Closes #85 and #30, add exec feature, edit check

Add help menus and help command
Add exec feature to be kinda msfconsole-y
Edit check behavior to be a little clearer/more logical

routersploit/interpreter.py

@@ -3,6 +3,7 @@
 import sys
 import traceback
 import atexit
+from subprocess import call
 
 from routersploit.exceptions import RoutersploitException
 from routersploit import utils
@@ -16,6 +17,8 @@
 class BaseInterpreter(object):
     history_file = os.path.expanduser("~/.history")
     history_length = 100
+    global_help = ""
+
 
     def __init__(self):
         self.setup()
@@ -146,6 +149,18 @@ def suggested_commands(self):
 
 class RoutersploitInterpreter(BaseInterpreter):
     history_file = os.path.expanduser("~/.rsf_history")
+    global_help = """Global commands:
+    help                        Print this help menu
+    use <module>                Select a module for usage
+    exec <shell command> <args> Execute a command in a shell
+    exit                        Exit RouterSploit"""
+
+    module_help = """Module commands:
+    run                                 Run the selected module with the given options
+    back                                De-select the current module
+    set <option name>=<option value>    Set an option for the selected module
+    show [info|options|devices]         Print information, options, or target devices for a module
+    check                               Check if a given target is vulnerable to a selected module's exploit"""
 
     def __init__(self):
         super(RoutersploitInterpreter, self).__init__()
@@ -231,9 +246,9 @@ def suggested_commands(self):
         :return: list of most accurate command suggestions
         """
         if self.current_module:
-            return ['run', 'back', 'set ', 'show ', 'check', 'exit']
+            return ['run', 'back', 'set ', 'show ', 'check', 'exec', 'help', 'exit']
         else:
-            return ['use ', 'exit']
+            return ['use ', 'exec', 'help', 'exit']
 
     def command_back(self, *args, **kwargs):
         self.current_module = None
@@ -349,6 +364,11 @@ def complete_show(self, text, *args, **kwargs):
 
     @utils.module_required
     def command_check(self, *args, **kwargs):
+        if self.current_module.check() == None:
+            return
+        if not self.current_module.target:
+            utils.print_error("No target set")
+            return
         try:
             result = self.current_module.check()
         except:
@@ -361,5 +381,14 @@ def command_check(self, *args, **kwargs):
             else:
                 utils.print_status("Target could not be verified")
 
+    def command_help(self, *args, **kwargs):
+        print(self.global_help)
+        if self.current_module:
+            print()
+            print(self.module_help)
+
+    def command_exec(self, *args, **kwargs):
+        call(' '.join(args))
+
     def command_exit(self, *args, **kwargs):
         raise KeyboardInterrupt