src/Darcs/Commands/ShowContents.lhs

   1 %  Copyright (C) 2007 Eric Kow
   2 %
   3 %  This program is free software; you can redistribute it and/or modify
   4 %  it under the terms of the GNU General Public License as published by
   5 %  the Free Software Foundation; either version 2, or (at your option)
   6 %  any later version.
   7 %
   8 %  This program is distributed in the hope that it will be useful,
   9 %  but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 %  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11 %  GNU General Public License for more details.
  12 %
  13 %  You should have received a copy of the GNU General Public License
  14 %  along with this program; see the file COPYING.  If not, write to
  15 %  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  16 %  Boston, MA 02110-1301, USA.
  17
  18 \subsubsection{darcs show contents}
  19 \begin{code}
  20 module Darcs.Commands.ShowContents ( show_contents ) where
  21
  22 import Control.Monad ( filterM )
  23 import System.IO ( stdout )
  24 import System.FilePath ( takeFileName )
  25
  26 import qualified Data.ByteString as B
  27 import Workaround ( getCurrentDirectory )
  28
  29 import Darcs.Commands ( DarcsCommand(..), nodefaults )
  30 import Darcs.Arguments ( DarcsFlag, match_one,
  31                          working_repo_dir, fixSubPaths )
  32 import Darcs.RepoPath ( toFilePath, sp2fn )
  33 import Darcs.IO ( mReadFilePS, mDoesFileExist )
  34 import Darcs.Match ( get_partial_nonrange_match, have_nonrange_match )
  35 import Darcs.Repository ( withRepository, ($-), findRepository,
  36                           createPartialsPristineDirectoryTree )
  37 import Darcs.Lock ( withTempDir )
  38 \end{code}
  39
  40 \options{show contents}
  41 \begin{code}
  42 show_contents_description :: String
  43 show_contents_description = "Outputs a specific version of a file."
  44 \end{code}
  45 \haskell{show_contents_help}
  46 \begin{code}
  47 show_contents_help :: String
  48 show_contents_help =
  49   "Show contents can be used to display an earlier version of some file(s).\n"++
  50   "If you give show contents no version arguments, it displays the recorded\n"++
  51   "version of the file(s).\n"
  52
  53 show_contents :: DarcsCommand
  54 show_contents = DarcsCommand {command_name = "contents",
  55                               command_help = show_contents_help,
  56                               command_description = show_contents_description,
  57                               command_extra_args = -1,
  58                               command_extra_arg_help
  59                                     = ["[FILE]..."],
  60                               command_command = show_contents_cmd,
  61                               command_prereq = findRepository,
  62                               command_get_arg_possibilities = return [],
  63                               command_argdefaults = nodefaults,
  64                               command_advanced_options = [],
  65                               command_basic_options = [match_one, working_repo_dir]}
  66 \end{code}
  67
  68 \begin{code}
  69 show_contents_cmd :: [DarcsFlag] -> [String] -> IO ()
  70 show_contents_cmd opts args = withRepository opts $- \repository -> do
  71   formerdir <- getCurrentDirectory
  72   path_list <- map sp2fn `fmap` fixSubPaths opts args
  73   thename <- return $ takeFileName formerdir
  74   withTempDir thename $ \dir -> do
  75      if have_nonrange_match opts
  76         then get_partial_nonrange_match repository opts path_list
  77         else createPartialsPristineDirectoryTree repository path_list (toFilePath dir)
  78      filterM mDoesFileExist path_list >>= mapM_ (\f -> mReadFilePS f >>= B.hPut stdout)
  79 \end{code}