rename

login-log.py

@@ -1,4 +1,5 @@
-#!/usr/bin/env python3
+# #!/usr/bin/env python3
+"""Write information into a logfile, like the timestamp and the hostname."""
 
 import os
 import socket
@@ -18,7 +19,7 @@ else:
 
 # Create the file if it does not exist yet
 if not os.path.exists(logfile):
-    with open(logfile, 'w'):
+    with open(logfile, 'w', encoding="utf-8"):
         pass
 
 # Determine the current date and time
@@ -30,36 +31,49 @@ current_day = today.strftime("%d.%m.%Y")
 current_time = now.strftime("%H:%M:%S")
 
 # Determine the client hostname
-client_hostname = os.getenv("CLIENTNAME")
+CLIENT_HOSTNAME = os.getenv("CLIENTNAME")
 
 # Determine the client hostname via a different method
 # in case the first one failed
-if client_hostname is None:
+if CLIENT_HOSTNAME is None:
-    client_hostname = socket.gethostbyaddr(socket.gethostname())[0]
+    try:
+        CLIENT_HOSTNAME = socket.gethostbyaddr(socket.gethostname())[0]
+    except socket.herror:
+        print("Socket host error: unable to determine hostname.")
+        CLIENT_HOSTNAME = "localhost"
 
 
-# Class for prepending the information to the log file
+# The `class Prepender` is a class that is used to prepend information to the
-class Prepender(object):
+# top of a log file. It takes the file path as an argument and reads in the
+# existing file. It provides methods to write lines to the file in reverse
+# order, effectively prepending the lines to the top of the file. Finally,
+# when the `Prepender` object is closed or exited, it writes the modified lines
+# back to the file.
+class Prepender:
+    '''Class for prepending the information to the log file.'''
     def __init__(self,
                  file_path,
                  ):
         # Read in the existing file, so we can write it back later
-        with open(file_path, mode='r') as f:
+        with open(file_path, mode='r', encoding="utf-8") as file:
-            self.__write_queue = f.readlines()
+            self.__write_queue = file.readlines()
 
-        self.__open_file = open(file_path, mode='w')
+        self.__open_file = open(file_path, mode='w', encoding="utf-8")
 
     def write_line(self, line):
+        '''Function for adding a new line to the file.'''
         self.__write_queue.insert(0,
                                   "%s\n" % line,
                                   )
 
     def write_lines(self, lines):
+        '''Function for adding new lines to the file.'''
         lines.reverse()
         for line in lines:
             self.write_line(line)
 
     def close(self):
+        '''Function for closing the file after use.'''
         self.__exit__(None, None, None)
 
     def __enter__(self):
@@ -70,11 +84,15 @@ class Prepender(object):
             self.__open_file.writelines(self.__write_queue)
         self.__open_file.close()
 
+    # if isinstance(CLIENT_HOSTNAME, type) is None:
+    # if CLIENT_HOSTNAME == "None":
+    # CLIENT_HOSTNAME = "localhost"
+
 
 # Prepend the determined information to the top of the log file
 with Prepender(logfile) as f:
     # Must write individual lines in reverse order
-    f.write_line(current_day+' - '+current_time+' - '+client_hostname)
+    f.write_line(current_day+' - '+current_time+' - '+CLIENT_HOSTNAME)
 
 # Or, use write_lines instead - that maintains order.
 # with Prepender(logfile) as f: