diff --git a/src/beautifiers/beautifier.coffee b/src/beautifiers/beautifier.coffee
index be01137..cb3845c 100644
--- a/src/beautifiers/beautifier.coffee
+++ b/src/beautifiers/beautifier.coffee
@@ -113,7 +113,7 @@ module.exports = class Beautifier
   _envCacheDate: null
   _envCacheExpiry: 10000 # 10 seconds
   getShellEnvironment: ->
-    return new @Promise((resolve, reject) =>
+    return new Promise((resolve, reject) =>
       # Check Cache
       if @_envCache? and @_envCacheDate?
         # Check if Cache is old
@@ -248,72 +248,79 @@ module.exports = class Beautifier
   ###
   Run command-line interface command
   ###
-  run: (executable, args, {ignoreReturnCode, help} = {}) ->
+  run: (executable, args, {cwd, ignoreReturnCode, help, onStdin} = {}) ->
     # Flatten args first
     args = _.flatten(args)
+
     # Resolve executable and all args
     Promise.all([executable, Promise.all(args)])
-    .then(([exeName, args]) =>
-      @debug('exeName, args:', exeName, args)
-      return new Promise((resolve, reject) =>
+      .then(([exeName, args]) =>
+        @debug('exeName, args:', exeName, args)
+
         # Remove undefined/null values
         args = _.without(args, undefined)
         args = _.without(args, null)
+
         # Get PATH and other environment variables
-        Promise.all([@getShellEnvironment(), @which(exeName)])
-        .then(([env, exePath]) =>
-          @debug('exePath, env:', exePath, env)
-          exe = exePath ? exeName
-          # Spawn command
-          options = {
-            env: env
-          }
-          cmd = @spawn(exe, args, options)
-            .then(({returnCode, stdout, stderr}) =>
-              @verbose('spawn result', returnCode, stdout, stderr)
-              # If return code is not 0 then error occured
-              if not ignoreReturnCode and returnCode isnt 0
-                err = new Error(stderr)
-                windowsProgramNotFoundMsg = "is not recognized as an \
-                internal or external command" # operable program or batch file
-                @verbose(stderr, windowsProgramNotFoundMsg)
-                if @isWindows and returnCode is 1 and \
-                stderr.indexOf(windowsProgramNotFoundMsg) isnt -1
-                  err = @commandNotFoundError(exeName, help)
-                reject(err)
-              else
-                resolve(stdout)
-            )
-            .catch((err) =>
-              @debug('error', err)
-              # Check if error is ENOENT
-              # (command could not be found)
-              if err.code is 'ENOENT' or err.errno is 'ENOENT'
-                reject(@commandNotFoundError(exeName, help))
-              else
-                # continue as normal error
-                reject(err)
-            )
-        )
+        Promise.all([exeName, @getShellEnvironment(), @which(exeName)])
+      )
+      .then(([exeName, env, exePath]) =>
+        @debug('exePath, env:', exePath, env)
+
+        exe = exePath ? exeName
+        options = {
+          cwd: cwd
+          env: env
+        }
+
+        @spawn(exe, args, options, onStdin)
+          .then(({returnCode, stdout, stderr}) =>
+            @verbose('spawn result', returnCode, stdout, stderr)
+
+            # If return code is not 0 then error occured
+            if not ignoreReturnCode and returnCode isnt 0
+              # operable program or batch file
+              windowsProgramNotFoundMsg = "is not recognized as an internal or external command"
+
+              @verbose(stderr, windowsProgramNotFoundMsg)
+
+              if @isWindows and returnCode is 1 and stderr.indexOf(windowsProgramNotFoundMsg) isnt -1
+                throw @commandNotFoundError(exeName, help)
+              else
+                throw new Error(stderr)
+            else
+              stdout
+          )
+          .catch((err) =>
+            @debug('error', err)
+
+            # Check if error is ENOENT (command could not be found)
+            if err.code is 'ENOENT' or err.errno is 'ENOENT'
+              throw @commandNotFoundError(exeName, help)
+            else
+              # continue as normal error
+              throw err
+          )
       )
-    )
 
   ###
   Spawn
   ###
-  spawn: (exe, args, options) ->
+  spawn: (exe, args, options, onStdin) ->
     return new Promise((resolve, reject) =>
       @debug('spawn', exe, args)
+
       cmd = spawn(exe, args, options)
-      # add a 'data' event listener for the spawn instance
       stdout = ""
       stderr = ""
-      cmd.stdout.on('data', (data) -> stdout += data )
-      cmd.stderr.on('data', (data) -> stderr += data )
-      # when the spawn child process exits,
-      # check if there were any errors and
-      # close the writeable stream
-      cmd.on('exit', (returnCode) =>
+
+      cmd.stdout.on('data', (data) ->
+        stdout += data
+      )
+      cmd.stderr.on('data', (data) ->
+        stderr += data
+      )
+      cmd.on('close', (returnCode) =>
         @debug('spawn done', returnCode, stderr, stdout)
         resolve({returnCode, stdout, stderr})
       )
@@ -321,6 +328,8 @@ module.exports = class Beautifier
         @debug('error', err)
         reject(err)
       )
+
+      onStdin cmd.stdin if onStdin
     )
 
   ###
diff --git a/src/beautifiers/clang-format.coffee b/src/beautifiers/clang-format.coffee
index 4b129ba..bb03abf 100644
--- a/src/beautifiers/clang-format.coffee
+++ b/src/beautifiers/clang-format.coffee
@@ -21,7 +21,7 @@ module.exports = class ClangFormat extends Beautifier
     Dump contents to a given file
   ###
   dumpToFile: (name = "atom-beautify-dump", contents = "") ->
-    return new Promise((resolve, reject) =>
+    return new @Promise((resolve, reject) =>
       fs.open(name, "w", (err, fd) =>
         @debug('dumpToFile', name, err, fd)
         return reject(err) if err
diff --git a/src/beautifiers/rustfmt.coffee b/src/beautifiers/rustfmt.coffee
index 480ab4f..88f3ad5 100644
--- a/src/beautifiers/rustfmt.coffee
+++ b/src/beautifiers/rustfmt.coffee
@@ -4,34 +4,47 @@ Requires https://github.com/nrc/rustfmt
 
 "use strict"
 Beautifier = require('./beautifier')
+path = require('path')
+
+versionCheckState = false
 
 module.exports = class Rustfmt extends Beautifier
-
   name: "rustfmt"
 
   options: {
     Rust: true
   }
 
-  beautify: (text, language, options) ->
-
-    # get file path which is the search path for rustfmt.toml as
-    # the beautifier runs rustfmt in a tmp directory.
-    # This will pick up any rustfmt.toml defined in the crate root
-
-    editor = atom.workspace.getActivePaneItem()
-    file = editor?.buffer.file
-    filePath = file?.path
+  beautify: (text, language, options, context) ->
+    cwd = context.filePath and path.dirname context.filePath
     program = options.rustfmt_path or "rustfmt"
-    @run(program, [
-      tmpFile = @tempFile("tmp", text)
-      ["--write-mode", "overwrite"]
-      ["--config-path", filePath]
-      ], help: {
-        link: "https://github.com/nrc/rustfmt"
-        program: "rustfmt"
-        pathOption: "Rust - Rustfmt Path"
+    help = {
+      link: "https://github.com/nrc/rustfmt"
+      program: "rustfmt"
+      pathOption: "Rust - Rustfmt Path"
+    }
+
+    # 0.5.0 is a relatively new version at the point of writing,
+    # but is essential for this to work with stdin.
+    # => Check for it specifically.
+    p = if versionCheckState == program
+      @Promise.resolve()
+    else
+      @run(program, ["--version"], help: help)
+        .then((stdout) ->
+          if /^0\.(?:[0-4]\.[0-9])/.test(stdout.trim())
+            versionCheckState = false
+            throw new Error("rustfmt version 0.5.0 or newer required")
+          else
+            versionCheckState = program
+            undefined
+        )
+
+    p.then(=>
+      @run(program, [], {
+        cwd: cwd
+        help: help
+        onStdin: (stdin) ->
+          stdin.end text
       })
-      .then(=>
-        @readFile(tmpFile)
-      )
+    )