summaryrefslogtreecommitdiff
path: root/src/Text/Pandoc/PDF.hs
blob: f6b3f9eedb07819396b409d6925d619cf1ca79d8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
{-# LANGUAGE OverloadedStrings #-}
{-
Copyright (C) 2012 John MacFarlane <jgm@berkeley.edu>

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 of the License, 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; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
-}

{- |
   Module      : Text.Pandoc.PDF
   Copyright   : Copyright (C) 2012 John MacFarlane
   License     : GNU GPL, version 2 or above

   Maintainer  : John MacFarlane <jgm@berkeley.edu>
   Stability   : alpha
   Portability : portable

Conversion of LaTeX documents to PDF.
-}
module Text.Pandoc.PDF ( tex2pdf ) where

import System.IO.Temp
import Data.Char (toLower)
import Data.ByteString.Lazy (ByteString)
import qualified Data.ByteString.Lazy as B
import qualified Data.ByteString.Lazy.Char8 as BC
import System.Exit (ExitCode (..))
import System.FilePath
import System.Directory
import System.Process
import Control.Exception (evaluate)
import System.IO (hClose)
import Control.Concurrent (putMVar, takeMVar, newEmptyMVar, forkIO)
import Text.Pandoc.UTF8 as UTF8

tex2pdf :: TeXProgram
        -> String                           -- ^ latex source
        -> IO (Either TeXError ByteString)
tex2pdf program source = withSystemTempDirectory "tex2pdf" $ \tmpdir ->
  tex2pdf' tmpdir program source

tex2pdf' :: FilePath                        -- ^ temp directory for output
         -> TeXProgram
         -> String                          -- ^ tex source
         -> IO (Either TeXError ByteString)
tex2pdf' tmpDir program source = do
  (exit, log', mbPdf) <- runTeXProgram program 3 tmpDir source
  case (exit, mbPdf) of
       (ExitFailure ec, _)     -> return $ Left $ extractTeXError ec log'
       (ExitSuccess, Nothing)  -> error "tex2pdf: ExitSuccess but no PDF created!"
       (ExitSuccess, Just pdf) -> return $ Right pdf

data TeXProgram = PDFLaTeX
                | XeLaTeX
                | LuaLaTeX
                | XeTeX
                | LuaTeX
                | PDFTeX
                deriving (Show, Read)

data TeXError = TeXError { exitCode   :: Int
                         , message    :: ByteString
                         , fullLog    :: ByteString
                         } deriving (Show, Read)

-- parsing output

extractTeXError :: Int -> ByteString -> TeXError
extractTeXError ec log' = TeXError { exitCode = ec
                                   , message = extractMsg log'
                                   , fullLog = log' }

extractMsg :: ByteString -> ByteString
extractMsg log' = do
  let msg'  = dropWhile (not . ("!" `BC.isPrefixOf`)) $ BC.lines log'
  let (msg'',rest) = break ("l." `BC.isPrefixOf`) msg'
  let lineno = take 1 rest
  if not (null msg')
     then BC.unlines (msg'' ++ lineno)
     else "Unknown errorR"

parseLine :: ByteString -> Bool
parseLine ln =
  if "LaTeX Warning:" `BC.isPrefixOf` ln
      then if "Rerun" `elem` ws
              then True
              else False
      else False
   where ws = BC.words ln

hasUndefinedRefs :: ByteString -> Bool
hasUndefinedRefs = or . map parseLine . BC.lines

-- running tex programs

-- Run a TeX program on an input bytestring and return (exit code,
-- contents of stdout, contents of produced PDF if any).  Rerun
-- latex as needed to resolve references, but don't run bibtex/biber.
runTeXProgram :: TeXProgram -> Int -> FilePath -> String
              -> IO (ExitCode, ByteString, Maybe ByteString)
runTeXProgram program runsLeft tmpDir source = do
  let programName = map toLower (show program)
  withTempFile tmpDir "tex2pdf" $ \file h -> do
    UTF8.hPutStr h source
    hClose h
    let programArgs = ["-halt-on-error", "-interaction", "nonstopmode",
         "-output-directory", tmpDir, file]
    (exit, out, _err) <- readCommand programName programArgs
    removeFile file
    let pdfFile = replaceDirectory (replaceExtension file ".pdf") tmpDir
    pdfExists <- doesFileExist pdfFile
    pdf <- if pdfExists
              then Just `fmap` B.readFile pdfFile
              else return Nothing
    if hasUndefinedRefs out && runsLeft > 0
       then runTeXProgram program (runsLeft - 1) tmpDir source
       else return (exit, out, pdf)

-- utility functions

-- Run a command and return exitcode, contents of stdout, and
-- contents of stderr. (Based on
-- 'readProcessWithExitCode' from 'System.Process'.)
readCommand :: FilePath                            -- ^ command to run
            -> [String]                            -- ^ any arguments
            -> IO (ExitCode,ByteString,ByteString) -- ^ exitcode, stdout, stderr

readCommand cmd args = do
    (Just inh, Just outh, Just errh, pid) <-
        createProcess (proc cmd args){ std_in  = CreatePipe,
                                       std_out = CreatePipe,
                                       std_err = CreatePipe }
    outMVar <- newEmptyMVar
    -- fork off a thread to start consuming stdout
    out  <- B.hGetContents outh
    _ <- forkIO $ evaluate (B.length out) >> putMVar outMVar ()
    -- fork off a thread to start consuming stderr
    err  <- B.hGetContents errh
    _ <- forkIO $ evaluate (B.length err) >> putMVar outMVar ()
    -- now write and flush any input
    hClose inh -- done with stdin
    -- wait on the output
    takeMVar outMVar
    takeMVar outMVar
    hClose outh
    -- wait on the process
    ex <- waitForProcess pid
    return (ex, out, err)