Add the autoreload feature. This fixes #45. I've choosen to not serve the content

via HTTP, because it's really simple to do "firefox output/index.html".

docs/getting_started.rst

@@ -127,3 +127,10 @@ And the french one::
 Despite the text quality, you can see that only the slug is the same here.
 You're not forced to define the slug that way, and it's completely possible to
 have two translations with the same title (which defines the slug)
+
+Autoreload
+==========
+
+It's possible to tell pelican to watch for your modifications, instead of
+manually launching it each time you need. Use the `-r` option, or
+`--autoreload`.

pelican/__init__.py

@@ -1,11 +1,12 @@
 import argparse
 import os
+from functools import partial
 
-from pelican.settings import read_settings
-from pelican.utils import clean_output_dir
-from pelican.writers import Writer
 from pelican.generators import (ArticlesGenerator, PagesGenerator,
-                                StaticGenerator, PdfGenerator)
+        StaticGenerator, PdfGenerator)
+from pelican.settings import read_settings
+from pelican.utils import clean_output_dir, files_changed
+from pelican.writers import Writer
 
 VERSION = "2.5.3"
 
@@ -107,7 +108,10 @@ def main():
         help='Keep the output directory and just update all the generated files.'
              'Default is to delete the output directory.')
     parser.add_argument('--version', action='version', version=VERSION,
-            help="Print the pelican version and exit")
+            help='Print the pelican version and exit')
+    parser.add_argument('-r', '--autoreload', dest='autoreload', action='store_true',
+            help="Relaunch pelican each time a modification occurs on the content"
+                 "files")
     args = parser.parse_args()
 
     # Split the markup languages only if some have been given. Otherwise, populate
@@ -125,7 +129,16 @@ def main():
         cls = getattr(module, cls_name)
 
     pelican = cls(settings, args.path, args.theme, args.output, markup, args.keep)
-    pelican.run()
+
+    if args.autoreload:
+        while True:
+            try:
+                if files_changed(pelican.path, pelican.markup):
+                    pelican.run()
+            except KeyboardInterrupt:
+                break
+    else:
+        pelican.run()
 
 
 if __name__ == '__main__':

pelican/utils.py

@@ -174,3 +174,27 @@ def process_translations(content_list):
         for a in items:
             a.translations = filter(lambda x: x != a, items)
     return index, translations
+
+
+LAST_MTIME = 0
+
+
+def files_changed(path, extensions):
+    """Return True if the files have changed since the last check"""
+
+    def with_extension(f):
+        return True if True in [f.endswith(ext) for ext in extensions] else False
+
+    def file_times(path):
+        """Return the last time files have been modified"""
+        for top_level in os.listdir(path):
+            for root, dirs, files in os.walk(top_level):
+                for file in filter(with_extension, files):
+                    yield os.stat(os.path.join(root, file)).st_mtime
+
+    global LAST_MTIME
+    mtime = max(file_times(path))
+    if mtime > LAST_MTIME:
+        LAST_MTIME = mtime
+        return True
+    return False