fix: sub process title on macOS (nodejs#616)

Author: deepak1556

src/native.d.ts

@@ -21,8 +21,7 @@ interface IWinptyNative {
 interface IUnixNative {
   fork(file: string, args: string[], parsedEnv: string[], cwd: string, cols: number, rows: number, uid: number, gid: number, useUtf8: boolean, helperPath: string, onExitCallback: (code: number, signal: number) => void): IUnixProcess;
   open(cols: number, rows: number): IUnixOpenProcess;
-  process(fd: number, pty: string): string;
-  process(pid: number): string;
+  process(fd: number, pty?: string): string;
   resize(fd: number, cols: number, rows: number): void;
 }
 

src/unix/pty.cc

@@ -58,6 +58,7 @@
 #include <paths.h>
 #include <spawn.h>
 #include <sys/event.h>
+#include <sys/sysctl.h>
 #include <termios.h>
 #endif
 
@@ -480,8 +481,8 @@ NAN_METHOD(PtyGetProc) {
     return Nan::ThrowError("Usage: pty.process(pid)");
   }
 
-  int pid = info[0]->IntegerValue(Nan::GetCurrentContext()).FromJust();
-  char *name = pty_getproc(pid);
+  int fd = info[0]->IntegerValue(Nan::GetCurrentContext()).FromJust();
+  char *name = pty_getproc(fd);
 #else
   if (info.Length() != 2 ||
       !info[0]->IsNumber() ||
@@ -692,13 +693,25 @@ pty_getproc(int fd, char *tty) {
 #elif defined(__APPLE__)
 
 static char *
-pty_getproc(int pid) {
-  char pname[MAXCOMLEN + 1];
-  if (!proc_name(pid, pname, sizeof(pname))) {
+pty_getproc(int fd) {
+  int mib[4] = { CTL_KERN, KERN_PROC, KERN_PROC_PID, 0 };
+  size_t size;
+  struct kinfo_proc kp;
+
+  if ((mib[3] = tcgetpgrp(fd)) == -1) {
+    return NULL;
+  }
+
+  size = sizeof kp;
+  if (sysctl(mib, 4, &kp, &size, NULL, 0) == -1) {
+    return NULL;
+  }
+
+  if (size != (sizeof kp) || *kp.kp_proc.p_comm == '\0') {
     return NULL;
   }
 
-  return strdup(pname);
+  return strdup(kp.kp_proc.p_comm);
 }
 
 #else

src/unixTerminal.test.ts

@@ -11,6 +11,7 @@ import * as tty from 'tty';
 import * as fs from 'fs';
 import { constants } from 'os';
 import { pollUntil } from './testUtils.test';
+import { pid } from 'process';
 
 const FIXTURES_PATH = path.normalize(path.join(__dirname, '..', 'fixtures', 'utf8-character.txt'));
 
@@ -262,6 +263,40 @@ if (process.platform !== 'win32') {
           term.on('exit', () => done());
           term.destroy();
         });
+        it('should return the name of the sub process', (done) => {
+          const data = `
+          var pty = require('./lib/index');
+          var ptyProcess = pty.spawn('zsh', ['-c', 'python3'], {
+            env: process.env
+          });
+          ptyProcess.on('data', function (data) {
+            if (ptyProcess.process === 'Python') {
+              console.log('title', ptyProcess.process);
+            }
+          });
+          setTimeout(() => null, 500);
+          console.log('ready', ptyProcess.pid);
+          `;
+          const p = cp.spawn('node', ['-e', data]);
+          let sub = '';
+          let pid = '';
+          p.stdout.on('data', (data) => {
+            if (!data.toString().indexOf('title')) {
+              sub = data.toString().split(' ')[1].slice(0, -1);
+              setTimeout(() => {
+                process.kill(parseInt(pid), 'SIGINT');
+                p.kill('SIGINT');
+              }, 200);
+            } else if (!data.toString().indexOf('ready')) {
+              pid = data.toString().split(' ')[1].slice(0, -1);
+            }
+          });
+          p.on('exit', () => {
+            assert.notStrictEqual(pid, '');
+            assert.strictEqual(sub, 'Python');
+            done();
+          });
+        });
         it('should close on exec', (done) => {
           const data = `
           var pty = require('./lib/index');

src/unixTerminal.ts

@@ -263,7 +263,8 @@ export class UnixTerminal extends Terminal {
    */
   public get process(): string {
     if (process.platform === 'darwin') {
-      return pty.process(this._pid) || this._file;
+      const title = pty.process(this._fd);
+      return (title !== 'kernel_task' ) ? title : this._file;
     }
 
     return pty.process(this._fd, this._pty) || this._file;