Add support for virtual 'latest' version

Fixes #8

http/template-head

@@ -18,7 +18,7 @@
 	<div id="logo">
 		<h1>Linux Cross Reference</h1>
 		<h2><a href="http://free-electrons.com">Free Electrons: Embedded Linux Experts</a></h2>
-        <p>&nbsp;&bull;&nbsp;<a href="/linux/v4.9/source">Linux</a>&nbsp;&bull;&nbsp;<a href="/u-boot/v2016.11/source">U-Boot</a>&nbsp;&bull;&nbsp;<a href="/busybox/1.26.1/source">Busybox</a>&nbsp;&bull;&nbsp;</p>
+        <p>&nbsp;&bull;&nbsp;<a href="/linux/latest/source">Linux</a>&nbsp;&bull;&nbsp;<a href="/u-boot/latest/source">U-Boot</a>&nbsp;&bull;&nbsp;<a href="/busybox/latest/source">Busybox</a>&nbsp;&bull;&nbsp;</p>
 		<p>
 		&nbsp;&bull;&nbsp;<a href="$vvar/source">source navigation</a>&nbsp;&bull;&nbsp;<a href="$vvar/ident">identifier search</a>&nbsp;&bull;&nbsp;<a href="$vvar/search">freetext search</a>&nbsp;&bull;&nbsp;<a href="http://lxr.free-electrons.com" style="color:#00FF00">Back to LXR</a>&nbsp;&bull;&nbsp;
 		</p>
@@ -26,7 +26,7 @@
 </div>
 
 <div id="topbar">
-<p>Version: $vvar $versions
+<p>Version: $vvar2 $versions
 </div>
 
 <h1>$banner</h1>

http/web.py

@@ -64,7 +64,7 @@ if m:
     if not (project and search ('^[A-Za-z0-9-]+$', project)) \
     or not (version and search ('^[A-Za-z0-9._-]+$', version)):
         status = 302
-        location = '/linux/v4.10/'+cmd+arg
+        location = '/linux/latest/'+cmd+arg
         cmd = ''
     if cmd == 'source':
         path = arg
@@ -107,14 +107,20 @@ elif status == 404:
     realprint ('Status: 404 Not Found\n')
     exit()
 
-head = open ('template-head').read()
-head = sub ('\$baseurl', 'http://' + os.environ['HTTP_HOST'] + '/' + project + '/', head)
-head = sub ('\$vvar', version, head)
-
 basedir = os.environ['LXR_PROJ_DIR']
 os.environ['LXR_DATA_DIR'] = basedir + '/' + project + '/data';
 os.environ['LXR_REPO_DIR'] = basedir + '/' + project + '/repo';
 
+if version == 'latest':
+    version2 = shell_exec ('cd ..; ./query.py latest')[0]
+else:
+    version2 = version
+
+head = open ('template-head').read()
+head = sub ('\$baseurl', 'http://' + os.environ['HTTP_HOST'] + '/' + project + '/', head)
+head = sub ('\$vvar2', version2, head)
+head = sub ('\$vvar', version, head)
+
 lines = shell_exec ('cd ..; ./query.py versions')
 va = OrderedDict()
 for l in lines:
@@ -164,13 +170,13 @@ if mode == 'source':
 
     lines = ['null - -']
     
-    type = shell_exec ('cd ..; ./query.py type '+version+' \''+path+'\'')
+    type = shell_exec ('cd ..; ./query.py type '+version2+' \''+path+'\'')
     if len (type) == 1:
         type = type[0]
         if type == 'tree':
-            lines += shell_exec ('cd ..; ./query.py dir '+version+' \''+path+'\'')
+            lines += shell_exec ('cd ..; ./query.py dir '+version2+' \''+path+'\'')
         elif type == 'blob':
-            lines += shell_exec ('cd ..; ./query.py file '+version+' \''+path+'\'')
+            lines += shell_exec ('cd ..; ./query.py file '+version2+' \''+path+'\'')
     else:
         print ('<br><b>This file does not exist.</b>')
         status = 404
@@ -247,7 +253,7 @@ elif mode == 'ident':
     head = sub ('\$title', project+' identifier search "'+ident+'" - Elixir Cross Referencer - Free Electrons', head)
     print (head, end='')
 
-    lines = shell_exec ('cd .. ; ./query.py ident '+version+" '"+ident+"'")
+    lines = shell_exec ('cd .. ; ./query.py ident '+version2+" '"+ident+"'")
     lines = iter (lines)
 
     m = search ('Defined in (\d*) file', next (lines))

query.py

@@ -39,6 +39,10 @@ if cmd == 'versions':
         if db.vers.exists (p.split(b' ')[2]):
             echo (p + b'\n')
 
+elif cmd == 'latest':
+    p = script ('get-latest')
+    echo (p)
+
 elif cmd == 'type':
     version = argv[2]
     path = argv[3]

script.sh

@@ -97,6 +97,10 @@ case $cmd in
         fi
         ;;
 
+    get-latest)
+        git tag | version_dir | grep -v '\-rc' | sort -V | tail -n 1
+        ;;
+
     get-type)
         v=`echo $1 | version_rev`
         git cat-file -t "$v:`denormalize $2`" 2>/dev/null