man: use lxml for faster generation and pretty printing

README

@@ -116,6 +116,7 @@ REQUIREMENTS:
         gtkdocize (optional)
         python (optional)
         sphinx (optional)
+        python-lxml (entirely optional)
 
         When systemd-hostnamed is used it is strongly recommended to
         install nss-myhostname to ensure that in a world of

make-directive-index.py

@@ -19,7 +19,12 @@
 
 import sys
 import collections
-import xml.etree.ElementTree as tree
+try:
+    from lxml import etree as tree
+    PRETTY = dict(pretty_print=True)
+except ImportError:
+    import xml.etree.ElementTree as tree
+    PRETTY = {}
 import re
 
 TEMPLATE = '''\
@@ -277,4 +282,4 @@ def make_page(*xml_files):
     return _make_page(template, directive_groups, formatting)
 
 if __name__ == '__main__':
-    tree.dump(make_page(*sys.argv[1:]))
+    tree.dump(make_page(*sys.argv[1:]), **PRETTY)

make-man-index.py

@@ -19,7 +19,12 @@
 #  along with systemd; If not, see <http://www.gnu.org/licenses/>.
 
 import collections
-import xml.etree.ElementTree as tree
+try:
+    from lxml import etree as tree
+    PRETTY = dict(pretty_print=True)
+except ImportError:
+    import xml.etree.ElementTree as tree
+    PRETTY = {}
 import sys
 import re
 MDASH = ' — ' if sys.version_info.major >= 3 else ' -- '
@@ -130,4 +135,4 @@ def make_page(xml_files):
     return template
 
 if __name__ == '__main__':
-    tree.dump(make_page(sys.argv[1:]))
+    tree.dump(make_page(sys.argv[1:]), **PRETTY)