Merge pull request #503 from ankitpati/minimise-hosts-file

Add Option to Minimise hosts File

readme_template.md

@@ -109,6 +109,11 @@ ignoring non-necessary lines (empty lines and comments) and putting multiple
 domains in each line. Reducing the number of lines of the hosts file improves 
 the performances under Windows (with DNS Client service enabled).
 
+`--minimise`, or `-m`: `false` (default) or `true`, like `--compress`, but puts
+each domain on a separate line. This is necessary because many implementations
+of URL blockers that rely on `hosts` files do not conform to the standard which
+allows multiple hosts on a single line.
+
 ## How do I control which sources are unified?
 
 Add one or more  *additional* sources, each in a subfolder of the `data/`

testUpdateHostsFile.py

@@ -101,6 +101,7 @@ class TestGetDefaults(Base):
                         "extensionspath": "foo" + self.sep + "extensions",
                         "extensions": [],
                         "compress": False,
+                        "minimise": False,
                         "outputsubfolder": "",
                         "hostfilename": "hosts",
                         "targetip": "0.0.0.0",

updateHostsFile.py

@@ -63,6 +63,7 @@ def get_defaults():
         "extensionspath": path_join_robust(BASEDIR_PATH, "extensions"),
         "extensions": [],
         "compress": False,
+        "minimise": False,
         "outputsubfolder": "",
         "hostfilename": "hosts",
         "targetip": "0.0.0.0",
@@ -126,6 +127,11 @@ def main():
                              "putting multiple domains in "
                              "each line. Improve the "
                              "performances under Windows.")
+    parser.add_argument("--minimise", "-m", dest="minimise",
+                        default=False, action="store_true",
+                        help="Minimise the hosts file "
+                             "ignoring non-necessary lines "
+                             "(empty lines and comments).")
 
     global settings
 
@@ -186,6 +192,12 @@ def main():
         compressed_file = tempfile.NamedTemporaryFile()
         remove_dups_and_excl(merge_file, exclusion_regexes, compressed_file)
         compress_file(compressed_file, settings["targetip"], final_file)
+    elif settings["minimise"]:
+        final_file = open(path_join_robust(settings["outputpath"], "hosts"),
+                          "w+b" if PY3 else "w+")
+        minimised_file = tempfile.NamedTemporaryFile()
+        remove_dups_and_excl(merge_file, exclusion_regexes, minimised_file)
+        minimise_file(minimised_file, settings["targetip"], final_file)
     else:
         final_file = remove_dups_and_excl(merge_file, exclusion_regexes)
 
@@ -688,6 +700,37 @@ def compress_file(input_file, target_ip, output_file):
     input_file.close()
 
 
+def minimise_file(input_file, target_ip, output_file):
+    """
+    Reduce the file dimension removing non-necessary lines (empty lines and
+    comments).
+
+    Parameters
+    ----------
+    input_file : file
+        The file object that contains the hostnames that we are reducing.
+    target_ip : str
+        The target IP address.
+    output_file : file
+        The file object that will contain the reduced hostnames.
+    """
+
+    input_file.seek(0)  # reset file pointer
+    write_data(output_file, '\n')
+
+    lines = []
+    for line in input_file.readlines():
+        line = line.decode("UTF-8")
+
+        if line.startswith(target_ip):
+            lines.append(line[:line.find('#')].strip() + '\n')
+
+    for line in lines:
+        write_data(output_file, line)
+
+    input_file.close()
+
+
 def remove_dups_and_excl(merge_file, exclusion_regexes, output_file=None):
     """
     Remove duplicates and remove hosts that we are excluding.