Added ability to get process parent, name and list of processes.

[bsutton]

I'm the author of dshell which provides a library for building cli apps with dart.

https://github.com/bsutton/dshell/

One of the core drivers is to replace bash with dart.

When building these types of apps a common operation is to get details of a running process.

Specifically

A list of running processes.
The name of an existing process
The parent pid of of a process [the more specialised use case is the parent of the current process].

I'm currently doing this by calling out to 'tasklist' on windows and 'ps' under linux.
The problem is these methods are not reliable (particularly under linux) as not all distros have the required tooling.
For example we do a lot of work in docker containers and the availability of 'ps' is not the norm.

My suggestion would be something like:

class Process
{
static List<Process> Process.list();

Process  get parent ();

Process get forPid(int pid);

String get name;

/// less important but useful.

bool get isRunning;

/// returns the path to the exec that started the process.
String get path;


}

Having these methods in the core sdk would make this work far easier.

Dart VM version: 2.8.4 (stable) (Unknown timestamp) on "linux_x64"