3 files changed, 164 insertions, 2 deletions

diff --git a/js/deno.ts b/js/deno.ts
index 51cc0791a..46f018afc 100644
--- a/js/deno.ts
+++ b/js/deno.ts
@@ -68,7 +68,14 @@ export { FileInfo } from "./file_info";
 export { connect, dial, listen, Listener, Conn } from "./net";
 export { metrics, Metrics } from "./metrics";
 export { resources } from "./resources";
-export { run, RunOptions, Process, ProcessStatus } from "./process";
+export {
+  kill,
+  run,
+  RunOptions,
+  Process,
+  ProcessStatus,
+  Signal
+} from "./process";
 export { inspect } from "./console";
 export { build, platform, OperatingSystem, Arch } from "./build";
 export { version } from "./version";
diff --git a/js/process.ts b/js/process.ts
index a0eef63dd..c0a66f311 100644
--- a/js/process.ts
+++ b/js/process.ts
@@ -7,6 +7,7 @@ import { File, close } from "./files";
 import { ReadCloser, WriteCloser } from "./io";
 import { readAll } from "./buffer";
 import { assert, unreachable } from "./util";
+import { platform } from "./build";
 
 /** How to handle subprocess stdio.
  *
@@ -51,6 +52,16 @@ async function runStatus(rid: number): Promise<ProcessStatus> {
   }
 }
 
+/** Send a signal to process under given PID. Unix only at this moment.
+ * If pid is negative, the signal will be sent to the process group identified
+ * by -pid.
+ */
+export function kill(pid: number, signo: number): void {
+  const builder = flatbuffers.createBuilder();
+  const inner = msg.Kill.createKill(builder, pid, signo);
+  dispatch.sendSync(builder, msg.Any.Kill, inner);
+}
+
 export class Process {
   readonly rid: number;
   readonly pid: number;
@@ -113,6 +124,10 @@ export class Process {
   close(): void {
     close(this.rid);
   }
+
+  kill(signo: number): void {
+    kill(this.pid, signo);
+  }
 }
 
 export interface ProcessStatus {
@@ -179,3 +194,77 @@ export function run(opt: RunOptions): Process {
 
   return new Process(res);
 }
+
+// From `kill -l`
+enum LinuxSignal {
+  SIGHUP = 1,
+  SIGINT = 2,
+  SIGQUIT = 3,
+  SIGILL = 4,
+  SIGTRAP = 5,
+  SIGABRT = 6,
+  SIGBUS = 7,
+  SIGFPE = 8,
+  SIGKILL = 9,
+  SIGUSR1 = 10,
+  SIGSEGV = 11,
+  SIGUSR2 = 12,
+  SIGPIPE = 13,
+  SIGALRM = 14,
+  SIGTERM = 15,
+  SIGSTKFLT = 16,
+  SIGCHLD = 17,
+  SIGCONT = 18,
+  SIGSTOP = 19,
+  SIGTSTP = 20,
+  SIGTTIN = 21,
+  SIGTTOU = 22,
+  SIGURG = 23,
+  SIGXCPU = 24,
+  SIGXFSZ = 25,
+  SIGVTALRM = 26,
+  SIGPROF = 27,
+  SIGWINCH = 28,
+  SIGIO = 29,
+  SIGPWR = 30,
+  SIGSYS = 31
+}
+
+// From `kill -l`
+enum MacOSSignal {
+  SIGHUP = 1,
+  SIGINT = 2,
+  SIGQUIT = 3,
+  SIGILL = 4,
+  SIGTRAP = 5,
+  SIGABRT = 6,
+  SIGEMT = 7,
+  SIGFPE = 8,
+  SIGKILL = 9,
+  SIGBUS = 10,
+  SIGSEGV = 11,
+  SIGSYS = 12,
+  SIGPIPE = 13,
+  SIGALRM = 14,
+  SIGTERM = 15,
+  SIGURG = 16,
+  SIGSTOP = 17,
+  SIGTSTP = 18,
+  SIGCONT = 19,
+  SIGCHLD = 20,
+  SIGTTIN = 21,
+  SIGTTOU = 22,
+  SIGIO = 23,
+  SIGXCPU = 24,
+  SIGXFSZ = 25,
+  SIGVTALRM = 26,
+  SIGPROF = 27,
+  SIGWINCH = 28,
+  SIGINFO = 29,
+  SIGUSR1 = 30,
+  SIGUSR2 = 31
+}
+
+/** Signals numbers. This is platform dependent.
+ */
+export const Signal = platform.os === "mac" ? MacOSSignal : LinuxSignal;
diff --git a/js/process_test.ts b/js/process_test.ts
index c89e1cae7..8d266617a 100644
--- a/js/process_test.ts
+++ b/js/process_test.ts
@@ -1,6 +1,6 @@
 // Copyright 2018-2019 the Deno authors. All rights reserved. MIT license.
 import { test, testPerm, assert, assertEquals } from "./test_util.ts";
-const { run, DenoError, ErrorKind } = Deno;
+const { kill, run, DenoError, ErrorKind } = Deno;
 
 test(function runPermissions(): void {
   let caughtError = false;
@@ -223,3 +223,69 @@ testPerm({ run: true }, async function runEnv(): Promise<void> {
   assertEquals(s, "01234567");
   p.close();
 });
+
+testPerm({ run: true }, async function runClose(): Promise<void> {
+  const p = run({
+    args: [
+      "python",
+      "-c",
+      "from time import sleep; import sys; sleep(10000); sys.stderr.write('error')"
+    ],
+    stderr: "piped"
+  });
+  assert(!p.stdin);
+  assert(!p.stdout);
+
+  p.close();
+
+  const data = new Uint8Array(10);
+  let r = await p.stderr.read(data);
+  assertEquals(r.nread, 0);
+  assertEquals(r.eof, true);
+});
+
+test(function signalNumbers(): void {
+  if (Deno.platform.os === "mac") {
+    assertEquals(Deno.Signal.SIGSTOP, 17);
+  } else if (Deno.platform.os === "linux") {
+    assertEquals(Deno.Signal.SIGSTOP, 19);
+  }
+});
+
+// Ignore signal tests on windows for now...
+if (Deno.platform.os !== "win") {
+  testPerm({ run: true }, async function killSuccess(): Promise<void> {
+    const p = run({
+      args: ["python", "-c", "from time import sleep; sleep(10000)"]
+    });
+
+    assertEquals(Deno.Signal.SIGINT, 2);
+    kill(p.pid, Deno.Signal.SIGINT);
+    const status = await p.status();
+
+    assertEquals(status.success, false);
+    assertEquals(status.code, undefined);
+    assertEquals(status.signal, Deno.Signal.SIGINT);
+  });
+
+  testPerm({ run: true }, async function killFailed(): Promise<void> {
+    const p = run({
+      args: ["python", "-c", "from time import sleep; sleep(10000)"]
+    });
+    assert(!p.stdin);
+    assert(!p.stdout);
+
+    let err;
+    try {
+      kill(p.pid, 12345);
+    } catch (e) {
+      err = e;
+    }
+
+    assert(!!err);
+    assertEquals(err.kind, Deno.ErrorKind.InvalidInput);
+    assertEquals(err.name, "InvalidInput");
+
+    p.close();
+  });
+}