child_process: add shell option to spawn()

This commit adds a shell option, to spawn() and spawnSync(). This
option allows child processes to be spawned with or without a
shell. The option also allows a custom shell to be defined, for
compatibility with exec()'s shell option.

Fixes: https://github.com/nodejs/node/issues/1009
PR-URL: https://github.com/nodejs/node/pull/4598
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: James M Snell <jasnell@gmail.com>

1 files changed, 29 insertions, 24 deletions

diff --git a/lib/child_process.js b/lib/child_process.js
index ee73562d24..e682aed5ae 100644
--- a/lib/child_process.js
+++ b/lib/child_process.js
@@ -71,7 +71,8 @@ exports._forkChild = function(fd) {
 
 
 function normalizeExecArgs(command /*, options, callback*/) {
-  var file, args, options, callback;
+  let options;
+  let callback;
 
   if (typeof arguments[1] === 'function') {
     options = undefined;
@@ -81,25 +82,12 @@ function normalizeExecArgs(command /*, options, callback*/) {
     callback = arguments[2];
   }
 
-  if (process.platform === 'win32') {
-    file = process.env.comspec || 'cmd.exe';
-    args = ['/s', '/c', '"' + command + '"'];
-    // Make a shallow copy before patching so we don't clobber the user's
-    // options object.
-    options = util._extend({}, options);
-    options.windowsVerbatimArguments = true;
-  } else {
-    file = '/bin/sh';
-    args = ['-c', command];
-  }
-
-  if (options && options.shell)
-    file = options.shell;
+  // Make a shallow copy so we don't clobber the user's options object.
+  options = Object.assign({}, options);
+  options.shell = typeof options.shell === 'string' ? options.shell : true;
 
   return {
-    cmd: command,
-    file: file,
-    args: args,
+    file: command,
     options: options,
     callback: callback
   };
@@ -109,7 +97,6 @@ function normalizeExecArgs(command /*, options, callback*/) {
 exports.exec = function(command /*, options, callback*/) {
   var opts = normalizeExecArgs.apply(null, arguments);
   return exports.execFile(opts.file,
-                          opts.args,
                           opts.options,
                           opts.callback);
 };
@@ -123,7 +110,8 @@ exports.execFile = function(file /*, args, options, callback*/) {
     maxBuffer: 200 * 1024,
     killSignal: 'SIGTERM',
     cwd: null,
-    env: null
+    env: null,
+    shell: false
   };
 
   // Parse the optional positional parameters.
@@ -153,6 +141,7 @@ exports.execFile = function(file /*, args, options, callback*/) {
     env: options.env,
     gid: options.gid,
     uid: options.uid,
+    shell: options.shell,
     windowsVerbatimArguments: !!options.windowsVerbatimArguments
   });
 
@@ -331,7 +320,23 @@ function normalizeSpawnArguments(file /*, args, options*/) {
   else if (options === null || typeof options !== 'object')
     throw new TypeError('"options" argument must be an object');
 
-  options = util._extend({}, options);
+  // Make a shallow copy so we don't clobber the user's options object.
+  options = Object.assign({}, options);
+
+  if (options.shell) {
+    const command = [file].concat(args).join(' ');
+
+    if (process.platform === 'win32') {
+      file = typeof options.shell === 'string' ? options.shell :
+              process.env.comspec || 'cmd.exe';
+      args = ['/s', '/c', '"' + command + '"'];
+      options.windowsVerbatimArguments = true;
+    } else {
+      file = typeof options.shell === 'string' ? options.shell : '/bin/sh';
+      args = ['-c', command];
+    }
+  }
+
   args.unshift(file);
 
   var env = options.env || process.env;
@@ -491,12 +496,12 @@ function execFileSync(/*command, args, options*/) {
 exports.execFileSync = execFileSync;
 
 
-function execSync(/*command, options*/) {
+function execSync(command /*, options*/) {
   var opts = normalizeExecArgs.apply(null, arguments);
   var inheritStderr = opts.options ? !opts.options.stdio : true;
 
-  var ret = spawnSync(opts.file, opts.args, opts.options);
-  ret.cmd = opts.cmd;
+  var ret = spawnSync(opts.file, opts.options);
+  ret.cmd = command;
 
   if (inheritStderr)
     process.stderr.write(ret.stderr);