Docs - add canonical url to html doc pages.

doc/html/header.txt

@@ -6,6 +6,8 @@
 
 	<title>Slurm Workload Manager</title>
 
+	<!--#canonical-->
+
 	<link rel="shortcut icon" href="favicon.ico" />
 
 	<link rel="stylesheet" type="text/css" href="fonts.css" />

doc/html/shtml2html.py

@@ -5,9 +5,14 @@ import sys
 import os
 import codecs
 
+canonical_url = 'https://slurm.schedmd.com/'
+
 include_pat = r'(<!--\s*#include\s*virtual\s*=\s*"([^"]+)"\s*-->)'
 include_regex = re.compile(include_pat)
 
+canonical_pat = r'(<!--\s*#canonical\s*-->)'
+canonical_regex = re.compile(canonical_pat)
+
 url_pat = r'(\s+href\s*=\s*")([^"#]+)(#[^"]+)?(")'
 url_regex = re.compile(url_pat)
 
@@ -15,6 +20,7 @@ version_pat = r'(@SLURM_VERSION@)'
 version_regex = re.compile(version_pat)
 
 dirname = ''
+newfilename = ''
 
 def include_virtual(matchobj):
     global dirname
@@ -30,6 +36,10 @@ def include_virtual(matchobj):
     else:
         return matchobj.group(0)
 
+def canonical_rewrite(matchobj):
+    global newfilename
+    return '<link rel="canonical" href="' + canonical_url + newfilename + '" />'
+
 def url_rewrite(matchobj):
     global dirname
     if dirname:
@@ -73,6 +83,7 @@ for filename in files:
     for line in shtml.readlines():
         line = include_regex.sub(include_virtual, line)
         line = version_regex.sub(version_rewrite, line)
+        line = canonical_regex.sub(canonical_rewrite, line)
         line = url_regex.sub(url_rewrite, line)
         html.write(line)