Check that all images are used (lint.py)

This caught a markup error, an unused image, and case-sensitivity (which
Sphinx doesn't mind, but still).  Now a standard test function.

chapters/chap01-setup-starting.rst

@@ -52,7 +52,7 @@ movie. Well done! I can tell you’ll go far! Next step is to hit
 :kbd:`Enter` on :guilabel:`Continue Playing`, which should be
 highlighted. You’ll then be presented with this screen.
 
-.. image: images/01-save-list.png
+.. image:: images/01-save-list.png
    :align: center
 
 This is the save game list, which gets cluttered very quickly as

misc/lint.py

@@ -4,6 +4,7 @@
 Any other automatic checks should be in this file too.
 """
 
+from glob import glob
 from io import open
 import os
 from os.path import *
@@ -40,11 +41,34 @@ def lint(path):
     if failed:
         print('Use your text editor to convert tabs to spaces, wrap lines '
               'or trim trailing whitespace with minimal effort.')
-        sys.exit(failed)
-    print('All files are OK')
+    return failed
+
+
+def unused_images(path):
+    """Check that all files in image subdirs are references in the text."""
+    print('Checking for unused images...')
+    failed = False
+    dirs = ['chapters', 'tutorials']
+    for d in dirs:
+        text = ''
+        for fname in glob(os.path.join(d, '*.rst')):
+            with open(fname, encoding='utf-8') as f:
+                text += f.read()
+        for img in glob(os.path.join(d, 'images', '*.*')):
+            img = os.path.basename(img)
+            if img == 'Thumbs.db':
+                continue
+            markup = '.. image:: images/{}'.format(img)
+            if markup not in text:
+                failed = True
+                print('Error:  image not referenced, {}/{}/{}'.format(
+                      d, 'images', img))
+    if failed:
+        print('Use or or delete these images.')
+    return failed
 
 
 if __name__ == '__main__':
     # lint everything in the parent directory, wherever the script is run from.
     p = relpath(join(dirname(__file__), '..'))
-    lint(p)
+    sys.exit(lint(p) or unused_images(p))

tutorials/custom-embarks.rst

@@ -16,7 +16,7 @@ now is selecting :guilabel:`Prepare for your journey carefully` from
 the embark menu. You will now be presented with your list of dwarfs
 and the skills they can access.
 
-.. image:: images/14_Dwarf_Fortress_Embark_01.png
+.. image:: images/14_dwarf_fortress_embark_01.png
    :align: center
 
 Have a fiddle with your controls. The left-right arrows move between
@@ -52,7 +52,7 @@ When you’re done, (you may have to hit :kbd:`Esc` to head back out of
 the menu), hit :kbd:`Tab` to go to the item list. Many items will be
 on your list already, on the left, with animal options on the right.
 
-.. image:: images/14_Dwarf_Fortress_Embark_02.png
+.. image:: images/14_dwarf_fortress_embark_02.png
    :align: center
 
 As in the last menu, use the arrows to move left and right and the up
@@ -70,7 +70,7 @@ for the rest of the items, that depends on your strategy. For now, hit
 :kbd:`n` for :guilabel:`New`. You’ll be taken to a huge menu of
 purchasable items.
 
-.. image:: images/14_Dwarf_Fortress_Embark_03.png
+.. image:: images/14_dwarf_fortress_embark_03.png
    :align: center
 
 Lets add some turtles to the list of stuff we’re going to take. Scroll
@@ -88,7 +88,7 @@ only one option, :guilabel:`Dwarven Wine`. You’ll note that the
 :guilabel:`Drinks` part of the menu is highlighted, you’ll need scroll
 across :guilabel:`Dwarven Wine`, then hit :kbd:`Enter`.
 
-.. image:: images/14_Dwarf_Fortress_Embark_04.png
+.. image:: images/14_dwarf_fortress_embark_04.png
    :align: center
 
 You can now increase and decrease the number in the usual fashion.