API for chmod

[peter-ahe-google]

I just tried using a Dart script in our build system as an alternative to python, see: https://chromiumcodereview.appspot.com/9454026/

The script dart/utils/dartdoc/build_helper.dart is supposed to write another executable Dart script in the output location. The idea is that just like you can type out/Release_ia32/dart to run the Dart VM, you can type out/Release_ia32/dartdoc to invoke dartdoc.

Unfortunately, there doesn't seem to be a way to make the output file executable from the Dart script.

[madsager]

Added Accepted label.

[madsager]

Added this to the Later milestone.

[sgjesse]

Removed Type-Defect label.
Added Type-Enhancement label.

[sgjesse]

For now one can use Process.run or Process.runSync to run chmod.

Using Process.run and returning a future:

Future makeExecutable(File file) {
  if (!Platform.isWindows) {
    return Process.run("chmod", ["u+x", file.path]).then((result) {
      if (result.exitCode != 0) throw new Exception(result.stderr);
    });
  }
}

main() {
  File file = new File("script.dart");
  file.exists().then(() {
      if () return file.delete();
    }).then(() {
      new File("script.dart").openWrite()
          ..writeln("#!out/ReleaseIA32/dart")
          ..writeln()
          ..writeln("main() {")
          ..writeln(" print('Hello, world!');")
          ..writeln("}")
          ..close()
          .then(() => makeExecutable(file))
          .then((_) => print("Done"));
    });
}

Using Process.runSync and no return value:

void makeExecutableSync(File file) {
  if (!Platform.isWindows) {
    var result = Process.runSync("chmod", ["u+x", file.path]);
    if (result.exitCode != 0) throw new Exception(result.stderr);
  }
}

main() {
  File file = new File("script.dart");
  file.exists().then(() {
      if () return file.delete();
    }).then(() {
      new File("script.dart").openWrite()
          ..writeln("#!out/ReleaseIA32/dart")
          ..writeln()
          ..writeln("main() {")
          ..writeln(" print('Hello, world!');")
          ..writeln("}")
          ..close()
          .then(() {
              makeExecutableSync(file);
              print("Done");
          });
    });
}

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Removed Priority-Medium label.
Added Priority-Low label.

[andersjohnsen]

Added Duplicate label.
Marked as being merged into #15078.

[kevmoo]

Removed Area-IO label.
Added Area-Library, Library-IO labels.