1 files changed, 67 insertions, 3 deletions

diff --git a/src/luarocks/list.lua b/src/luarocks/list.lua
index 319909d..fddded0 100644
--- a/src/luarocks/list.lua
+++ b/src/luarocks/list.lua
@@ -6,33 +6,97 @@ local list = {}
 package.loaded["luarocks.list"] = list
 
 local search = require("luarocks.search")
+local deps = require("luarocks.deps")
 local cfg = require("luarocks.cfg")
 local util = require("luarocks.util")
 local path = require("luarocks.path")
 
-list.help_summary = "Lists currently installed rocks."
+list.help_summary = "List currently installed rocks."
 list.help_arguments = "[--porcelain] <filter>"
 list.help = [[
 <filter> is a substring of a rock name to filter by.
 
+--outdated    List only rocks for which there is a
+              higher version available in the rocks server.
+
 --porcelain   Produce machine-friendly output.
 ]]
 
+local function check_outdated(trees, query)
+   local results_installed = {}
+   for _, tree in ipairs(trees) do
+      search.manifest_search(results_installed, path.rocks_dir(tree), query)
+   end
+   local outdated = {}
+   for name, versions in util.sortedpairs(results_installed) do
+      local latest_installed
+      local latest_available, latest_available_repo
+
+      for version, _ in util.sortedpairs(versions) do
+         latest_installed = version
+         break
+      end
+
+      local query_available = search.make_query(name:lower())
+      query.exact_name = true
+      local results_available, err = search.search_repos(query_available)
+      
+      if results_available[name] then
+         for version, repos in util.sortedpairs(results_available[name], deps.compare_versions) do
+            latest_available = version
+            for _, repo in ipairs(repos) do
+               latest_available_repo = repo.repo
+               break
+            end
+            break
+         end
+         
+         if deps.compare_versions(latest_available, latest_installed) then
+            table.insert(outdated, { name = name, installed = latest_installed, available = latest_available, repo = latest_available_repo })
+         end
+      end
+   end
+   return outdated
+end
+
+local function list_outdated(trees, query, porcelain)
+   util.title("Outdated rocks:", porcelain)
+   local outdated = check_outdated(trees, query)
+   for _, item in ipairs(outdated) do
+      if porcelain then
+         util.printout(item.name, item.installed, item.available, item.repo)
+      else
+         util.printout(item.name)
+         util.printout("   "..item.installed.." < "..item.available.." at "..item.repo)
+         util.printout()
+      end
+   end
+   return true
+end
+
 --- Driver function for "list" command.
 -- @param filter string or nil: A substring of a rock name to filter by.
 -- @param version string or nil: a version may also be passed.
 -- @return boolean: True if succeeded, nil on errors.
 function list.run(...)
    local flags, filter, version = util.parse_flags(...)
-   local results = {}
    local query = search.make_query(filter and filter:lower() or "", version)
    query.exact_name = false
    local trees = cfg.rocks_trees
    if flags["tree"] then
       trees = { flags["tree"] }
    end
+   
+   if flags["outdated"] then
+      return list_outdated(trees, query, flags["porcelain"])
+   end
+   
+   local results = {}
    for _, tree in ipairs(trees) do
-      search.manifest_search(results, path.rocks_dir(tree), query)
+      local ok, err = search.manifest_search(results, path.rocks_dir(tree), query)
+      if not ok then
+         util.warning(err)
+      end
    end
    util.title("Installed rocks:", flags["porcelain"])
    search.print_results(results, flags["porcelain"])