Add '-m mod : run library module as a script' option.

Closes gh-1350.

IPython/core/interactiveshell.py

@@ -26,6 +26,7 b' import codeop'
 import inspect
 import os
 import re
+import runpy
 import sys
 import tempfile
 import types
@@ -2356,6 +2357,28 b' class InteractiveShell(SingletonConfigurable, Magic):'
                 self.showtraceback()
                 warn('Unknown failure executing file: <%s>' % fname)
 
+    def safe_run_module(self, mod_name, where):
+        """A safe version of runpy.run_module().
+
+        This version will never throw an exception, but instead print
+        helpful error messages to the screen.
+
+        Parameters
+        ----------
+        mod_name : string
+            The name of the module to be executed.
+        where : dict
+            The globals namespace.
+        """
+        try:
+            where.update(
+                runpy.run_module(str(mod_name), run_name="__main__",
+                                 alter_sys=True)
+                )
+        except:
+            self.showtraceback()
+            warn('Unknown failure executing module: <%s>' % mod_name)
+
     def run_cell(self, raw_cell, store_history=False):
         """Run a complete IPython cell.
 

IPython/core/shellapp.py

@@ -103,6 +103,7 b' shell_aliases = dict('
     logfile='InteractiveShell.logfile',
     logappend='InteractiveShell.logappend',
     c='InteractiveShellApp.code_to_run',
+    m='InteractiveShellApp.module_to_run',
     ext='InteractiveShellApp.extra_extension',
 )
 shell_aliases['cache-size'] = 'InteractiveShell.cache_size'
@@ -146,6 +147,9 b' class InteractiveShellApp(Configurable):'
     code_to_run = Unicode('', config=True,
         help="Execute the given command string."
     )
+    module_to_run = Unicode('', config=True,
+        help="Run the module as a script."
+    )
     pylab_import_all = Bool(True, config=True,
         help="""If true, an 'import *' is done from numpy and pylab,
         when using pylab"""
@@ -183,6 +187,7 b' class InteractiveShellApp(Configurable):'
         self._run_exec_lines()
         self._run_exec_files()
         self._run_cmd_line_code()
+        self._run_module()
         
         # flush output, so itwon't be attached to the first cell
         sys.stdout.flush()
@@ -294,3 +299,7 b' class InteractiveShellApp(Configurable):'
                               fname)
                 self.shell.showtraceback()
 
+    def _run_module(self):
+        """Run module specified at the command-line."""
+        if self.module_to_run:
+            self.shell.safe_run_module(self.module_to_run, self.shell.user_ns)