UX: history command

pacu/main.py

@@ -5,6 +5,7 @@
 import os
 import random
 import re
+import readline
 import shlex
 import subprocess
 import sys
@@ -16,7 +17,7 @@
 from typing import List, Optional, Any, Dict, Union, Tuple
 
 from pacu.core import lib
-from pacu.core.lib import session_dir
+from pacu.core.lib import session_dir, home_dir
 
 try:
     import jq  # type: ignore
@@ -42,6 +43,10 @@
     print('Refer to https://github.com/RhinoSecurityLabs/pacu/wiki/Installation')
     sys.exit(1)
 
+# arbitrary number, seems reasonable though
+readline.set_history_length(200)
+if os.path.isfile(f'{home_dir()}/command_history.txt') and os.access(f'{home_dir()}/command_history.txt', os.R_OK):
+    readline.read_history_file(f'{home_dir()}/command_history.txt')
 
 def load_categories() -> set:
     categories = set()
@@ -126,6 +131,7 @@ def display_pacu_help():
         swap_session <session name>         Change the active Pacu session to another one in the database
         delete_session                      Delete a Pacu session from the database. Note that the output
                                               folder for that session will not be deleted
+        history                             List the previously typed commands
 
         exit/quit                           Exit Pacu
 
@@ -179,7 +185,7 @@ class Main:
         'aws', 'data', 'exec', 'exit', 'help', 'import_keys', 'assume_role', 'list', 'load_commands_file',
         'ls', 'quit', 'regions', 'run', 'search', 'services', 'set_keys', 'set_regions',
         'swap_keys', 'update_regions', 'set_ua_suffix', 'unset_ua_suffix', 'whoami', 'swap_session', 'sessions',
-        'list_sessions', 'delete_session', 'export_keys', 'open_console', 'console'
+        'list_sessions', 'delete_session', 'export_keys', 'open_console', 'console', 'history'
     ]
 
     def __init__(self):
@@ -366,6 +372,11 @@ def get_regions(self, service, check_session=True) -> List[Optional[str]]:
         else:
             return valid_regions
 
+    def display_history(self):
+        # https://stackoverflow.com/a/7008316
+        for i in range(readline.get_current_history_length()):
+            print("{:>3}: {}".format(i+1, readline.get_history_item(i + 1)))
+
     def display_all_regions(self):
         for region in sorted(self.get_regions('all')):
             print('  {}'.format(region))
@@ -595,6 +606,8 @@ def parse_command(self, command):
             self.parse_commands_from_file(command)
         elif command[0] == 'regions':
             self.display_all_regions()
+        elif command[0] == 'history':
+            self.display_history()
         elif command[0] == 'run' or command[0] == 'exec':
             self.print_user_agent_suffix()
             self.parse_exec_module_command(command)
@@ -620,6 +633,8 @@ def parse_command(self, command):
         elif command[0] == 'whoami':
             self.print_key_info()
         elif command[0] == 'exit' or command[0] == 'quit':
+            # write out command history for loading later
+            readline.write_history_file(f'{home_dir()}/command_history.txt')
             self.exit()
         else:
             print('  Error: Unrecognized command')
@@ -1577,7 +1592,6 @@ def get_boto3_resource(
 
     def initialize_tab_completion(self) -> None:
         try:
-            import readline
             # Big thanks to samplebias: https://stackoverflow.com/a/5638688
             MODULES = []
             CATEGORIES = []