Initial commit

shell.py

@@ -0,0 +1,106 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+#
+#  gameshell.py
+#  
+#  Copyright 2018 chees <chees@DESKTOP-0CA7MCF>
+#  
+#  This program is free software; you can redistribute it and/or modify
+#  it under the terms of the GNU General Public License as published by
+#  the Free Software Foundation; either version 2 of the License, or
+#  (at your option) any later version.
+#  
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#  
+#  You should have received a copy of the GNU General Public License
+#  along with this program; if not, write to the Free Software
+#  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+#  MA 02110-1301, USA.
+#  
+#  Ver. 0.1.0017
+
+
+import types as _types
+import traceback as _tb
+
+class Shell(object):
+    
+    def __init__(self):
+        self.__commands = {'exit': self.exitShell}
+        self.__aliases = {}
+        self.ps1 = '> '
+        self.ps2 = '> '
+        self.__exit = False
+        
+    def run(self):
+        """The main game/shell loop"""
+        while not self.__exit:
+            print(self.ps1, end = '')
+            command = self.scanInput()
+            # we have to handle shell built-ins first (when we get some)
+            if len(command) == 0:
+                continue
+            if command[0] in self.__commands:
+                try:
+                    self.__commands[command[0]](command[1:])
+                except Exception as e:
+                    _tb.print_exc()
+                    print(e)
+            else:
+                self.handleUnknownCommand(command)
+            self.update()
+            
+    def man(self, args):
+        help(self.__commands[args[0]])
+                
+    def registerCommand(self, commandName: str, command: _types.FunctionType):
+        """command must be a function that takes one argument: a list of strings,
+conventionally called args or argv"""
+        self.__commands[commandName] = command
+        
+    def registerAlias(self, a: str, original: list):
+        """makes 'a' an alias for original.
+'a' must be one token, but original can be multiple."""
+        self.__aliases[a] = original
+        
+    def getAlias(self, a: str):
+        if a in self.__aliases:
+            return self.__aliases[a]
+        else:
+            return None
+        
+    def exitShell(self, args):
+        """The default exit command."""
+        self.__exit = True
+        
+    # Beyond this point are functions that are called within the main loop.
+    def scanInput(self):
+        """Parses input. Override this for custom input parsing, or input source."""
+        ret = input()
+        if ret == '':
+            return []
+        ret = ret.split()
+        a = self.getAlias(ret[0])
+        if a:
+            ret = a[:] + ret[1:]
+        return ret
+        
+    def handleUnknownCommand(self, command):
+        """Handle commands that aren't registered. Override this if you want to do
+something with those commands."""
+        print("Bad command.")
+        
+    def update(self):
+        """Runs at the end of each loop. Does nothing by default. Override this if
+there is something you want the shell to do between every command."""
+        pass
+
+def main(args):
+    return 0
+
+if __name__ == '__main__':
+    import sys
+    sys.exit(main(sys.argv))