Stable version 0.3.6

This release is dedicated to Maxis: shaping the 90s
for yours truly with SimCity, SimCopter and El-Fish.

README.md

@@ -2,7 +2,7 @@
 
 http://www.shellcheck.net
 
-Copyright 2012-2014, Vidar 'koala_man' Holen
+Copyright 2012-2015, Vidar 'koala_man' Holen
 Licensed under the GNU Affero General Public License, v3
 
 The goals of ShellCheck are:
@@ -16,7 +16,7 @@ The goals of ShellCheck are:
   - To point out subtle caveats, corner cases and pitfalls, that may cause an
     advanced user's otherwise working script to fail under future circumstances.
 
-ShellCheck is written in Haskell, and requires at least 1 GB of RAM to compile.
+ShellCheck is written in Haskell, and requires 2 GB of memory to compile.
 
 ## Installing
 
@@ -25,9 +25,9 @@ On systems with Cabal:
     cabal update
     cabal install shellcheck
 
-On Arch Linux with community packages enabled:
+On Debian based distros:
 
-    pacman -S shellcheck
+    apt-get install shellcheck
 
 On OS X with homebrew:
 

Setup.hs

@@ -1,2 +1,43 @@
-import Distribution.Simple
-main = defaultMain
+import Distribution.PackageDescription (
+  HookedBuildInfo,
+  emptyHookedBuildInfo )
+import Distribution.Simple (
+  Args,
+  UserHooks ( preSDist ),
+  defaultMainWithHooks,
+  simpleUserHooks )
+import Distribution.Simple.Setup ( SDistFlags )
+
+-- | This requires the process package from,
+--
+--   https://hackage.haskell.org/package/process
+--
+import System.Process ( callCommand )
+
+
+-- | This will use almost the default implementation, except we switch
+--   out the default pre-sdist hook with our own, 'myPreSDist'.
+--
+main = defaultMainWithHooks myHooks
+  where
+    myHooks = simpleUserHooks { preSDist = myPreSDist }
+
+
+-- | This hook will be executed before e.g. @cabal sdist@. It runs
+--   pandoc to create the man page from shellcheck.1.md. If the pandoc
+--   command is not found, this will fail with an error message:
+--
+--     /bin/sh: pandoc: command not found
+--
+--   Since the man page is listed in the Extra-Source-Files section of
+--   our cabal file, a failure here should result in a failure to
+--   create the distribution tarball (that's a good thing).
+--
+myPreSDist :: Args -> SDistFlags -> IO HookedBuildInfo
+myPreSDist _ _ = do
+  putStrLn "Building the man page..."
+  putStrLn pandoc_cmd
+  callCommand pandoc_cmd
+  return emptyHookedBuildInfo
+  where
+    pandoc_cmd = "pandoc -s -t man shellcheck.1.md -o shellcheck.1"

ShellCheck.cabal

@@ -1,7 +1,7 @@
 Name:             ShellCheck
-Version:          0.3.4
+Version:          0.3.6
 Synopsis:         Shell script analysis tool
-License:          OtherLicense
+License:          AGPL-3
 License-file:     LICENSE
 Category:         Static Analysis
 Author:           Vidar Holen
@@ -26,6 +26,8 @@ Extra-Source-Files:
     -- documentation
     README.md
     shellcheck.1.md
+    -- built with a cabal sdist hook
+    shellcheck.1
     -- tests
     test/shellcheck.hs
 
@@ -42,11 +44,12 @@ library
       mtl,
       parsec,
       regex-compat,
-      QuickCheck >= 2.2
+      QuickCheck >= 2.7.4
     exposed-modules:
       ShellCheck.Analytics
       ShellCheck.AST
       ShellCheck.Data
+      ShellCheck.Options
       ShellCheck.Parser
       ShellCheck.Simple
     other-modules:
@@ -62,7 +65,8 @@ executable shellcheck
       mtl,
       parsec,
       regex-compat,
-      QuickCheck >= 2.2
+      transformers,
+      QuickCheck >= 2.7.4
     main-is: shellcheck.hs
 
 test-suite test-shellcheck
@@ -76,6 +80,7 @@ test-suite test-shellcheck
       mtl,
       parsec,
       regex-compat,
-      QuickCheck >= 2.2
+      transformers,
+      QuickCheck >= 2.7.4
     main-is: test/shellcheck.hs
 

ShellCheck/AST.hs

@@ -28,12 +28,12 @@ data Dashed = Dashed | Undashed deriving (Show, Eq)
 data AssignmentMode = Assign | Append deriving (Show, Eq)
 data FunctionKeyword = FunctionKeyword Bool deriving (Show, Eq)
 data FunctionParentheses = FunctionParentheses Bool deriving (Show, Eq)
-data ForInType = NormalForIn | ShortForIn deriving (Show, Eq)
 data CaseType = CaseBreak | CaseFallThrough | CaseContinue deriving (Show, Eq)
 
 data Token =
     TA_Binary Id String Token Token
     | TA_Expansion Id [Token]
+    | TA_Index Id Token
     | TA_Sequence Id [Token]
     | TA_Trinary Id Token Token Token
     | TA_Unary Id String Token
@@ -48,7 +48,6 @@ data Token =
     | T_Arithmetic Id Token
     | T_Array Id [Token]
     | T_IndexedElement Id Token Token
-    | T_ Id [Token]
     | T_Assignment Id AssignmentMode String (Maybe Token) Token
     | T_Backgrounded Id Token
     | T_Backticked Id [Token]
@@ -82,7 +81,7 @@ data Token =
     | T_Fi Id
     | T_For Id
     | T_ForArithmetic Id Token Token Token [Token]
-    | T_ForIn Id ForInType [String] [Token] [Token]
+    | T_ForIn Id String [Token] [Token]
     | T_Function Id FunctionKeyword FunctionParentheses String Token
     | T_GREATAND Id
     | T_Glob Id String
@@ -122,6 +121,8 @@ data Token =
     | T_WhileExpression Id [Token] [Token]
     | T_Annotation Id [Annotation] Token
     | T_Pipe Id String
+    | T_CoProc Id (Maybe String) Token
+    | T_CoProcBody Id Token
     deriving (Show)
 
 data Annotation = DisableComment Integer deriving (Show, Eq)
@@ -204,7 +205,7 @@ analyze f g i =
     delve (T_BraceGroup id l) = dl l $ T_BraceGroup id
     delve (T_WhileExpression id c l) = dll c l $ T_WhileExpression id
     delve (T_UntilExpression id c l) = dll c l $ T_UntilExpression id
-    delve (T_ForIn id t v w l) = dll w l $ T_ForIn id t v
+    delve (T_ForIn id v w l) = dll w l $ T_ForIn id v
     delve (T_SelectIn id v w l) = dll w l $ T_SelectIn id v
     delve (T_CaseExpression id word cases) = do
         newWord <- round word
@@ -245,7 +246,10 @@ analyze f g i =
         c <- round t3
         return $ TA_Trinary id a b c
     delve (TA_Expansion id t) = dl t $ TA_Expansion id
+    delve (TA_Index id t) = d1 t $ TA_Index id
     delve (T_Annotation id anns t) = d1 t $ T_Annotation id anns
+    delve (T_CoProc id var body) = d1 body $ T_CoProc id var
+    delve (T_CoProcBody id t) = d1 t $ T_CoProcBody id
     delve t = return t
 
 getId t = case t of
@@ -310,7 +314,7 @@ getId t = case t of
         T_BraceGroup id _  -> id
         T_WhileExpression id _ _  -> id
         T_UntilExpression id _ _  -> id
-        T_ForIn id _ _ _ _  -> id
+        T_ForIn id _ _ _  -> id
         T_SelectIn id _ _ _  -> id
         T_CaseExpression id _ _ -> id
         T_Function id _ _ _ _  -> id
@@ -330,6 +334,7 @@ getId t = case t of
         TA_Sequence id _  -> id
         TA_Trinary id _ _ _  -> id
         TA_Expansion id _  -> id
+        TA_Index id _  -> id
         T_ProcSub id _ _ -> id
         T_Glob id _ -> id
         T_ForArithmetic id _ _ _ _ -> id
@@ -338,6 +343,8 @@ getId t = case t of
         T_DollarBracket id _ -> id
         T_Annotation id _ _ -> id
         T_Pipe id _ -> id
+        T_CoProc id _ _ -> id
+        T_CoProcBody id _ -> id
 
 blank :: Monad m => Token -> m ()
 blank = const $ return ()

ShellCheck/Data.hs

@@ -27,22 +27,10 @@ internalVariables = [
     "LC_MESSAGES", "LC_NUMERIC", "LINES", "MAIL", "MAILCHECK", "MAILPATH",
     "OPTERR", "PATH", "POSIXLY_CORRECT", "PROMPT_COMMAND",
     "PROMPT_DIRTRIM", "PS1", "PS2", "PS3", "PS4", "SHELL", "TIMEFORMAT",
-    "TMOUT", "TMPDIR", "auto_resume", "histchars",
+    "TMOUT", "TMPDIR", "auto_resume", "histchars", "COPROC",
 
-    -- Zsh
-    "ARGV0", "BAUD", "cdpath", "COLUMNS", "CORRECT_IGNORE",
-    "DIRSTACKSIZE", "ENV", "FCEDIT", "fignore", "fpath", "histchars",
-    "HISTCHARS", "HISTFILE", "HISTSIZE", "HOME", "IFS", "KEYBOARD_HACK",
-    "KEYTIMEOUT", "LANG", "LC_ALL", "LC_COLLATE", "LC_CTYPE",
-    "LC_MESSAGES", "LC_NUMERIC", "LC_TIME", "LINES", "LISTMAX",
-    "LOGCHECK", "MAIL", "MAILCHECK", "mailpath", "manpath", "module_path",
-    "NULLCMD", "path", "POSTEDIT", "PROMPT", "PROMPT2", "PROMPT3",
-    "PROMPT4", "prompt", "PROMPT_EOL_MARK", "PS1", "PS2", "PS3", "PS4",
-    "psvar", "READNULLCMD", "REPORTTIME", "REPLY", "reply", "RPROMPT",
-    "RPS1", "RPROMPT2", "RPS2", "SAVEHIST", "SPROMPT", "STTY", "TERM",
-    "TERMINFO", "TIMEFMT", "TMOUT", "TMPPREFIX", "watch", "WATCHFMT",
-    "WORDCHARS", "ZBEEP", "ZDOTDIR", "ZLE_LINE_ABORTED",
-    "ZLE_REMOVE_SUFFIX_CHARS", "ZLE_SPACE_SUFFIX_CHARS"
+    -- Other
+    "USER", "TZ", "TERM"
   ]
 
 variablesWithoutSpaces = [

ShellCheck/Options.hs

@@ -0,0 +1,14 @@
+module ShellCheck.Options where
+
+data Shell = Ksh | Sh | Bash
+    deriving (Show, Eq)
+
+data AnalysisOptions = AnalysisOptions {
+    optionShellType :: Maybe Shell,
+    optionExcludes :: [Integer]
+}
+
+defaultAnalysisOptions = AnalysisOptions {
+    optionShellType = Nothing,
+    optionExcludes = []
+}

ShellCheck/Parser.hs

@@ -16,10 +16,11 @@
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 -}
 {-# LANGUAGE NoMonomorphismRestriction, TemplateHaskell #-}
-module ShellCheck.Parser (Note(..), Severity(..), parseShell, ParseResult(..), ParseNote(..), sortNotes, noteToParseNote, runTests) where
+module ShellCheck.Parser (Note(..), Severity(..), parseShell, ParseResult(..), ParseNote(..), sortNotes, noteToParseNote, runTests, readScript) where
 
 import ShellCheck.AST
 import ShellCheck.Data
+import ShellCheck.Options
 import Text.Parsec
 import Debug.Trace
 import Control.Monad
@@ -61,13 +62,13 @@ unicodeDoubleQuoteChars = "\x201C\x201D\x2033\x2036"
 
 prop_spacing = isOk spacing "  \\\n # Comment"
 spacing = do
-    x <- many (many1 linewhitespace <|> try (string "\\\n"))
+    x <- many (many1 linewhitespace <|> try (string "\\\n" >> return ""))
     optional readComment
     return $ concat x
 
 spacing1 = do
     spacing <- spacing
-    when (null spacing) $ fail "no spacing"
+    when (null spacing) $ fail "Expected whitespace"
     return spacing
 
 prop_allspacing = isOk allspacing "#foo"
@@ -84,7 +85,7 @@ allspacing = do
 
 allspacingOrFail = do
     s <- allspacing
-    when (null s) $ fail "Expected spaces"
+    when (null s) $ fail "Expected whitespace"
 
 unicodeDoubleQuote = do
     pos <- getPosition
@@ -183,9 +184,9 @@ popContext = do
         then do
             let (a:r) = v
             setCurrentContexts r
-            return [a]
+            return $ Just a
         else
-            return []
+            return Nothing
 
 pushContext c = do
     v <- getCurrentContexts
@@ -233,8 +234,8 @@ reluctantlyTill1 p end = do
 attempting rest branch =
     (try branch >> rest) <|> rest
 
-orFail parser stuff =
-    try (disregard parser) <|> (disregard stuff >> fail "nope")
+orFail parser errorAction =
+    try parser <|> (errorAction >>= fail)
 
 wasIncluded p = option False (p >> return True)
 
@@ -252,7 +253,7 @@ withContext entry p = do
         popContext
         return v
      <|> do -- p failed without consuming input, abort context
-        popContext
+        v <- popContext
         fail ""
 
 called s p = do
@@ -270,12 +271,22 @@ readConditionContents single =
                                     parseProblemAt pos WarningC 1009 "Use 'if cmd; then ..' to check exit code, or 'if [[ $(cmd) == .. ]]' to check output.")
 
   where
+    spacingOrLf = condSpacing True
+    condSpacing required = do
+        pos <- getPosition
+        space <- allspacing
+        when (required && null space) $
+            parseProblemAt pos ErrorC 1035 "You are missing a required space here."
+        when (single && '\n' `elem` space) $
+            parseProblemAt pos ErrorC 1080 "When breaking lines in [ ], you need \\ before the linefeed."
+        return space
+
     typ = if single then SingleBracket else DoubleBracket
     readCondBinaryOp = try $ do
         optional guardArithmetic
         id <- getNextId
         op <- choice (map tryOp ["==", "!=", "<=", ">=", "=~", ">", "<", "=", "\\<=", "\\>=", "\\<", "\\>"]) <|> otherOp
-        hardCondSpacing
+        spacingOrLf
         return op
       where
         tryOp s = try $ do
@@ -285,7 +296,7 @@ readConditionContents single =
         otherOp = try $ do
             id <- getNextId
             s <- readOp
-            when (s == "-a" || s == "-o") $ fail "Wrong operator"
+            when (s == "-a" || s == "-o") $ fail "Unexpected operator"
             return $ TC_Binary id typ s
 
     guardArithmetic = do
@@ -298,17 +309,14 @@ readConditionContents single =
     readCondUnaryExp = do
       op <- readCondUnaryOp
       pos <- getPosition
-      (do
-          arg <- readCondWord
-          return $ op arg)
-        <|> (do
-              parseProblemAt pos ErrorC 1019 "Expected this to be an argument to the unary condition."
-              fail "oops")
+      (readCondWord >>= return . op) `orFail` do
+          parseProblemAt pos ErrorC 1019 "Expected this to be an argument to the unary condition."
+          return "Expected an argument for the unary operator"
 
     readCondUnaryOp = try $ do
         id <- getNextId
         s <- readOp
-        hardCondSpacing
+        spacingOrLf
         return $ TC_Unary id typ s
 
     readOp = try $ do
@@ -337,19 +345,20 @@ readConditionContents single =
 
     readCondAndOp = do
         id <- getNextId
-        x <- try (string "&&" <|> string "-a")
-        softCondSpacing
-        skipLineFeeds
+        x <- try (readAndOrOp "&&" False <|> readAndOrOp "-a" True)
         return $ TC_And id typ x
 
     readCondOrOp = do
         optional guardArithmetic
         id <- getNextId
-        x <- try (string "||" <|> string "-o")
-        softCondSpacing
-        skipLineFeeds
+        x <- try (readAndOrOp "||" False <|> readAndOrOp "-o" True)
         return $ TC_Or id typ x
 
+    readAndOrOp op requiresSpacing = do
+        x <- string op
+        condSpacing requiresSpacing
+        return x
+
     readCondNoaryOrBinary = do
       id <- getNextId
       x <- readCondWord `attempting` (do
@@ -373,16 +382,21 @@ readConditionContents single =
           id <- getNextId
           pos <- getPosition
           lparen <- try $ string "(" <|> string "\\("
-          when (single && lparen == "(") $ parseProblemAt pos ErrorC 1028 "In [..] you have to escape (). Use [[..]] instead."
-          when (not single && lparen == "\\(") $ parseProblemAt pos ErrorC 1029 "In [[..]] you shouldn't escape ()."
-          if single then hardCondSpacing else disregard spacing
+          when (single && lparen == "(") $
+              parseProblemAt pos ErrorC 1028 "In [..] you have to escape (). Use [[..]] instead."
+          when (not single && lparen == "\\(") $
+              parseProblemAt pos ErrorC 1029 "In [[..]] you shouldn't escape ()."
+          condSpacing single
           x <- readCondContents
           cpos <- getPosition
           rparen <- string ")" <|> string "\\)"
-          if single then hardCondSpacing else disregard spacing
-          when (single && rparen == ")") $ parseProblemAt cpos ErrorC 1030 "In [..] you have to escape (). Use [[..]] instead."
-          when (not single && rparen == "\\)") $ parseProblemAt cpos ErrorC 1031 "In [[..]] you shouldn't escape ()."
-          when (isEscaped lparen `xor` isEscaped rparen) $ parseProblemAt pos ErrorC 1032 "Did you just escape one half of () but not the other?"
+          condSpacing single
+          when (single && rparen == ")") $
+              parseProblemAt cpos ErrorC 1030 "In [..] you have to escape (). Use [[..]] instead."
+          when (not single && rparen == "\\)") $
+              parseProblemAt cpos ErrorC 1031 "In [[..]] you shouldn't escape ()."
+          when (isEscaped lparen `xor` isEscaped rparen) $
+              parseProblemAt pos ErrorC 1032 "Did you just escape one half of () but not the other?"
           return $ TC_Group id typ x
       where
         isEscaped ('\\':_) = True
@@ -426,21 +440,15 @@ readConditionContents single =
             str <- string "|"
             return $ T_Literal id str
 
-    skipLineFeeds = do
-        pos <- getPosition
-        spacing <- allspacing
-        when (single  && '\n' `elem` spacing) $
-            parseProblemAt pos ErrorC 1080 "In [ ] you need \\ before line feeds."
-
     readCondTerm = do
         term <- readCondNot <|> readCondExpr
-        skipLineFeeds
+        condSpacing False
         return term
 
     readCondNot = do
         id <- getNextId
         char '!'
-        softCondSpacing
+        spacingOrLf
         expr <- readCondExpr
         return $ TC_Unary id typ "!" expr
 
@@ -452,7 +460,6 @@ readConditionContents single =
     readCondContents = readCondOr
 
 
-
 prop_a1 = isOk readArithmeticContents " n++ + ++c"
 prop_a2 = isOk readArithmeticContents "$N*4-(3,2)"
 prop_a3 = isOk readArithmeticContents "n|=2<<1"
@@ -462,14 +469,15 @@ prop_a6 = isOk readArithmeticContents " 1 | 2 ||3|4"
 prop_a7 = isOk readArithmeticContents "3*2**10"
 prop_a8 = isOk readArithmeticContents "3"
 prop_a9 = isOk readArithmeticContents "a^!-b"
-prop_aA = isOk readArithmeticContents "! $?"
-prop_aB = isOk readArithmeticContents "10#08 * 16#f"
-prop_aC = isOk readArithmeticContents "\"$((3+2))\" + '37'"
-prop_aD = isOk readArithmeticContents "foo[9*y+x]++"
-prop_aE = isOk readArithmeticContents "1+`echo 2`"
-prop_aF = isOk readArithmeticContents "foo[`echo foo | sed s/foo/4/g` * 3] + 4"
-prop_a10= isOk readArithmeticContents "$foo$bar"
-prop_a11= isOk readArithmeticContents "i<(0+(1+1))"
+prop_a10= isOk readArithmeticContents "! $?"
+prop_a11= isOk readArithmeticContents "10#08 * 16#f"
+prop_a12= isOk readArithmeticContents "\"$((3+2))\" + '37'"
+prop_a13= isOk readArithmeticContents "foo[9*y+x]++"
+prop_a14= isOk readArithmeticContents "1+`echo 2`"
+prop_a15= isOk readArithmeticContents "foo[`echo foo | sed s/foo/4/g` * 3] + 4"
+prop_a16= isOk readArithmeticContents "$foo$bar"
+prop_a17= isOk readArithmeticContents "i<(0+(1+1))"
+prop_a18= isOk readArithmeticContents "a?b:c"
 readArithmeticContents =
     readSequence
   where
@@ -489,10 +497,10 @@ readArithmeticContents =
 
     readArrayIndex = do
         id <- getNextId
-        start <- literal "["
+        char '['
         middle <- readArithmeticContents
-        end <- literal "]"
-        return $ T_NormalWord id [start, middle, end]
+        char ']'
+        return $ TA_Index id middle
 
     literal s = do
         id <- getNextId
@@ -511,7 +519,7 @@ readArithmeticContents =
             readNormalDollar,
             readBraced,
             readBackTicked,
-            readNormalLiteral "+-*/=%^,]"
+            readNormalLiteral "+-*/=%^,]?:"
             ]
         spacing
         return $ TA_Expansion id pieces
@@ -596,7 +604,7 @@ readArithmeticContents =
             id <- getNextId
             op <- try $ string "++" <|> string "--"
             spacing
-            return $ TA_Unary id ("|" ++ op) x
+            return $ TA_Unary id ('|':op) x
          <|>
             return x
 
@@ -613,8 +621,10 @@ prop_readCondition6 = isOk readCondition "[[ $c =~ ^[yY]$ ]]"
 prop_readCondition7 = isOk readCondition "[[ ${line} =~ ^[[:space:]]*# ]]"
 prop_readCondition8 = isOk readCondition "[[ $l =~ ogg|flac ]]"
 prop_readCondition9 = isOk readCondition "[ foo -a -f bar ]"
-prop_readCondition10= isOk readCondition "[[ a == b \n || c == d ]]"
-prop_readCondition11= isOk readCondition "[[ a == b || \n c == d ]]"
+prop_readCondition10= isOk readCondition "[[\na == b\n||\nc == d ]]"
+prop_readCondition10a= isOk readCondition "[[\na == b  ||\nc == d ]]"
+prop_readCondition10b= isOk readCondition "[[ a == b\n||\nc == d ]]"
+prop_readCondition11= isOk readCondition "[[ a == b ||\n c == d ]]"
 prop_readCondition12= isWarning readCondition "[ a == b \n -o c == d ]"
 prop_readCondition13= isOk readCondition "[[ foo =~ ^fo{1,3}$ ]]"
 readCondition = called "test expression" $ do
@@ -622,9 +632,17 @@ readCondition = called "test expression" $ do
     id <- getNextId
     open <- try (string "[[") <|> string "["
     let single = open == "["
-    condSpacingMsg False $ if single
-          then "You need spaces after the opening [ and before the closing ]."
-          else "You need spaces after the opening [[ and before the closing ]]."
+
+    pos <- getPosition
+    space <- allspacing
+    when (null space) $
+        parseProblemAt pos ErrorC 1035 $ "You need a space after the " ++
+            if single
+                then "[ and before the ]."
+                else "[[ and before the ]]."
+    when (single && '\n' `elem` space) $
+        parseProblemAt pos ErrorC 1080 "You need \\ before line feeds to break lines in [ ]."
+
     condition <- readConditionContents single
 
     cpos <- getPosition
@@ -635,14 +653,6 @@ readCondition = called "test expression" $ do
     many readCmdWord -- Read and throw away remainders to get then/do warnings. Fixme?
     return $ T_Condition id (if single then SingleBracket else DoubleBracket) condition
 
-
-hardCondSpacing = condSpacingMsg False "You need a space here."
-softCondSpacing = condSpacingMsg True "You need a space here."
-condSpacingMsg soft msg = do
-  pos <- getPosition
-  space <- spacing
-  when (null space) $ (if soft then parseNoteAt else parseProblemAt) pos ErrorC 1035 msg
-
 readAnnotationPrefix = do
     char '#'
     many linewhitespace
@@ -755,11 +765,10 @@ readDollarBracedLiteral = do
 
 prop_readProcSub1 = isOk readProcSub "<(echo test | wc -l)"
 prop_readProcSub2 = isOk readProcSub "<(  if true; then true; fi )"
-prop_readProcSub3 = isOk readProcSub "=(ls)"
 readProcSub = called "process substitution" $ do
     id <- getNextId
     dir <- try $ do
-                    x <- oneOf "<>="
+                    x <- oneOf "<>"
                     char '('
                     return [x]
     allspacing
@@ -811,6 +820,8 @@ prop_readBackTicked3 = isWarning readBackTicked "´grep \"\\\"\"´"
 prop_readBackTicked4 = isOk readBackTicked "`echo foo\necho bar`"
 prop_readBackTicked5 = isOk readSimpleCommand "echo `foo`bar"
 prop_readBackTicked6 = isWarning readSimpleCommand "echo `foo\necho `bar"
+prop_readBackTicked7 = isOk readSimpleCommand "`#inline comment`"
+prop_readBackTicked8 = isOk readSimpleCommand "echo `#comment` \\\nbar baz"
 readBackTicked = called "backtick expansion" $ do
     id <- getNextId
     startPos <- getPosition
@@ -826,7 +837,7 @@ readBackTicked = called "backtick expansion" $ do
             suggestForgotClosingQuote startPos endPos "backtick expansion"
 
     -- Result positions may be off due to escapes
-    result <- subParse subStart readCompoundList (unEscape subString)
+    result <- subParse subStart readTermOrNone (unEscape subString)
     return $ T_Backticked id result
   where
     unEscape [] = []
@@ -939,7 +950,7 @@ readNormalEscaped = called "escaped char" $ do
     pos <- getPosition
     backslash
     do
-        next <- quotable <|> oneOf "?*@!+[]{}.,"
+        next <- quotable <|> oneOf "?*@!+[]{}.,~#"
         return $ if next == '\n' then "" else [next]
       <|>
         do
@@ -1084,6 +1095,7 @@ readDollarBracket = called "$[..] expression" $ do
     string "]"
     return (T_DollarBracket id c)
 
+prop_readArithmeticExpression = isOk readArithmeticExpression "((a?b:c))"
 readArithmeticExpression = called "((..)) command" $ do
     id <- getNextId
     try (string "((")
@@ -1111,23 +1123,33 @@ readDollarExpansion = called "command expansion" $ do
     return $ T_DollarExpansion id cmds
 
 prop_readDollarVariable = isOk readDollarVariable "$@"
+prop_readDollarVariable2 = isOk (readDollarVariable >> anyChar) "$?!"
+prop_readDollarVariable3 = isWarning (readDollarVariable >> anyChar) "$10"
+prop_readDollarVariable4 = isWarning (readDollarVariable >> string "[@]") "$arr[@]"
+
 readDollarVariable = do
     id <- getNextId
+    pos <- getPosition
+
     let singleCharred p = do
         n <- p
         value <- wrap [n]
-        return (T_DollarBraced id value) `attempting` do
-            pos <- getPosition
-            num <- lookAhead $ many1 p
-            parseNoteAt pos ErrorC 1037 $ "$" ++ (n:num) ++ " is equivalent to ${" ++ [n] ++ "}"++ num ++"."
+        return (T_DollarBraced id value)
+
+    let positional = do
+        value <- singleCharred digit
+        return value `attempting` do
+            lookAhead digit
+            parseNoteAt pos ErrorC 1037 "Braces are required for positionals over 9, e.g. ${10}."
 
-    let positional = singleCharred digit
     let special = singleCharred specialVariable
 
     let regular = do
         name <- readVariableName
         value <- wrap name
-        return $ T_DollarBraced id value
+        return (T_DollarBraced id value) `attempting` do
+            lookAhead $ void (string "[@]") <|> void (string "[*]") <|> void readArrayIndex
+            parseNoteAt pos ErrorC 1087 "Braces are required when expanding arrays, as in ${array[idx]}."
 
     try $ char '$' >> (positional <|> special <|> regular)
 
@@ -1335,7 +1357,6 @@ prop_readSimpleCommand3 = isOk readSimpleCommand "export foo=(bar baz)"
 prop_readSimpleCommand4 = isOk readSimpleCommand "typeset -a foo=(lol)"
 prop_readSimpleCommand5 = isOk readSimpleCommand "time if true; then echo foo; fi"
 prop_readSimpleCommand6 = isOk readSimpleCommand "time -p ( ls -l; )"
-prop_readSimpleCommand7 = isOk readSimpleCommand "cat =(ls)"
 readSimpleCommand = called "simple command" $ do
     id1 <- getNextId
     id2 <- getNextId
@@ -1390,6 +1411,12 @@ readAndOr = do
                 then andOr
                 else T_Annotation aid annotations andOr
 
+readTermOrNone = do
+    allspacing
+    readTerm <|> do
+        eof
+        return []
+
 readTerm = do
     allspacing
     m <- readAndOr
@@ -1433,7 +1460,11 @@ readPipe = do
     spacing
     return $ T_Pipe id ('|':qualifier)
 
-readCommand = readCompoundCommand <|> readSimpleCommand
+readCommand = choice [
+    readCompoundCommand,
+    readCoProc,
+    readSimpleCommand
+    ]
 
 readCmdName = do
     f <- readNormalWord
@@ -1460,6 +1491,7 @@ readIfClause = called "if expression" $ do
     g_Fi `orFail` do
         parseProblemAt pos ErrorC 1046 "Couldn't find 'fi' for this 'if'."
         parseProblem ErrorC 1047 "Expected 'fi' matching previously mentioned 'if'."
+        return "Expected 'fi'."
 
     return $ T_IfExpression id ((condition, action):elifs) elses
 
@@ -1475,12 +1507,13 @@ readIfPart = do
     allspacing
     condition <- readTerm
 
-    optional (do
-        try . lookAhead $ g_Fi
-        parseProblemAt pos ErrorC 1049 "Did you forget the 'then' for this 'if'?")
+    ifNextToken (g_Fi <|> g_Elif) $
+        parseProblemAt pos ErrorC 1049 "Did you forget the 'then' for this 'if'?"
 
     called "then clause" $ do
-        g_Then `orFail` parseProblem ErrorC 1050 "Expected 'then'."
+        g_Then `orFail` do
+            parseProblem ErrorC 1050 "Expected 'then'."
+            return "Expected 'then'."
 
         acceptButWarn g_Semi ErrorC 1051 "No semicolons directly after 'then'."
         allspacing
@@ -1496,6 +1529,10 @@ readElifPart = called "elif clause" $ do
         parseProblemAt pos ErrorC 1075 "Use 'elif' instead of 'else if'."
     allspacing
     condition <- readTerm
+
+    ifNextToken (g_Fi <|> g_Elif) $
+        parseProblemAt pos ErrorC 1049 "Did you forget the 'then' for this 'elif'?"
+
     g_Then
     acceptButWarn g_Semi ErrorC 1052 "No semicolons directly after 'then'."
     allspacing
@@ -1514,6 +1551,11 @@ readElsePart = called "else clause" $ do
     verifyNotEmptyIf "else"
     readTerm
 
+ifNextToken parser action =
+    optional $ do
+        try . lookAhead $ parser
+        action
+
 prop_readSubshell = isOk readSubshell "( cd /foo; tar cf stuff.tar * )"
 readSubshell = called "explicit subshell" $ do
     id <- getNextId
@@ -1537,7 +1579,7 @@ readBraceGroup = called "brace group" $ do
     list <- readTerm
     char '}' <|> do
         parseProblem ErrorC 1056 "Expected a '}'. If you have one, try a ; or \\n in front of it."
-        fail "Unable to parse"
+        fail "Missing '}'"
     return $ T_BraceGroup id list
 
 prop_readWhileClause = isOk readWhileClause "while [[ -e foo ]]; do sleep 1; done"
@@ -1562,7 +1604,9 @@ readDoGroup loopPos = do
                 try . lookAhead $ g_Done
                 parseProblemAt loopPos ErrorC 1057 "Did you forget the 'do' for this loop?")
 
-    g_Do `orFail` parseProblem ErrorC 1058 "Expected 'do'."
+    g_Do `orFail` do
+        parseProblem ErrorC 1058 "Expected 'do'."
+        return "Expected 'do'."
 
     acceptButWarn g_Semi ErrorC 1059 "No semicolons directly after 'do'."
     allspacing
@@ -1575,6 +1619,7 @@ readDoGroup loopPos = do
     g_Done `orFail` do
             parseProblemAt pos ErrorC 1061 "Couldn't find 'done' for this 'do'."
             parseProblem ErrorC 1062 "Expected 'done' matching previously mentioned 'do'."
+            return "Expected 'done'."
     return commands
 
 
@@ -1587,12 +1632,12 @@ prop_readForClause7 = isOk readForClause "for ((;;)) do echo $i\ndone"
 prop_readForClause8 = isOk readForClause "for ((;;)) ; do echo $i\ndone"
 prop_readForClause9 = isOk readForClause "for i do true; done"
 prop_readForClause10= isOk readForClause "for ((;;)) { true; }"
-prop_readForClause11= isOk readForClause "for a b in *; do echo $a $b; done"
+prop_readForClause12= isWarning readForClause "for $a in *; do echo \"$a\"; done"
 readForClause = called "for loop" $ do
     pos <- getPosition
     (T_For id) <- g_For
     spacing
-    readRegular id pos <|> readArithmetic id pos
+    readArithmetic id pos <|> readRegular id pos
   where
     readArithmetic id pos = called "arithmetic for condition" $ do
         try $ string "(("
@@ -1613,25 +1658,12 @@ readForClause = called "for loop" $ do
         return list
 
     readRegular id pos = do
-        names <- readNames
-        readShort names <|> readLong names
-      where
-        readLong names = do
-            values <- readInClause <|> (optional readSequentialSep >> return [])
-            group <- readDoGroup pos
-            return $ T_ForIn id NormalForIn names values group
-        readShort names = do
-            char '('
-            allspacing
-            words <- many (readNormalWord `thenSkip` allspacing)
-            char ')'
-            allspacing
-            command <- readAndOr
-            return $ T_ForIn id ShortForIn names words [command]
-
-    readNames =
-        reluctantlyTill1 (readVariableName `thenSkip` spacing) $
-            disregard g_Do <|> disregard readInClause <|> disregard readSequentialSep
+        acceptButWarn (char '$') ErrorC 1086
+            "Don't use $ on the iterator name in for loops."
+        name <- readVariableName `thenSkip` spacing
+        values <- readInClause <|> (optional readSequentialSep >> return [])
+        group <- readDoGroup pos
+        return $ T_ForIn id name values group
 
 prop_readSelectClause1 = isOk readSelectClause "select foo in *; do echo $foo; done"
 prop_readSelectClause2 = isOk readSelectClause "select foo; do echo $foo; done"
@@ -1687,7 +1719,10 @@ readCaseItem = called "case item" $ do
     optional g_Lparen
     spacing
     pattern <- readPattern
-    g_Rparen
+    void g_Rparen <|> do
+        parseProblem ErrorC 1085
+            "Did you forget to move the ;; after extending this case item?"
+        fail "Expected ) to open a new case item"
     readLineBreak
     list <- (lookAhead readCaseSeparator >> return []) <|> readCompoundList
     separator <- readCaseSeparator `attempting` do
@@ -1749,7 +1784,31 @@ readFunctionDefinition = called "function" $ do
                 g_Rparen
             return ()
 
-        readFunctionName = many functionChars
+        readFunctionName = many1 functionChars
+
+prop_readCoProc1 = isOk readCoProc "coproc foo { echo bar; }"
+prop_readCoProc2 = isOk readCoProc "coproc { echo bar; }"
+prop_readCoProc3 = isOk readCoProc "coproc echo bar"
+readCoProc = called "coproc" $ do
+    id <- getNextId
+    try $ do
+        string "coproc"
+        whitespace
+    choice [ try $ readCompoundCoProc id, readSimpleCoProc id ]
+  where
+    readCompoundCoProc id = do
+        var <- optionMaybe $
+            readVariableName `thenSkip` whitespace
+        body <- readBody readCompoundCommand
+        return $ T_CoProc id var body
+    readSimpleCoProc id = do
+        body <- readBody readSimpleCommand
+        return $ T_CoProc id Nothing body
+    readBody parser = do
+        id <- getNextId
+        body <- parser
+        return $ T_CoProcBody id body
+
 
 readPattern = (readNormalWord `thenSkip` spacing) `sepBy1` (char '|' `thenSkip` spacing)
 
@@ -1793,8 +1852,7 @@ readLetSuffix = many1 (readIoRedirect <|> try readLetExpression <|> readCmdWord)
 -- Get whatever a parser would parse as a string
 readStringForParser parser = do
     pos <- lookAhead (parser >> getPosition)
-    s <- readUntil pos
-    return s
+    readUntil pos
   where
     readUntil endPos = anyChar `reluctantlyTill` (getPosition >>= guard . (== endPos))
 
@@ -1807,32 +1865,32 @@ prop_readAssignmentWord6 = isWarning readAssignmentWord "b += (1 2 3)"
 prop_readAssignmentWord7 = isOk readAssignmentWord "a[3$n'']=42"
 prop_readAssignmentWord8 = isOk readAssignmentWord "a[4''$(cat foo)]=42"
 prop_readAssignmentWord9 = isOk readAssignmentWord "IFS= "
+prop_readAssignmentWord9a= isOk readAssignmentWord "foo="
 prop_readAssignmentWord10= isWarning readAssignmentWord "foo$n=42"
 prop_readAssignmentWord11= isOk readAssignmentWord "foo=([a]=b [c] [d]= [e f )"
+prop_readAssignmentWord12= isOk readAssignmentWord "a[b <<= 3 + c]='thing'"
 readAssignmentWord = try $ do
     id <- getNextId
     pos <- getPosition
     optional (char '$' >> parseNote ErrorC 1066 "Don't use $ on the left side of assignments.")
     variable <- readVariableName
-    notFollowedBy2 $ do -- Special case for zsh =(..) syntax
-        spacing1
-        string "=("
     optional (readNormalDollar >> parseNoteAt pos ErrorC
                                 1067 "For indirection, use (associative) arrays or 'read \"var$n\" <<< \"value\"'")
     index <- optionMaybe readArrayIndex
-    space <- spacing
+    hasLeftSpace <- liftM (not . null) spacing
     pos <- getPosition
     op <- readAssignmentOp
-    space2 <- spacing
-    if space == "" && space2 /= ""
+    hasRightSpace <- liftM (not . null) spacing
+    isEndOfCommand <- liftM isJust $ optionMaybe (try . lookAhead $ (disregard (oneOf "\r\n;&|)") <|> eof))
+    if not hasLeftSpace && (hasRightSpace || isEndOfCommand)
       then do
-        when (variable /= "IFS") $
+        when (variable /= "IFS" && hasRightSpace) $
             parseNoteAt pos WarningC 1007
                 "Remove space after = if trying to assign a value (for empty string, use var='' ... )."
         value <- readEmptyLiteral
         return $ T_Assignment id op variable index value
       else do
-        when (space /= "" || space2 /= "") $
+        when (hasLeftSpace || hasRightSpace) $
             parseNoteAt pos ErrorC 1068 "Don't put spaces around the = in assignments."
         value <- readArray <|> readNormalWord
         spacing
@@ -1844,14 +1902,10 @@ readAssignmentWord = try $ do
         id <- getNextId
         return $ T_Literal id ""
 
--- This is only approximate. Fixme?
--- * Bash allows foo[' ' "" $(true) 2 ``]=var
--- * foo[bar] dereferences bar
 readArrayIndex = do
     char '['
     optional space
-    x <- readNormalishWord "]"
-    optional space
+    x <- readArithmeticContents
     char ']'
     return x
 
@@ -1903,8 +1957,8 @@ tryParseWordToken keyword t = try $ do
             "Scripts are case sensitive. Use '" ++ keyword ++ "', not '" ++ str ++ "'."
     return $ t id
 
-anycaseString =
-    mapM anycaseChar
+anycaseString str =
+    mapM anycaseChar str <?> str
   where
     anycaseChar c = char (toLower c) <|> char (toUpper c)
 
@@ -1942,10 +1996,12 @@ g_Rparen = tryToken ")" T_Rparen
 g_Bang = do
     id <- getNextId
     char '!'
-    softCondSpacing
+    void spacing1 <|> do
+        pos <- getPosition
+        parseProblemAt pos ErrorC 1035
+            "You are missing a required space after the !."
     return $ T_Bang id
 
-
 g_Semi = do
     notFollowedBy2 g_DSEMI
     tryToken ";" T_Semi
@@ -1958,12 +2014,21 @@ readKeyword = choice [ g_Then, g_Else, g_Elif, g_Fi, g_Do, g_Done, g_Esac, g_Rbr
 ifParse p t f =
     (lookAhead (try p) >> t) <|> f
 
+prop_readShebang1 = isOk readShebang "#!/bin/sh\n"
+prop_readShebang2 = isWarning readShebang "!# /bin/sh\n"
 readShebang = do
-    try $ string "#!"
+    try readCorrect <|> try readSwapped
     str <- many $ noneOf "\r\n"
     optional carriageReturn
     optional linefeed
     return str
+  where
+    readCorrect = void $ string "#!"
+    readSwapped = do
+        pos <- getPosition
+        string "!#"
+        parseProblemAt pos ErrorC 1084
+            "Use #!, not !#, for the shebang."
 
 prop_readScript1 = isOk readScript "#!/bin/bash\necho hello world\n"
 prop_readScript2 = isWarning readScript "#!/bin/bash\r\necho hello world\n"
@@ -1987,11 +2052,11 @@ readScript = do
             return $ T_Script id sb commands;
         } <|> do {
             parseProblem WarningC 1014 "Couldn't read any commands.";
-            return $ T_Script id sb [T_EOF id];
+            return $ T_Script id sb []
         }
       else do
         many anyChar
-        return $ T_Script id sb [T_EOF id];
+        return $ T_Script id sb [];
 
   where
     basename s = reverse . takeWhile (/= '/') . reverse $ s
@@ -2007,8 +2072,8 @@ readScript = do
     verifyShell pos s =
         case isValidShell s of
             Just True -> return ()
-            Just False -> parseProblemAt pos ErrorC 1071 "ShellCheck only supports Bourne based shell scripts, sorry!"
-            Nothing -> parseProblemAt pos InfoC 1008 "This shebang was unrecognized. Note that ShellCheck only handles Bourne based shells."
+            Just False -> parseProblemAt pos ErrorC 1071 "ShellCheck only supports sh/bash/ksh scripts. Sorry!"
+            Nothing -> parseProblemAt pos InfoC 1008 "This shebang was unrecognized. Note that ShellCheck only handles sh/bash/ksh."
 
     isValidShell s =
         let good = s == "" || any (`isPrefixOf` s) goodShells
@@ -2022,9 +2087,10 @@ readScript = do
 
     goodShells = [
         "sh",
+        "ash",
+        "dash",
         "bash",
-        "ksh",
-        "zsh"
+        "ksh"
         ]
     badShells = [
         "awk",
@@ -2032,7 +2098,8 @@ readScript = do
         "perl",
         "python",
         "ruby",
-        "tcsh"
+        "tcsh",
+        "zsh"
         ]
 
     readUtf8Bom = called "Byte Order Mark" $ string "\xFEFF"
@@ -2060,28 +2127,29 @@ sortNotes = sortBy compareNotes
 data ParseResult = ParseResult { parseResult :: Maybe (Token, Map.Map Id SourcePos), parseNotes :: [ParseNote] } deriving (Show)
 
 makeErrorFor parsecError =
-    ParseNote (errorPos parsecError) ErrorC 1072 $ getStringFromParsec $ errorMessages parsecError
+    ParseNote (errorPos parsecError) ErrorC 1072 $
+        getStringFromParsec $ errorMessages parsecError
 
 getStringFromParsec errors =
-        case map snd $ sortWith fst $ map f errors of
-            r -> unwords (take 1 $ nub r)  ++ " Fix any mentioned problems and try again."
-    where f err =
+        case map f errors of
+            r -> unwords (take 1 $ catMaybes $ reverse r)  ++
+                " Fix any mentioned problems and try again."
+    where
+        f err =
             case err of
-                UnExpect s    -> (1, unexpected s)
-                SysUnExpect s -> (2, unexpected s)
-                Expect s      -> (3, "Expected " ++ s ++ ".")
-                Message s     -> (4, s ++ ".")
-          wut "" = "eof"
-          wut x = x
-          unexpected s = "Unexpected " ++ wut s ++ "."
+                UnExpect s    ->  return $ unexpected s
+                SysUnExpect s ->  return $ unexpected s
+                Expect s      ->  return $ "Expected " ++ s ++ "."
+                Message s     ->  if null s then Nothing else return $ s ++ "."
+        unexpected s = "Unexpected " ++ (if null s then "eof" else s) ++ "."
 
-parseShell filename contents =
+parseShell options filename contents =
     case rp (parseWithNotes readScript) filename contents of
         (Right (script, map, notes), (parsenotes, _)) ->
-            ParseResult (Just (script, map)) (nub $ sortNotes $ notes ++ parsenotes)
+            ParseResult (Just (script, map)) (nub . sortNotes . excludeNotes $ notes ++ parsenotes)
         (Left err, (p, context)) ->
             ParseResult Nothing
-                (nub $ sortNotes $ p ++ notesForContext context ++ [makeErrorFor err])
+                (nub . sortNotes . excludeNotes $ p ++ notesForContext context ++ [makeErrorFor err])
   where
     isName (ContextName _ _) = True
     isName _ = False
@@ -2090,6 +2158,7 @@ parseShell filename contents =
         "Couldn't parse this " ++ str ++ "."
     second (ContextName pos str) = ParseNote pos InfoC 1009 $
         "The mentioned parser error was in this " ++ str ++ "."
+    excludeNotes = filter (\c -> codeForParseNote c `notElem` optionExcludes options)
 
 lt x = trace (show x) x
 ltt t = trace (show t)

ShellCheck/Simple.hs

@@ -18,16 +18,17 @@
 {-# LANGUAGE TemplateHaskell #-}
 module ShellCheck.Simple (shellCheck, ShellCheckComment, scLine, scColumn, scSeverity, scCode, scMessage, runTests) where
 
-import ShellCheck.Parser hiding (runTests)
-import ShellCheck.Analytics hiding (runTests)
-import Data.Maybe
-import Text.Parsec.Pos
 import Data.List
+import Data.Maybe
+import ShellCheck.Analytics hiding (runTests)
+import ShellCheck.Options
+import ShellCheck.Parser hiding (runTests)
 import Test.QuickCheck.All (quickCheckAll)
+import Text.Parsec.Pos
 
-shellCheck :: String -> [AnalysisOption] -> [ShellCheckComment]
-shellCheck script options =
-    let (ParseResult result notes) = parseShell "-" script in
+shellCheck :: AnalysisOptions -> String -> [ShellCheckComment]
+shellCheck options script =
+    let (ParseResult result notes) = parseShell options "-" script in
         let allNotes = notes ++ concat (maybeToList $ do
             (tree, posMap) <- result
             let list = runAnalytics options tree
@@ -51,21 +52,28 @@ severityToString s =
 formatNote (ParseNote pos severity code text) =
     ShellCheckComment (sourceLine pos) (sourceColumn pos) (severityToString severity) (fromIntegral code) text
 
+testCheck = shellCheck defaultAnalysisOptions { optionExcludes = [2148] } -- Ignore #! warnings
 prop_findsParseIssue =
-    let comments = shellCheck "echo \"$12\"" [] in
+    let comments = testCheck "echo \"$12\"" in
         length comments == 1 && scCode (head comments) == 1037
 prop_commentDisablesParseIssue1 =
-    null $ shellCheck "#shellcheck disable=SC1037\necho \"$12\"" []
+    null $ testCheck "#shellcheck disable=SC1037\necho \"$12\""
 prop_commentDisablesParseIssue2 =
-    null $ shellCheck "#shellcheck disable=SC1037\n#lol\necho \"$12\"" []
+    null $ testCheck "#shellcheck disable=SC1037\n#lol\necho \"$12\""
 
 prop_findsAnalysisIssue =
-    let comments = shellCheck "echo $1" [] in
+    let comments = testCheck "echo $1" in
         length comments == 1 && scCode (head comments) == 2086
 prop_commentDisablesAnalysisIssue1 =
-    null $ shellCheck "#shellcheck disable=SC2086\necho $1" []
+    null $ testCheck "#shellcheck disable=SC2086\necho $1"
 prop_commentDisablesAnalysisIssue2 =
-    null $ shellCheck "#shellcheck disable=SC2086\n#lol\necho $1" []
+    null $ testCheck "#shellcheck disable=SC2086\n#lol\necho $1"
+
+prop_optionDisablesIssue1 =
+    null $ shellCheck (defaultAnalysisOptions { optionExcludes = [2086, 2148] }) "echo $1"
+
+prop_optionDisablesIssue2 =
+    null $ shellCheck (defaultAnalysisOptions { optionExcludes = [2148, 1037] }) "echo \"$10\""
 
 return []
 runTests = $quickCheckAll

shellcheck.1.md

@@ -16,25 +16,43 @@ errors and pitfalls where the shell just gives a cryptic error message or
 strange behavior, but it also reports on a few more advanced issues where
 corner cases can cause delayed failures.
 
+ShellCheck gives shell specific advice. Consider the line:
+
+    (( area = 3.14*r*r ))
+
++ For scripts starting with `#!/bin/sh` (or when using `-s sh`), ShellCheck
+will warn that `(( .. ))` is not POSIX compliant (similar to checkbashisms).
+
++ For scripts starting with `#!/bin/bash` (or using `-s bash`), ShellCheck
+will warn that decimals are not supported.
+
++ For scripts starting with `#!/bin/ksh` (or using `-s ksh`), ShellCheck will
+not warn at all, as `ksh` supports decimals in arithmetic contexts.
+
+
 # OPTIONS
 
-**-f** *FORMAT*, **--format=***FORMAT*
-
-:   Specify the output format of shellcheck, which prints its results in the
-    standard output. Subsequent **-f** options are ignored, see **FORMATS**
-    below for more information.
-
 **-e**\ *CODE1*[,*CODE2*...],\ **--exclude=***CODE1*[,*CODE2*...]
 
 :   Explicitly exclude the specified codes from the report. Subsequent **-e**
     options are cumulative, but all the codes can be specified at once,
     comma-separated as a single argument.
 
+**-f** *FORMAT*, **--format=***FORMAT*
+
+:   Specify the output format of shellcheck, which prints its results in the
+    standard output. Subsequent **-f** options are ignored, see **FORMATS**
+    below for more information.
+
 **-s**\ *shell*,\ **--shell=***shell*
 
-:   Specify Bourne shell dialect. Valid values are *sh*, *bash*, *ksh* and
-    *zsh*. The default is to use the file's shebang, or *bash* if the target
-    shell can't be determined.
+:   Specify Bourne shell dialect. Valid values are *sh*, *bash* and *ksh*.
+    The default is to use the file's shebang, or *bash* if the target shell
+    can't be determined.
+
+**-V**\ *version*,\ **--version**
+
+:   Print version and exit.
 
 # FORMATS
 
@@ -79,11 +97,12 @@ corner cases can cause delayed failures.
 
         [
           {
-            "line": line,
-            "column": column,
-            "level": level,
-            "code": ####,
-            "message": message
+            "file": "filename",
+            "line": lineNumber,
+            "column": columnNumber,
+            "level": "severitylevel",
+            "code": errorCode,
+            "message": "warning message"
           },
           ...
         ]
@@ -100,6 +119,14 @@ For example, to suppress SC2035 about using `./*.jpg`:
     # shellcheck disable=SC2035
     echo "Files: " *.jpg
 
+Here a shell brace group is used to suppress on multiple lines:
+
+    # shellcheck disable=SC2016
+    {
+      echo 'Modifying $PATH'
+      echo 'PATH=foo:$PATH' >> ~/.bashrc
+    }
+
 Valid keys are:
 
 **disable**

shellcheck.hs

@@ -17,12 +17,17 @@
 -}
 import Control.Exception
 import Control.Monad
+import Control.Monad.Trans
+import Control.Monad.Trans.Error
+import Control.Monad.Trans.List
 import Data.Char
 import Data.Maybe
+import Data.Monoid
 import GHC.Exts
 import GHC.IO.Device
 import Prelude hiding (catch)
 import ShellCheck.Data
+import ShellCheck.Options
 import ShellCheck.Simple
 import ShellCheck.Analytics
 import System.Console.GetOpt
@@ -34,26 +39,35 @@ import Text.JSON
 import qualified Data.Map as Map
 
 data Flag = Flag String String
+data Status = NoProblems | SomeProblems | BadInput | SupportFailure | SyntaxFailure | RuntimeException deriving (Ord, Eq)
+
+data JsonComment = JsonComment FilePath ShellCheckComment
+
+instance Error Status where
+    noMsg = RuntimeException
+
+instance Monoid Status where
+    mempty = NoProblems
+    mappend = max
 
 header = "Usage: shellcheck [OPTIONS...] FILES..."
 options = [
-    Option ['f'] ["format"]
-        (ReqArg (Flag "format") "FORMAT") "output format",
-    Option ['e'] ["exclude"]
+    Option "e" ["exclude"]
         (ReqArg (Flag "exclude") "CODE1,CODE2..") "exclude types of warnings",
-    Option ['s'] ["shell"]
-        (ReqArg (Flag "shell") "SHELLNAME") "Specify dialect (bash,sh,ksh,zsh)",
-    Option ['V'] ["version"]
+    Option "f" ["format"]
+        (ReqArg (Flag "format") "FORMAT") "output format",
+    Option "s" ["shell"]
+        (ReqArg (Flag "shell") "SHELLNAME") "Specify dialect (bash,sh,ksh)",
+    Option "V" ["version"]
         (NoArg $ Flag "version" "true") "Print version information"
     ]
 
 printErr = hPutStrLn stderr
 
-syntaxFailure = ExitFailure 3
-supportFailure = ExitFailure 4
 
-instance JSON ShellCheckComment where
-  showJSON c = makeObj [
+instance JSON (JsonComment) where
+  showJSON (JsonComment filename c) = makeObj [
+      ("file", showJSON $ filename),
       ("line", showJSON $ scLine c),
       ("column", showJSON $ scColumn c),
       ("level", showJSON $ scSeverity c),
@@ -62,16 +76,15 @@ instance JSON ShellCheckComment where
       ]
   readJSON = undefined
 
+parseArguments :: [String] -> ErrorT Status IO ([Flag], [FilePath])
 parseArguments argv =
     case getOpt Permute options argv of
-        (opts, files, []) -> do
-            verifyOptions opts files
-            return $ Just (opts, files)
-
+        (opts, files, []) -> return (opts, files)
         (_, _, errors) -> do
-            printErr $ concat errors ++ "\n" ++ usageInfo header options
-            exitWith syntaxFailure
+            liftIO . printErr $ concat errors ++ "\n" ++ usageInfo header options
+            throwError SyntaxFailure
 
+formats :: Map.Map String (AnalysisOptions -> [FilePath] -> IO Status)
 formats = Map.fromList [
     ("json", forJson),
     ("gcc", forGcc),
@@ -79,9 +92,21 @@ formats = Map.fromList [
     ("tty", forTty)
     ]
 
+toStatus = liftM (either id (const NoProblems)) . runErrorT
+
+catchExceptions :: IO Status -> IO Status
+catchExceptions action = action -- action `catch` handler
+  where
+    handler err = do
+        printErr $ show (err :: SomeException)
+        return RuntimeException
+
+checkComments comments = if null comments then NoProblems else SomeProblems
+
+forTty :: AnalysisOptions -> [FilePath] -> IO Status
 forTty options files = do
     output <- mapM doFile files
-    return $ and output
+    return $ mconcat output
   where
     clear = ansi 0
     ansi n = "\x1B[" ++ show n ++ "m"
@@ -97,7 +122,7 @@ forTty options files = do
     colorComment level comment =
         ansi (colorForLevel level) ++ comment ++ clear
 
-    doFile path = do
+    doFile path = catchExceptions $ do
         contents <- readContents path
         doInput path contents
 
@@ -119,34 +144,38 @@ forTty options files = do
             mapM_ (\c -> putStrLn (colorFunc (scSeverity c) $ cuteIndent c)) x
             putStrLn ""
           ) groups
-        return $ null comments
+        return . checkComments $ comments
 
     cuteIndent comment =
         replicate (scColumn comment - 1) ' ' ++
             "^-- " ++ code (scCode comment) ++ ": " ++ scMessage comment
 
-    code code = "SC" ++ (show code)
+    code code = "SC" ++ show code
 
     getColorFunc = do
         term <- hIsTerminalDevice stdout
         return $ if term then colorComment else const id
 
--- This totally ignores the filenames. Fixme?
-forJson options files = do
-    comments <- liftM concat $ mapM (commentsFor options) files
+forJson :: AnalysisOptions -> [FilePath] -> IO Status
+forJson options files = catchExceptions $ do
+    comments <- runListT $ do
+        file <- ListT $ return files
+        comment <- ListT $ commentsFor options file
+        return $ JsonComment file comment
     putStrLn $ encodeStrict comments
-    return . null $ comments
+    return $ checkComments comments
 
 -- Mimic GCC "file:line:col: (error|warning|note): message" format
+forGcc :: AnalysisOptions -> [FilePath] -> IO Status
 forGcc options files = do
     files <- mapM process files
-    return $ and files
+    return $ mconcat files
   where
-    process file = do
+    process file = catchExceptions $ do
         contents <- readContents file
         let comments = makeNonVirtual (getComments options contents) contents
         mapM_ (putStrLn . format file) comments
-        return $ null comments
+        return $ checkComments comments
 
     format filename c = concat [
             filename, ":",
@@ -162,20 +191,18 @@ forGcc options files = do
       ]
 
 -- Checkstyle compatible output. A bit of a hack to avoid XML dependencies
+forCheckstyle :: AnalysisOptions -> [FilePath] -> IO Status
 forCheckstyle options files = do
     putStrLn "<?xml version='1.0' encoding='UTF-8'?>"
     putStrLn "<checkstyle version='4.3'>"
-    statuses <- mapM (\x -> process x `catch` report) files
+    statuses <- mapM process files
     putStrLn "</checkstyle>"
-    return $ and statuses
+    return $ mconcat statuses
   where
-    process file = do
+    process file = catchExceptions $ do
         comments <- commentsFor options file
         putStrLn (formatFile file comments)
-        return $ null comments
-    report error = do
-        printErr $ show (error :: SomeException)
-        return False
+        return $ checkComments comments
 
     severity "error" = "error"
     severity "warning" = "warning"
@@ -197,31 +224,31 @@ forCheckstyle options files = do
         attr "column" $ show . scColumn $ c,
         attr "severity" $ severity . scSeverity $ c,
         attr "message" $ scMessage c,
-        attr "source" $ "ShellCheck.SC" ++ (show $ scCode c),
+        attr "source" $ "ShellCheck.SC" ++ show (scCode c),
         "/>\n"
         ]
 
-commentsFor options file =
-    liftM (getComments options) $ readContents file
+commentsFor options file = liftM (getComments options) $ readContents file
 
-getComments options contents =
-    excludeCodes (getExclusions options) $ shellCheck contents analysisOptions
-  where
-    analysisOptions = catMaybes [ shellOption ]
-    shellOption = do
-        option <- getOption options "shell"
-        sh <- shellForExecutable option
-        return $ ForceShell sh
+getComments = shellCheck
 
-
-readContents file = if file == "-" then getContents else readFile file
+readContents :: FilePath -> IO String
+readContents file =
+    if file == "-"
+    then getContents
+    else readFile file
 
 -- Realign comments from a tabstop of 8 to 1
 makeNonVirtual comments contents =
     map fix comments
   where
     ls = lines contents
-    fix c = c { scColumn = real (ls !! (scLine c - 1)) 0 0 (scColumn c) }
+    fix c = c {
+        scColumn =
+            if scLine c > 0 && scLine c <= length ls
+            then real (ls !! (scLine c - 1)) 0 0 (scColumn c)
+            else scColumn c
+    }
     real _ r v target | target <= v = r
     real [] r v _ = r -- should never happen
     real ('\t':rest) r v target =
@@ -240,7 +267,7 @@ split char str =
   where
     split' (a:rest) element =
         if a == char
-        then (reverse element) : split' rest []
+        then reverse element : split' rest []
         else split' rest (a:element)
     split' [] element = [reverse element]
 
@@ -257,45 +284,71 @@ excludeCodes codes =
 
 main = do
     args <- getArgs
-    parsedArgs <- parseArguments args
-    code <- do
-        status <- process parsedArgs
-        return $ if status then ExitSuccess else ExitFailure 1
-     `catch` return
-     `catch` \err -> do
-        printErr $ show (err :: SomeException)
-        return $ ExitFailure 2
-    exitWith code
+    status <- toStatus $ do
+        (flags, files) <- parseArguments args
+        process flags files
+    exitWith $ statusToCode status
 
-process Nothing = return False
-process (Just (options, files)) =
-  let format = fromMaybe "tty" $ getOption options "format" in
+statusToCode status =
+    case status of
+        NoProblems -> ExitSuccess
+        SomeProblems -> ExitFailure 1
+        BadInput -> ExitFailure 5
+        SyntaxFailure -> ExitFailure 3
+        SupportFailure -> ExitFailure 4
+        RuntimeException -> ExitFailure 2
+
+process :: [Flag] -> [FilePath] -> ErrorT Status IO ()
+process flags files = do
+    options <- foldM (flip parseOption) defaultAnalysisOptions flags
+    verifyFiles files
+    let format = fromMaybe "tty" $ getOption flags "format"
     case Map.lookup format formats of
         Nothing -> do
-            printErr $ "Unknown format " ++ format
-            printErr $ "Supported formats:"
-            mapM_ (printErr . write) $ Map.keys formats
-            exitWith supportFailure
+            liftIO $ do
+                printErr $ "Unknown format " ++ format
+                printErr "Supported formats:"
+                mapM_ (printErr . write) $ Map.keys formats
+            throwError SupportFailure
           where write s = "  " ++ s
-        Just f -> do
-            f options files
+        Just f -> ErrorT $ liftM Left $ f options files
 
-verifyOptions opts files = do
-    when (isJust $ getOption opts "version") printVersionAndExit
+parseOption flag options =
+    case flag of
+        Flag "shell" str ->
+                fromMaybe (die $ "Unknown shell: " ++ str) $ do
+                    shell <- shellForExecutable str
+                    return $ return options { optionShellType = Just shell }
 
-    let shell = getOption opts "shell" in
-        when (isJust shell && isNothing (shell >>= shellForExecutable)) $ do
-            printErr $ "Unknown shell: " ++ (fromJust shell)
-            exitWith supportFailure
+        Flag "exclude" str -> do
+            new <- mapM parseNum $ split ',' str
+            let old = optionExcludes options
+            return options { optionExcludes = new ++ old }
 
+        Flag "version" _ -> do
+            liftIO printVersion
+            throwError NoProblems
+
+        _ -> return options
+  where
+    die s = do
+        liftIO $ printErr s
+        throwError SupportFailure
+    parseNum ('S':'C':str) = parseNum str
+    parseNum num = do
+        unless (all isDigit num) $ do
+            liftIO . printErr $ "Bad exclusion: " ++ num
+            throwError SyntaxFailure
+        return (Prelude.read num :: Integer)
+
+verifyFiles files =
     when (null files) $ do
-        printErr "No files specified.\n"
-        printErr $ usageInfo header options
-        exitWith syntaxFailure
+        liftIO $ printErr "No files specified.\n"
+        liftIO $ printErr $ usageInfo header options
+        throwError SyntaxFailure
 
-printVersionAndExit = do
-    putStrLn $ "ShellCheck - shell script analysis tool"
+printVersion = do
+    putStrLn   "ShellCheck - shell script analysis tool"
     putStrLn $ "version: " ++ shellcheckVersion
-    putStrLn $ "license: GNU Affero General Public License, version 3"
-    putStrLn $ "website: http://www.shellcheck.net"
-    exitWith ExitSuccess
+    putStrLn   "license: GNU Affero General Public License, version 3"
+    putStrLn   "website: http://www.shellcheck.net"