% Copyright (C) 2007 Eric Kow
%
% This program is free software; you can redistribute it and/or modify
% it under the terms of the GNU General Public License as published by
% the Free Software Foundation; either version 2, or (at your option)
% any later version.
%
% This program is distributed in the hope that it will be useful,
% but WITHOUT ANY WARRANTY; without even the implied warranty of
% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
% GNU General Public License for more details.
%
% You should have received a copy of the GNU General Public License
% along with this program; see the file COPYING. If not, write to
% the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
% Boston, MA 02110-1301, USA.
\darcsCommand{show contents}
\begin{code}
module Darcs.Commands.ShowContents ( showContents ) where
import Control.Monad ( filterM, forM_, unless )
import Control.Monad.Trans( liftIO )
import System.IO ( stdout )
import Data.Maybe( fromJust )
import qualified Data.ByteString as B
import Darcs.Commands ( DarcsCommand(..), nodefaults )
import Darcs.Arguments ( DarcsFlag, matchOne,
workingRepoDir, fixSubPaths )
import Darcs.RepoPath ( sp2fn )
import Darcs.IO ( mReadFilePS, mDoesFileExist )
import Darcs.Patch.Match( Matcher )
import Darcs.Match ( haveNonrangeMatch, applyInvToMatcher, nonrangeMatcher
, InclusiveOrExclusive(..), matchExists )
import Darcs.Repository ( withRepository, ($-), findRepository, readRepo, readRecorded )
import Darcs.Patch( RepoPatch )
import Storage.Hashed.Monad( virtualTreeIO )
showContentsDescription :: String
showContentsDescription = "Outputs a specific version of a file."
showContentsHelp :: String
showContentsHelp =
"Show contents can be used to display an earlier version of some file(s).\n"++
"If you give show contents no version arguments, it displays the recorded\n"++
"version of the file(s).\n"
showContents :: DarcsCommand
showContents = DarcsCommand {commandName = "contents",
commandHelp = showContentsHelp,
commandDescription = showContentsDescription,
commandExtraArgs = 1,
commandExtraArgHelp
= ["[FILE]..."],
commandCommand = showContentsCmd,
commandPrereq = findRepository,
commandGetArgPossibilities = return [],
commandArgdefaults = nodefaults,
commandAdvancedOptions = [],
commandBasicOptions = [matchOne, workingRepoDir]}
getMatcher :: (RepoPatch p) => [DarcsFlag] -> Matcher p
getMatcher = fromJust . nonrangeMatcher
showContentsCmd :: [DarcsFlag] -> [String] -> IO ()
showContentsCmd _ [] = fail
"show contents needs at least one argument."
showContentsCmd opts args = withRepository opts $- \repository -> do
path_list <- map sp2fn `fmap` fixSubPaths opts args
pristine <- readRecorded repository
let matcher = getMatcher opts
unapply_to_match = applyInvToMatcher Exclusive matcher
matched <- if (haveNonrangeMatch opts)
then do patchset <- readRepo repository
unless (matchExists matcher patchset) $
fail $ "Couldn't match pattern " ++ show matcher
snd `fmap` virtualTreeIO (unapply_to_match patchset) pristine
else return pristine
let dump = do okpaths <- filterM mDoesFileExist path_list
forM_ okpaths $ \f -> do content <- mReadFilePS f
liftIO (B.hPut stdout content)
virtualTreeIO dump matched
return ()
\end{code}