert(json.entries.length == 3);
  // split by spaces then convert
  List<double> doubleList = $('echo 1  2   3').spaces();
  assert(doubleList.length == 3);
  // The class
  $ shellClassInstance = $("echo 1");
  int id = shellClassInstance.pid;
  int exitCode = shellClassInstance.exitCode;
  int convertedResult = shellClassInstance();
  assert(convertedResult == 1);
  // split by lines then convert
  List<File> files = $("find . -maxdepth 1 -type f").lines();
  // Writing to a file
  $("echo 1") > File("./temp");
  // Appending to a file
  $("echo 2") >> File("./temp");
}

Valid Conversion Types

Built in conversions for stdout of successful shells to

int
double
num
BigInt
String
bool // empty is false, non-empty is true.
Map<String, dynamic>
Object
FileSystemEntity
Directory
File
Link

Custom Conversion Types

Easily add your own custom conversion types. e.g.

class IntConverter extends Converter<String, int> {
  const IntConverter();

  @override
  int convert(String input) {
    int? result = int.tryParse(input);
    if (result == null) {
      throw ShellResultConversionException(int, input);
    }
    return result;
  }
}

ShellConfig.addConverter(const IntConverter());

Real Use Case - Protobuf Package Generation Script Example

void main() async {
  String osPathSeparator = path.separator;
  if(Directory.current.path.split(osPathSeparator).last != "generator") throw StateError("Launched from wrong current directory.");
  if(Directory("bin").listSync(recursive: true).length != 1) throw StateError("Directory not clean.");
  const protoFilesDir = "../../proto";
  const outputDir = "../generated";
  const outputSrcDir = "../generated/lib/src";
  if(Directory(outputDir).existsSync()){
    Directory(outputDir).deleteSync(recursive: true);
  }
  Directory(outputSrcDir).createSync(recursive: true);

  final protoFiles = Directory(protoFilesDir)
      .listSync()
      .whereType<File>()
      .where((file) => file.path.endsWith(".proto"))
      .map((file) => file.path)
      .toList();

  final command = "protoc -I=$protoFilesDir --dart_out=grpc:$outputSrcDir ${protoFiles.join(' ')}";
  print($(command)());

  // Contains desired pubspec.yaml
  const toCopyOver = "./to_copy_over";
  print($("cp -r $toCopyOver/* $outputDir")());

  final generateBarrelFileCommand = "cd $outputDir && dart pub run index_generator";
  print($(generateBarrelFileCommand)());
  print("Done.");
}