Per-command usage messages.

1 files changed, 20 insertions, 1 deletions

diff --git a/Usage.hs b/Usage.hs
index 32d8b2829..a9c8fa7f2 100644
--- a/Usage.hs
+++ b/Usage.hs
@@ -11,9 +11,14 @@ import Common.Annex
 
 import Types.Command
 
+import System.Console.GetOpt
+
+usageMessage :: String -> String
+usageMessage s = "Usage: " ++ s
+
 {- Usage message with lists of commands by section. -}
 usage :: String -> [Command] -> String
-usage header cmds = unlines $ header : concatMap go [minBound..]
+usage header cmds = unlines $ usageMessage header : concatMap go [minBound..]
   where
 	go section
 		| null cs = []
@@ -37,6 +42,20 @@ usage header cmds = unlines $ header : concatMap go [minBound..]
 	longest f = foldl max 0 $ map (length . f) cmds
 	scmds = sort cmds
 
+{- Usage message for a single command. -}
+commandUsage :: Command -> String
+commandUsage cmd = unlines
+	[ usageInfo header (cmdoptions cmd)
+	, "To see additional options common to all commands, run: git annex help options"
+	]
+  where
+	header = usageMessage $ unwords
+		[ "git-annex"
+		, cmdname cmd
+		, cmdparamdesc cmd
+		, "[option ...]"
+		]
+
 {- Descriptions of params used in usage messages. -}
 paramPaths :: String
 paramPaths = paramOptional $ paramRepeating paramPath -- most often used