{- This file is part of ShellCheck. http://www.vidarholen.net/contents/shellcheck ShellCheck is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. ShellCheck 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 Affero General Public License for more details. You should have received a copy of the GNU Affero General Public License along with this program. If not, see . -} module ShellCheck.Analytics where import ShellCheck.AST import ShellCheck.Data import ShellCheck.Parser import Control.Monad import Control.Monad.State import qualified Data.Map as Map import Data.Char import Data.Functor import Data.List import Data.Maybe import Debug.Trace import Text.Regex import Data.Maybe data Shell = Ksh | Zsh | Sh | Bash deriving (Show, Eq) genericChecks = [ runBasicAnalysis (\x -> mapM_ (flip ($) x) basicChecks) ,runBasicTreeAnalysis treeChecks ,subshellAssignmentCheck ,checkSpacefulness ,checkQuotesInLiterals ,checkShebang ,checkFunctionsUsedExternally ,checkUnusedAssignments ,checkWrongArithmeticAssignment ] checksFor Sh = map runBasicAnalysis [ checkBashisms ,checkTimeParameters ,checkCdAndBack Sh ] checksFor Ksh = map runBasicAnalysis [ checkEchoSed ,checkCdAndBack Ksh ] checksFor Zsh = map runBasicAnalysis [ checkTimeParameters ,checkEchoSed ,checkCdAndBack Zsh ] checksFor Bash = map runBasicAnalysis [ checkTimeParameters ,checkBraceExpansionVars ,checkEchoSed ,checkCdAndBack Bash ] runAllAnalytics root m = addToMap notes m where shell = determineShell root notes = checkList ((checksFor shell) ++ genericChecks) root checkList l t = concatMap (\f -> f t) l addToMap list map = foldr (\(id,note) m -> Map.adjust (\(Metadata pos notes) -> Metadata pos (note:notes)) id m) map list prop_determineShell0 = determineShell (T_Script (Id 0) "#!/bin/sh" []) == Sh prop_determineShell1 = determineShell (T_Script (Id 0) "#!/usr/bin/env ksh" []) == Ksh prop_determineShell2 = determineShell (T_Script (Id 0) "" []) == Bash determineShell (T_Script _ shebang _) = normalize $ shellFor shebang where shellFor s | "/env " `isInfixOf` s = head ((drop 1 $ words s)++[""]) shellFor s = reverse . takeWhile (/= '/') . reverse $ s normalize "sh" = Sh normalize "ksh" = Ksh normalize "zsh" = Zsh normalize "bash" = Bash normalize _ = Bash runBasicAnalysis f t = snd $ runState (doAnalysis f t) [] basicChecks = [ checkUuoc ,checkPipePitfalls ,checkForInQuoted ,checkForInLs ,checkShorthandIf ,checkDollarStar ,checkUnquotedDollarAt ,checkStderrRedirect ,checkUnquotedN ,checkNumberComparisons ,checkSingleBracketOperators ,checkDoubleBracketOperators ,checkNoaryWasBinary ,checkConstantNoary ,checkForDecimals ,checkDivBeforeMult ,checkArithmeticDeref ,checkArithmeticBadOctal ,checkComparisonAgainstGlob ,checkPrintfVar ,checkCommarrays ,checkOrNeq ,checkEchoWc ,checkConstantIfs ,checkTr ,checkPipedAssignment ,checkAssignAteCommand ,checkUuoe ,checkFindNameGlob ,checkGrepRe ,checkNeedlessCommands ,checkQuotedCondRegex ,checkForInCat ,checkFindExec ,checkValidCondOps ,checkGlobbedRegex ,checkTrapQuotes ,checkTestRedirects ,checkIndirectExpansion ,checkSudoRedirect ,checkPS1Assignments ,checkBackticks ,checkInexplicablyUnquoted ,checkTildeInQuotes ,checkLonelyDotDash ,checkSpuriousExec ,checkSpuriousExpansion ,checkUnusedEchoEscapes ,checkDollarBrackets ,checkSshHereDoc ,checkSshCommandString ,checkGlobsAsOptions ,checkWhileReadPitfalls ,checkArithmeticOpCommand ,checkCharRangeGlob ] treeChecks = [ checkUnquotedExpansions ,checkSingleQuotedVariables ,checkRedirectToSame ,checkPrefixAssignmentReference ] runBasicTreeAnalysis checks token = checkList (map runTree checks) token where parentTree = getParentTree token runTree f t = runBasicAnalysis (flip f $ parentTree) t filterByAnnotation token metadataMap = Map.mapWithKey removeVals metadataMap where removeVals id (Metadata pos notes) = Metadata pos $ filter (not . shouldIgnore id . numFor) notes numFor (Note _ code _) = code shouldIgnore id num = any (shouldIgnoreFor num) $ getPath parents (T_Bang id) shouldIgnoreFor num (T_Annotation _ anns _) = any hasNum anns where hasNum (DisableComment ts) = num == ts shouldIgnoreFor _ _ = False parents = getParentTree token addNoteFor id note = modify ((id, note):) warn id code note = addNoteFor id $ Note WarningC code $ note err id code note = addNoteFor id $ Note ErrorC code $ note info id code note = addNoteFor id $ Note InfoC code $ note style id code note = addNoteFor id $ Note StyleC code $ note isVariableStartChar x = x == '_' || x >= 'a' && x <= 'z' || x >= 'A' && x <= 'Z' isVariableChar x = isVariableStartChar x || x >= '0' && x <= '9' prop_isVariableName1 = isVariableName "_fo123" prop_isVariableName2 = not $ isVariableName "4" prop_isVariableName3 = not $ isVariableName "test: " isVariableName (x:r) = isVariableStartChar x && all isVariableChar r isVariableName _ = False willSplit x = case x of T_DollarBraced _ _ -> True T_DollarExpansion _ _ -> True T_Backticked _ _ -> True T_BraceExpansion _ s -> True T_Glob _ _ -> True T_Extglob _ _ _ -> True T_NormalWord _ l -> any willSplit l _ -> False isGlob (T_Extglob _ _ _) = True isGlob (T_Glob _ _) = True isGlob (T_NormalWord _ l) = any isGlob l isGlob _ = False wouldHaveBeenGlob s = '*' `elem` s isConfusedGlobRegex ('*':_) = True isConfusedGlobRegex [x,'*'] | x /= '\\' = True isConfusedGlobRegex _ = False isPotentiallyConfusedGlobRegex = let re = mkRegex "[a-z1-9]\\*" in isJust . matchRegex re matches string regex = isJust $ matchRegex regex string headOrDefault _ (a:_) = a headOrDefault def _ = def isConstant token = case token of T_NormalWord _ l -> all isConstant l T_DoubleQuoted _ l -> all isConstant l T_SingleQuoted _ _ -> True T_Literal _ _ -> True _ -> False isEmpty token = case token of T_NormalWord _ l -> all isEmpty l T_DoubleQuoted _ l -> all isEmpty l T_SingleQuoted _ "" -> True T_Literal _ "" -> True _ -> False makeSimple (T_NormalWord _ [f]) = f makeSimple (T_Redirecting _ _ f) = f makeSimple (T_Annotation _ _ f) = f makeSimple t = t simplify = doTransform makeSimple deadSimple (T_NormalWord _ l) = [concat (concatMap (deadSimple) l)] deadSimple (T_DoubleQuoted _ l) = [(concat (concatMap (deadSimple) l))] deadSimple (T_SingleQuoted _ s) = [s] deadSimple (T_DollarBraced _ _) = ["${VAR}"] deadSimple (T_DollarArithmetic _ _) = ["${VAR}"] deadSimple (T_DollarExpansion _ _) = ["${VAR}"] deadSimple (T_Backticked _ _) = ["${VAR}"] deadSimple (T_Glob _ s) = [s] deadSimple (T_Pipeline _ [x]) = deadSimple x deadSimple (T_Literal _ x) = [x] deadSimple (T_SimpleCommand _ vars words) = concatMap (deadSimple) words deadSimple (T_Redirecting _ _ foo) = deadSimple foo deadSimple (T_DollarSingleQuoted _ s) = [s] deadSimple (T_Annotation _ _ s) = deadSimple s deadSimple _ = [] (!!!) list i = case drop i list of [] -> Nothing (r:_) -> Just r verify f s = checkBasic f s == Just True verifyNot f s = checkBasic f s == Just False verifyFull f s = checkFull f s == Just True verifyNotFull f s = checkFull f s == Just False verifyTree f s = checkTree f s == Just True verifyNotTree f s = checkTree f s == Just False checkBasic f s = checkFull (runBasicAnalysis f) s checkTree f s = checkFull (runBasicTreeAnalysis [f]) s checkFull f s = case parseShell "-" s of (ParseResult (Just (t, m)) _) -> Just . not . null $ f t _ -> Nothing prop_checkEchoWc3 = verify checkEchoWc "n=$(echo $foo | wc -c)" checkEchoWc (T_Pipeline id [a, b]) = when (acmd == ["echo", "${VAR}"]) $ case bcmd of ["wc", "-c"] -> countMsg ["wc", "-m"] -> countMsg _ -> return () where acmd = deadSimple a bcmd = deadSimple b countMsg = style id 2000 $ "See if you can use ${#variable} instead." checkEchoWc _ = return () prop_checkEchoSed1 = verify checkEchoSed "FOO=$(echo \"$cow\" | sed 's/foo/bar/g')" prop_checkEchoSed2 = verify checkEchoSed "rm $(echo $cow | sed -e 's,foo,bar,')" checkEchoSed (T_Pipeline id [a, b]) = when (acmd == ["echo", "${VAR}"]) $ case bcmd of ["sed", v] -> checkIn v ["sed", "-e", v] -> checkIn v _ -> return () where sedRe = mkRegex "^s(.)(.*)\\1(.*)\\1g?$" acmd = deadSimple a bcmd = deadSimple b checkIn s = case matchRegex sedRe s of Just _ -> style id 2001 $ "See if you can use ${variable//search/replace} instead." _ -> return () checkEchoSed _ = return () prop_checkPipedAssignment1 = verify checkPipedAssignment "A=ls | grep foo" prop_checkPipedAssignment2 = verifyNot checkPipedAssignment "A=foo cmd | grep foo" prop_checkPipedAssignment3 = verifyNot checkPipedAssignment "A=foo" checkPipedAssignment (T_Pipeline _ (T_Redirecting _ _ (T_SimpleCommand id (_:_) []):_:_)) = warn id 2036 "If you wanted to assign the output of the pipeline, use a=$(b | c) ." checkPipedAssignment _ = return () prop_checkAssignAteCommand1 = verify checkAssignAteCommand "A=ls -l" prop_checkAssignAteCommand2 = verify checkAssignAteCommand "A=ls --sort=$foo" prop_checkAssignAteCommand3 = verify checkAssignAteCommand "A=cat foo | grep bar" prop_checkAssignAteCommand4 = verifyNot checkAssignAteCommand "A=foo ls -l" prop_checkAssignAteCommand5 = verifyNot checkAssignAteCommand "PAGER=cat grep bar" checkAssignAteCommand (T_SimpleCommand id ((T_Assignment _ _ _ _ assignmentTerm):[]) (firstWord:_)) = when ("-" `isPrefixOf` (concat $ deadSimple firstWord) || (isCommonCommand (getLiteralString assignmentTerm) && not (isCommonCommand (getLiteralString firstWord)))) $ warn id 2037 "To assign the output of a command, use var=$(cmd) ." where isCommonCommand (Just s) = s `elem` commonCommands isCommonCommand _ = False checkAssignAteCommand _ = return () prop_checkArithmeticOpCommand1 = verify checkArithmeticOpCommand "i=i + 1" prop_checkArithmeticOpCommand2 = verify checkArithmeticOpCommand "foo=bar * 2" prop_checkArithmeticOpCommand3 = verifyNot checkArithmeticOpCommand "foo + opts" checkArithmeticOpCommand (T_SimpleCommand id ((T_Assignment _ _ _ _ _):[]) (firstWord:_)) = fromMaybe (return ()) $ check <$> getGlobOrLiteralString firstWord where check op = when (op `elem` ["+", "-", "*", "/"]) $ warn (getId firstWord) 2099 $ "Use $((..)) for arithmetics, e.g. i=$((i " ++ op ++ " 2))" checkArithmeticOpCommand _ = return () prop_checkWrongArit = verifyFull checkWrongArithmeticAssignment "i=i+1" prop_checkWrongArit2 = verifyFull checkWrongArithmeticAssignment "n=2; i=n*2" checkWrongArithmeticAssignment t = runBasicAnalysis f t where regex = mkRegex "^([_a-zA-Z][_a-zA-Z0-9]*)([+*-]).+$" flow = getVariableFlow t references = foldl (flip ($)) Map.empty (map insertRef flow) insertRef (Assignment (_, _, name, _)) = Map.insert name () insertRef _ = id getNormalString (T_NormalWord _ words) = do parts <- foldl (liftM2 (\x y -> x ++ [y])) (Just []) $ map getLiterals words return $ concat parts getNormalString _ = Nothing getLiterals (T_Literal _ s) = return s getLiterals (T_Glob _ s) = return s getLiterals _ = Nothing f (T_SimpleCommand id ((T_Assignment _ _ _ _ val):[]) []) = fromMaybe (return ()) $ do str <- getNormalString val match <- matchRegex regex str var <- match !!! 0 op <- match !!! 1 Map.lookup var references return $ do warn (getId val) 2100 $ "Use $((..)) for arithmetics, e.g. i=$((i " ++ op ++ " 2))" f _ = return () prop_checkUuoc1 = verify checkUuoc "cat foo | grep bar" prop_checkUuoc2 = verifyNot checkUuoc "cat * | grep bar" prop_checkUuoc3 = verify checkUuoc "cat $var | grep bar" prop_checkUuoc4 = verifyNot checkUuoc "cat $var" checkUuoc (T_Pipeline _ ((T_Redirecting _ _ cmd):_:_)) = checkCommand "cat" f cmd where f [word] = when (isSimple word) $ style (getId word) 2002 "Useless cat. Consider 'cmd < file | ..' or 'cmd file | ..' instead." f _ = return () isSimple (T_NormalWord _ parts) = all isSimple parts isSimple (T_DollarBraced _ _) = True isSimple x = not $ willSplit x checkUuoc _ = return () prop_checkNeedlessCommands = verify checkNeedlessCommands "foo=$(expr 3 + 2)" prop_checkNeedlessCommands2 = verify checkNeedlessCommands "foo=`echo \\`expr 3 + 2\\``" prop_checkNeedlessCommands3 = verifyNot checkNeedlessCommands "foo=$(expr foo : regex)" checkNeedlessCommands cmd@(T_SimpleCommand id _ _) | cmd `isCommand` "expr" && (not $ ":" `elem` deadSimple cmd) = style id 2003 "expr is antiquated. Consider rewriting this using $((..)), ${} or [[ ]]." checkNeedlessCommands _ = return () prop_checkPipePitfalls3 = verify checkPipePitfalls "ls | grep -v mp3" prop_checkPipePitfalls4 = verifyNot checkPipePitfalls "find . -print0 | xargs -0 foo" prop_checkPipePitfalls5 = verifyNot checkPipePitfalls "ls -N | foo" prop_checkPipePitfalls6 = verify checkPipePitfalls "find . | xargs foo" checkPipePitfalls (T_Pipeline id commands) = do for ["find", "xargs"] $ \(find:xargs:_) -> let args = deadSimple xargs in when (not $ hasShortParameter args '0') $ warn (getId find) 2038 "Use either 'find .. -print0 | xargs -0 ..' or 'find .. -exec .. +' to allow for non-alphanumeric filenames." for ["?", "echo"] $ \(_:echo:_) -> info (getId echo) 2008 "echo doesn't read from stdin, are you sure you should be piping to it?" for' ["ps", "grep"] $ \x -> info x 2009 "Consider using pgrep instead of grepping ps output." didLs <- liftM or . sequence $ [ for' ["ls", "grep"] $ \x -> warn x 2010 "Don't use ls | grep. Use a glob or a for loop with a condition to allow non-alphanumeric filenames.", for' ["ls", "xargs"] $ \x -> warn x 2011 "Use 'find .. -print0 | xargs -0 ..' or 'find .. -exec .. +' to allow non-alphanumeric filenames." ] when (not didLs) $ do for ["ls", "?"] $ \(ls:_) -> (when (not $ hasShortParameter (deadSimple ls) 'N') $ info (getId ls) 2012 "Use find instead of ls to better handle non-alphanumeric filenames.") return () where for l f = let indices = indexOfSublists l (map (headOrDefault "" . deadSimple) commands) in do mapM_ f (map (\n -> take (length l) $ drop n $ commands) indices) return . not . null $ indices for' l f = for l (first f) first func (x:_) = func (getId x) first _ _ = return () hasShortParameter list char = any (\x -> "-" `isPrefixOf` x && char `elem` x) list checkPipePitfalls _ = return () indexOfSublists sub all = f 0 all where f _ [] = [] f n a@(r:rest) = let others = f (n+1) rest in if match sub a then n:others else others match ("?":r1) (_:r2) = match r1 r2 match (x1:r1) (x2:r2) | x1 == x2 = match r1 r2 match [] _ = True match _ _ = False bracedString l = concat $ deadSimple l isMagicInQuotes (T_DollarBraced _ l) | '@' `elem` (bracedString l) = True isMagicInQuotes _ = False prop_checkShebang1 = verifyFull checkShebang "#!/usr/bin/env bash -x\necho cow" prop_checkShebang2 = verifyNotFull checkShebang "#! /bin/sh -l " checkShebang (T_Script id sb _) = if (length $ words sb) > 2 then let note = Note ErrorC 2096 $ "On most OS, shebangs can only specify a single parameter." in [(id, note)] else [] prop_checkBashisms = verify checkBashisms "while read a; do :; done < <(a)" prop_checkBashisms2 = verify checkBashisms "[ foo -nt bar ]" prop_checkBashisms3 = verify checkBashisms "echo $((i++))" prop_checkBashisms4 = verify checkBashisms "rm !(*.hs)" prop_checkBashisms5 = verify checkBashisms "source file" prop_checkBashisms6 = verify checkBashisms "[ \"$a\" == 42 ]" prop_checkBashisms7 = verify checkBashisms "echo ${var[1]}" prop_checkBashisms8 = verify checkBashisms "echo ${!var[@]}" prop_checkBashisms9 = verify checkBashisms "echo ${!var*}" prop_checkBashisms10= verify checkBashisms "echo ${var:4:12}" prop_checkBashisms11= verifyNot checkBashisms "echo ${var:-4}" prop_checkBashisms12= verify checkBashisms "echo ${var//foo/bar}" prop_checkBashisms13= verify checkBashisms "exec -c env" prop_checkBashisms14= verify checkBashisms "echo -n \"Foo: \"" prop_checkBashisms15= verify checkBashisms "let n++" prop_checkBashisms16= verify checkBashisms "echo $RANDOM" prop_checkBashisms17= verify checkBashisms "echo $((RANDOM%6+1))" prop_checkBashisms18= verify checkBashisms "foo &> /dev/null" checkBashisms = bashism where errMsg id s = err id 2040 $ "#!/bin/sh was specified, so " ++ s ++ " is not supported, even when sh is actually bash." warnMsg id s = warn id 2039 $ "#!/bin/sh was specified, but " ++ s ++ " is not standard." bashism (T_ProcSub id _ _) = errMsg id "process substitution" bashism (T_Extglob id _ _) = warnMsg id "extglob" bashism (T_DollarSingleQuoted id _) = warnMsg id "$'..'" bashism (T_DollarDoubleQuoted id _) = warnMsg id "$\"..\"" bashism (T_ForArithmetic id _ _ _ _) = warnMsg id "arithmetic for loop" bashism (T_Arithmetic id _) = warnMsg id "standalone ((..))" bashism (T_DollarBracket id _) = warnMsg id "$[..] in place of $((..))" bashism (T_SelectIn id _ _ _) = warnMsg id "select loop" bashism (T_BraceExpansion id _) = warnMsg id "brace expansion" bashism (T_Condition id DoubleBracket _) = warnMsg id "[[ ]]" bashism (T_HereString id _) = warnMsg id "here-string" bashism (TC_Binary id SingleBracket op _ _) | op `elem` [ "-nt", "-ef", "\\<", "\\>", "==" ] = warnMsg id op bashism (TA_Unary id op _) | op `elem` [ "|++", "|--", "++|", "--|"] = warnMsg id (filter (/= '|') op) bashism t@(T_SimpleCommand id _ _) | t `isCommand` "source" = warnMsg id "'source' in place of '.'" bashism (T_FdRedirect id "&" (T_IoFile _ (T_Greater _) _)) = warnMsg id "&>" bashism (T_DollarBraced id token) = mapM_ check expansion where str = concat $ deadSimple token check (regex, feature) = when (isJust $ matchRegex regex str) $ warnMsg id feature bashism t@(T_SimpleCommand _ _ (cmd:arg:_)) | t `isCommand` "echo" && "-" `isPrefixOf` argString = when (not $ "--" `isPrefixOf` argString) $ -- echo "-------" warnMsg (getId arg) "echo flag" where argString = (concat $ deadSimple arg) bashism t@(T_SimpleCommand _ _ (cmd:arg:_)) | t `isCommand` "exec" && "-" `isPrefixOf` (concat $ deadSimple arg) = warnMsg (getId arg) "exec flag" bashism t@(T_SimpleCommand id _ _) | t `isCommand` "let" = warnMsg id "'let'" bashism t@(TA_Variable id "RANDOM") = warnMsg id "RANDOM" bashism _ = return() varChars="_0-9a-zA-Z" expansion = let re = mkRegex in [ (re $ "^[" ++ varChars ++ "]+\\[.*\\]$", "array references"), (re $ "^![" ++ varChars ++ "]+\\[[*@]]$", "array key expansion"), (re $ "^![" ++ varChars ++ "]+[*@]$", "name matching prefix"), (re $ "^[" ++ varChars ++ "]+:[^-=?+]", "string indexing"), (re $ "^[" ++ varChars ++ "]+(\\[.*\\])?/", "string replacement"), (re $ "^RANDOM$", "$RANDOM") ] prop_checkForInQuoted = verify checkForInQuoted "for f in \"$(ls)\"; do echo foo; done" prop_checkForInQuoted2 = verifyNot checkForInQuoted "for f in \"$@\"; do echo foo; done" prop_checkForInQuoted2a = verifyNot checkForInQuoted "for f in *.mp3; do echo foo; done" prop_checkForInQuoted2b = verify checkForInQuoted "for f in \"*.mp3\"; do echo foo; done" prop_checkForInQuoted3 = verify checkForInQuoted "for f in 'find /'; do true; done" prop_checkForInQuoted4 = verify checkForInQuoted "for f in 1,2,3; do true; done" prop_checkForInQuoted5 = verify checkForInQuoted "for f in ls; do true; done" checkForInQuoted (T_ForIn _ f [T_NormalWord _ [word@(T_DoubleQuoted id list)]] _) = when (any (\x -> willSplit x && not (isMagicInQuotes x)) list || (getLiteralString word >>= (return . wouldHaveBeenGlob)) == Just True) $ err id 2066 $ "Since you double quoted this, it will not word split, and the loop will only run once." checkForInQuoted (T_ForIn _ f [T_NormalWord _ [T_SingleQuoted id s]] _) = warn id 2041 $ "This is a literal string. To run as a command, use $(" ++ s ++ ")." checkForInQuoted (T_ForIn _ f [T_NormalWord _ [T_Literal id s]] _) = if ',' `elem` s then warn id 2042 $ "Use spaces, not commas, to separate loop elements." else warn id 2043 $ "This loop will only run once, with " ++ f ++ "='" ++ s ++ "'." checkForInQuoted _ = return () prop_checkForInCat1 = verify checkForInCat "for f in $(cat foo); do stuff; done" prop_checkForInCat1a= verify checkForInCat "for f in `cat foo`; do stuff; done" prop_checkForInCat2 = verify checkForInCat "for f in $(cat foo | grep lol); do stuff; done" prop_checkForInCat2a= verify checkForInCat "for f in `cat foo | grep lol`; do stuff; done" prop_checkForInCat3 = verifyNot checkForInCat "for f in $(cat foo | grep bar | wc -l); do stuff; done" checkForInCat (T_ForIn _ f [T_NormalWord _ w] _) = mapM_ checkF w where checkF (T_DollarExpansion id [T_Pipeline _ r]) | all isLineBased r = info id 2013 "To read lines rather than words, pipe/redirect to a 'while read' loop." checkF (T_Backticked id cmds) = checkF (T_DollarExpansion id cmds) checkF _ = return () isLineBased cmd = any (cmd `isCommand`) ["grep", "fgrep", "egrep", "sed", "cat", "awk", "cut", "sort"] checkForInCat _ = return () prop_checkForInLs = verify checkForInLs "for f in $(ls *.mp3); do mplayer \"$f\"; done" prop_checkForInLs2 = verify checkForInLs "for f in `ls *.mp3`; do mplayer \"$f\"; done" prop_checkForInLs3 = verify checkForInLs "for f in `find / -name '*.mp3'`; do mplayer \"$f\"; done" checkForInLs t = try t where try (T_ForIn _ f [T_NormalWord _ [T_DollarExpansion id [x]]] _) = check id f x try (T_ForIn _ f [T_NormalWord _ [T_Backticked id [x]]] _) = check id f x try _ = return () check id f x = case deadSimple x of ("ls":n) -> let warntype = if any ("-" `isPrefixOf`) n then warn else err in warntype id 2045 $ "Iterate over globs whenever possible (e.g. 'for f in */*.wav'), as for loops over ls will fail for filenames like 'my file*.txt'." ("find":_) -> warn id 2044 $ "Use find -exec or a while read loop instead, as for loops over find will fail for filenames like 'my file*.txt'." _ -> return () prop_checkFindExec1 = verify checkFindExec "find / -name '*.php' -exec rm {};" prop_checkFindExec2 = verify checkFindExec "find / -exec touch {} && ls {} \\;" prop_checkFindExec3 = verify checkFindExec "find / -execdir cat {} | grep lol +" prop_checkFindExec4 = verifyNot checkFindExec "find / -name '*.php' -exec foo {} +" prop_checkFindExec5 = verifyNot checkFindExec "find / -execdir bash -c 'a && b' \\;" prop_checkFindExec6 = verify checkFindExec "find / -type d -execdir rm *.jpg \\;" checkFindExec cmd@(T_SimpleCommand _ _ t@(h:r)) | cmd `isCommand` "find" = do c <- broken r False when c $ do let wordId = getId $ last t in err wordId 2067 "Missing ';' or + terminating -exec. You can't use |/||/&&, and ';' has to be a separate, quoted argument." where broken [] v = return v broken (w:r) v = do when v $ (mapM_ warnFor $ fromWord w) case getLiteralString w of Just "-exec" -> broken r True Just "-execdir" -> broken r True Just "+" -> broken r False Just ";" -> broken r False _ -> broken r v shouldWarn x = case x of T_DollarExpansion _ _ -> True T_Backticked _ _ -> True T_Glob _ _ -> True T_Extglob _ _ _ -> True _ -> False warnFor x = if shouldWarn x then info (getId x) 2014 "This will expand once before find runs, not per file found." else return () fromWord (T_NormalWord _ l) = l fromWord _ = [] checkFindExec _ = return () prop_checkUnquotedExpansions1 = verifyTree checkUnquotedExpansions "rm $(ls)" prop_checkUnquotedExpansions1a= verifyTree checkUnquotedExpansions "rm `ls`" prop_checkUnquotedExpansions2 = verifyTree checkUnquotedExpansions "rm foo$(date)" prop_checkUnquotedExpansions3 = verifyTree checkUnquotedExpansions "[ $(foo) == cow ]" prop_checkUnquotedExpansions3a= verifyTree checkUnquotedExpansions "[ ! $(foo) ]" prop_checkUnquotedExpansions4 = verifyNotTree checkUnquotedExpansions "[[ $(foo) == cow ]]" prop_checkUnquotedExpansions5 = verifyNotTree checkUnquotedExpansions "for f in $(cmd); do echo $f; done" prop_checkUnquotedExpansions6 = verifyNotTree checkUnquotedExpansions "$(cmd)" prop_checkUnquotedExpansions7 = verifyNotTree checkUnquotedExpansions "cat << foo\n$(ls)\nfoo" checkUnquotedExpansions t tree = check t where check t@(T_DollarExpansion _ _) = examine t check t@(T_Backticked _ _) = examine t check _ = return () examine t = unless (inUnquotableContext tree t || usedAsCommandName tree t) $ warn (getId t) 2046 "Quote this to prevent word splitting." prop_checkRedirectToSame = verifyTree checkRedirectToSame "cat foo > foo" prop_checkRedirectToSame2 = verifyTree checkRedirectToSame "cat lol | sed -e 's/a/b/g' > lol" prop_checkRedirectToSame3 = verifyNotTree checkRedirectToSame "cat lol | sed -e 's/a/b/g' > foo.bar && mv foo.bar lol" prop_checkRedirectToSame4 = verifyNotTree checkRedirectToSame "foo /dev/null > /dev/null" prop_checkRedirectToSame5 = verifyNotTree checkRedirectToSame "foo > bar 2> bar" checkRedirectToSame s@(T_Pipeline _ list) parents = mapM_ (\l -> (mapM_ (\x -> doAnalysis (checkOccurences x) l) (getAllRedirs list))) list where checkOccurences t@(T_NormalWord exceptId x) u@(T_NormalWord newId y) = when (exceptId /= newId && x == y && not (isOutput t && isOutput u) && not (special t)) $ do let note = Note InfoC 2094 $ "Make sure not to read and write the same file in the same pipeline." addNoteFor newId $ note addNoteFor exceptId $ note checkOccurences _ _ = return () getAllRedirs l = concatMap (\(T_Redirecting _ ls _) -> concatMap getRedirs ls) l getRedirs (T_FdRedirect _ _ (T_IoFile _ op file)) = case op of T_Greater _ -> [file] T_Less _ -> [file] T_DGREAT _ -> [file] _ -> [] getRedirs _ = [] special x = "/dev/" `isPrefixOf` (concat $ deadSimple x) isOutput t = case drop 1 $ getPath parents t of (T_IoFile _ op _):_ -> case op of T_Greater _ -> True T_DGREAT _ -> True _ -> False _ -> False checkRedirectToSame _ _ = return () prop_checkShorthandIf = verify checkShorthandIf "[[ ! -z file ]] && scp file host || rm file" prop_checkShorthandIf2 = verifyNot checkShorthandIf "[[ ! -z file ]] && { scp file host || echo 'Eek'; }" prop_checkShorthandIf3 = verifyNot checkShorthandIf "foo && bar || echo baz" prop_checkShorthandIf4 = verifyNot checkShorthandIf "foo && a=b || a=c" checkShorthandIf (T_AndIf id _ (T_OrIf _ _ (T_Pipeline _ t))) | not $ isOk t = info id 2015 "Note that A && B || C is not if-then-else. C may run when A is true." where isOk [t] = isAssignment t || (fromMaybe False $ do name <- getCommandBasename t return $ name `elem` ["echo", "exit"]) isOk _ = False checkShorthandIf _ = return () prop_checkDollarStar = verify checkDollarStar "for f in $*; do ..; done" checkDollarStar (T_NormalWord _ [(T_DollarBraced id l)]) | (bracedString l) == "*" = warn id 2048 $ "Use \"$@\" (with quotes) to prevent whitespace problems." checkDollarStar _ = return () prop_checkUnquotedDollarAt = verify checkUnquotedDollarAt "ls $@" prop_checkUnquotedDollarAt1= verifyNot checkUnquotedDollarAt "ls ${#@}" prop_checkUnquotedDollarAt2 = verify checkUnquotedDollarAt "ls ${foo[@]}" prop_checkUnquotedDollarAt3 = verifyNot checkUnquotedDollarAt "ls ${#foo[@]}" prop_checkUnquotedDollarAt4 = verifyNot checkUnquotedDollarAt "ls \"$@\"" prop_checkUnquotedDollarAt5 = verifyNot checkUnquotedDollarAt "ls ${foo/@/ at }" checkUnquotedDollarAt (T_NormalWord _ [T_DollarBraced id l]) = let string = bracedString l failing = err id 2068 $ "Add double quotes around ${" ++ string ++ "}, otherwise it's just like $* and breaks on spaces." in do when ("@" `isPrefixOf` string) failing when (not ("#" `isPrefixOf` string) && "[@]" `isInfixOf` string) failing checkUnquotedDollarAt _ = return () prop_checkStderrRedirect = verify checkStderrRedirect "test 2>&1 > cow" prop_checkStderrRedirect2 = verifyNot checkStderrRedirect "test > cow 2>&1" checkStderrRedirect (T_Redirecting _ [ T_FdRedirect id "2" (T_IoFile _ (T_GREATAND _) (T_NormalWord _ [T_Literal _ "1"])), T_FdRedirect _ _ (T_IoFile _ op _) ] _) = case op of T_Greater _ -> error T_DGREAT _ -> error _ -> return () where error = err id 2069 $ "The order of the 2>&1 and the redirect matters. The 2>&1 has to be last." checkStderrRedirect _ = return () lt x = trace ("FAILURE " ++ (show x)) x ltt t x = trace ("FAILURE " ++ (show t)) x prop_checkSingleQuotedVariables = verifyTree checkSingleQuotedVariables "echo '$foo'" prop_checkSingleQuotedVariables2 = verifyTree checkSingleQuotedVariables "echo 'lol$1.jpg'" prop_checkSingleQuotedVariables3 = verifyNotTree checkSingleQuotedVariables "sed 's/foo$/bar/'" prop_checkSingleQuotedVariables3a= verifyTree checkSingleQuotedVariables "sed 's/${foo}/bar/'" prop_checkSingleQuotedVariables3b= verifyTree checkSingleQuotedVariables "sed 's/$(echo cow)/bar/'" prop_checkSingleQuotedVariables3c= verifyTree checkSingleQuotedVariables "sed 's/$((1+foo))/bar/'" prop_checkSingleQuotedVariables4 = verifyNotTree checkSingleQuotedVariables "awk '{print $1}'" prop_checkSingleQuotedVariables5 = verifyNotTree checkSingleQuotedVariables "trap 'echo $SECONDS' EXIT" checkSingleQuotedVariables t@(T_SingleQuoted id s) parents = case matchRegex re s of Just [] -> unless (probablyOk t) $ info id 2016 $ "Expressions don't expand in single quotes, use double quotes for that." _ -> return () where probablyOk t = fromMaybe False $ do cmd <- getClosestCommand parents t name <- getCommandBasename cmd return $ name `elem` [ "trap" ,"sh" ,"bash" ,"ksh" ,"zsh" ,"ssh" ] || "awk" `isSuffixOf` name || "perl" `isPrefixOf` name re = mkRegex "\\$[{(0-9a-zA-Z_]" checkSingleQuotedVariables _ _ = return () prop_checkUnquotedN = verify checkUnquotedN "if [ -n $foo ]; then echo cow; fi" prop_checkUnquotedN2 = verify checkUnquotedN "[ -n $cow ]" prop_checkUnquotedN3 = verifyNot checkUnquotedN "[[ -n $foo ]] && echo cow" checkUnquotedN (T_Condition _ SingleBracket (TC_Unary _ SingleBracket "-n" (T_NormalWord id [t]))) | willSplit t = err id 2070 "Always true because you failed to quote. Use [[ ]] instead." checkUnquotedN _ = return () prop_checkNumberComparisons1 = verify checkNumberComparisons "[[ $foo < 3 ]]" prop_checkNumberComparisons2 = verify checkNumberComparisons "[[ 0 >= $(cmd) ]]" prop_checkNumberComparisons3 = verifyNot checkNumberComparisons "[[ $foo ]] > 3" prop_checkNumberComparisons4 = verify checkNumberComparisons "[[ $foo > 2.72 ]]" prop_checkNumberComparisons5 = verify checkNumberComparisons "[[ $foo -le 2.72 ]]" prop_checkNumberComparisons6 = verify checkNumberComparisons "[[ 3.14 = $foo ]]" checkNumberComparisons (TC_Binary id typ op lhs rhs) = do when (op `elem` ["<", ">", "<=", ">=", "\\<", "\\>", "\\<=", "\\>="]) $ do when (isNum lhs || isNum rhs) $ err id 2071 $ "\"" ++ op ++ "\" is for string comparisons. Use " ++ (eqv op) ++" ." mapM_ checkDecimals [lhs, rhs] when (op `elem` ["-lt", "-gt", "-le", "-ge", "-eq", "=", "=="]) $ do mapM_ checkDecimals [lhs, rhs] where checkDecimals hs = when (isFraction hs) $ err (getId hs) 2072 $ decimalError decimalError = "Decimals are not supported. Either use integers only, or use bc or awk to compare." isNum t = case deadSimple t of [v] -> all isDigit v _ -> False isFraction t = case deadSimple t of [v] -> isJust $ matchRegex floatRegex v _ -> False eqv ('\\':s) = eqv s eqv "<" = "-lt" eqv ">" = "-gt" eqv "<=" = "-le" eqv ">=" = "-ge" eqv _ = "the numerical equivalent" floatRegex = mkRegex "^[0-9]+\\.[0-9]+$" checkNumberComparisons _ = return () prop_checkSingleBracketOperators1 = verify checkSingleBracketOperators "[ test =~ foo ]" prop_checkSingleBracketOperators2 = verify checkSingleBracketOperators "[ $foo > $bar ]" prop_checkSingleBracketOperators3 = verifyNot checkSingleBracketOperators "[[ foo < bar ]]" prop_checkSingleBracketOperators5 = verify checkSingleBracketOperators "until [ $n <= $z ]; do echo foo; done" checkSingleBracketOperators (TC_Binary id typ op lhs rhs) | typ == SingleBracket && op `elem` ["<", ">", "<=", ">="] = err id 2073 $ "Can't use " ++ op ++" in [ ]. Escape it or use [[..]]." checkSingleBracketOperators (TC_Binary id typ op lhs rhs) | typ == SingleBracket && op == "=~" = err id 2074 $ "Can't use " ++ op ++" in [ ]. Use [[..]] instead." checkSingleBracketOperators _ = return () prop_checkDoubleBracketOperators1 = verify checkDoubleBracketOperators "[[ 3 \\< 4 ]]" prop_checkDoubleBracketOperators3 = verifyNot checkDoubleBracketOperators "[[ foo < bar ]]" checkDoubleBracketOperators x@(TC_Binary id typ op lhs rhs) | typ == DoubleBracket && op `elem` ["\\<", "\\>", "\\<=", "\\>="] = err id 2075 $ "Escaping " ++ op ++" is required in [..], but invalid in [[..]]" checkDoubleBracketOperators _ = return () prop_checkQuotedCondRegex1 = verify checkQuotedCondRegex "[[ $foo =~ \"bar\" ]]" prop_checkQuotedCondRegex2 = verify checkQuotedCondRegex "[[ $foo =~ 'cow' ]]" prop_checkQuotedCondRegex3 = verifyNot checkQuotedCondRegex "[[ $foo =~ $foo ]]" checkQuotedCondRegex (TC_Binary _ _ "=~" _ rhs) = case rhs of T_NormalWord id [T_DoubleQuoted _ _] -> error id T_NormalWord id [T_SingleQuoted _ _] -> error id _ -> return () where error id = err id 2076 $ "Don't quote rhs of =~, it'll match literally rather than as a regex." checkQuotedCondRegex _ = return () prop_checkGlobbedRegex1 = verify checkGlobbedRegex "[[ $foo =~ *foo* ]]" prop_checkGlobbedRegex2 = verify checkGlobbedRegex "[[ $foo =~ f* ]]" prop_checkGlobbedRegex2a = verify checkGlobbedRegex "[[ $foo =~ \\#* ]]" prop_checkGlobbedRegex3 = verifyNot checkGlobbedRegex "[[ $foo =~ $foo ]]" prop_checkGlobbedRegex4 = verifyNot checkGlobbedRegex "[[ $foo =~ ^c.* ]]" checkGlobbedRegex (TC_Binary _ DoubleBracket "=~" _ rhs) = let s = concat $ deadSimple rhs in if isConfusedGlobRegex s then warn (getId rhs) 2049 $ "=~ is for regex. Use == for globs." else return () checkGlobbedRegex _ = return () prop_checkConstantIfs1 = verify checkConstantIfs "[[ foo != bar ]]" prop_checkConstantIfs2 = verify checkConstantIfs "[[ n -le 4 ]]" prop_checkConstantIfs3 = verify checkConstantIfs "[[ $n -le 4 && n -ge 2 ]]" prop_checkConstantIfs4 = verifyNot checkConstantIfs "[[ $n -le 3 ]]" prop_checkConstantIfs5 = verifyNot checkConstantIfs "[[ $n -le $n ]]" checkConstantIfs (TC_Binary id typ op lhs rhs) | op `elem` [ "==", "!=", "<=", ">=", "-eq", "-ne", "-lt", "-le", "-gt", "-ge", "=~", ">", "<", "="] = do when (isJust lLit && isJust rLit) $ warn id 2050 $ "This expression is constant. Did you forget the $ on a variable?" where lLit = getLiteralString lhs rLit = getLiteralString rhs checkConstantIfs _ = return () prop_checkNoaryWasBinary = verify checkNoaryWasBinary "[[ a==$foo ]]" prop_checkNoaryWasBinary2 = verify checkNoaryWasBinary "[ $foo=3 ]" prop_checkNoaryWasBinary3 = verify checkNoaryWasBinary "[ $foo!=3 ]" checkNoaryWasBinary (TC_Noary _ _ t@(T_NormalWord id l)) | not $ isConstant t = do let str = concat $ deadSimple t when ('=' `elem` str) $ err id 2077 $ "You need spaces around the comparison operator." checkNoaryWasBinary _ = return () prop_checkConstantNoary = verify checkConstantNoary "[[ '$(foo)' ]]" prop_checkConstantNoary2 = verify checkConstantNoary "[ \"-f lol\" ]" prop_checkConstantNoary3 = verify checkConstantNoary "[[ cmd ]]" prop_checkConstantNoary4 = verify checkConstantNoary "[[ ! cmd ]]" checkConstantNoary (TC_Noary _ _ t@(T_NormalWord id _)) | isConstant t = do err id 2078 $ "This expression is constant. Did you forget a $ somewhere?" checkConstantNoary _ = return () prop_checkBraceExpansionVars = verify checkBraceExpansionVars "echo {1..$n}" checkBraceExpansionVars (T_BraceExpansion id s) | '$' `elem` s = warn id 2051 $ "Bash doesn't support variables in brace expansions." checkBraceExpansionVars _ = return () prop_checkForDecimals = verify checkForDecimals "((3.14*c))" checkForDecimals (TA_Literal id s) | any (== '.') s = do err id 2079 $ "(( )) doesn't support decimals. Use bc or awk." checkForDecimals _ = return () prop_checkDivBeforeMult = verify checkDivBeforeMult "echo $((c/n*100))" prop_checkDivBeforeMult2 = verifyNot checkDivBeforeMult "echo $((c*100/n))" checkDivBeforeMult (TA_Binary _ "*" (TA_Binary id "/" _ _) _) = do info id 2017 $ "Increase precision by replacing a/b*c with a*c/b." checkDivBeforeMult _ = return () prop_checkArithmeticDeref = verify checkArithmeticDeref "echo $((3+$foo))" prop_checkArithmeticDeref2 = verify checkArithmeticDeref "cow=14; (( s+= $cow ))" prop_checkArithmeticDeref3 = verifyNot checkArithmeticDeref "cow=1/40; (( s+= ${cow%%/*} ))" prop_checkArithmeticDeref4 = verifyNot checkArithmeticDeref "(( ! $? ))" prop_checkArithmeticDeref5 = verifyNot checkArithmeticDeref "(($1))" prop_checkArithmeticDeref6 = verifyNot checkArithmeticDeref "(( ${a[$i]} ))" checkArithmeticDeref (TA_Expansion _ (T_DollarBraced id l)) | not . excepting $ bracedString l = style id 2004 $ "Don't use $ on variables in (( ))." where excepting [] = True excepting s = (any (`elem` "/.:#%?*@[]") s) || (isDigit $ head s) checkArithmeticDeref _ = return () prop_checkArithmeticBadOctal1 = verify checkArithmeticBadOctal "(( 0192 ))" prop_checkArithmeticBadOctal2 = verifyNot checkArithmeticBadOctal "(( 0x192 ))" prop_checkArithmeticBadOctal3 = verifyNot checkArithmeticBadOctal "(( 1 ^ 0777 ))" checkArithmeticBadOctal (TA_Base id "0" (TA_Literal _ str)) | '9' `elem` str || '8' `elem` str = err id 2080 $ "Numbers with leading 0 are considered octal." checkArithmeticBadOctal _ = return () prop_checkComparisonAgainstGlob = verify checkComparisonAgainstGlob "[[ $cow == $bar ]]" prop_checkComparisonAgainstGlob2 = verifyNot checkComparisonAgainstGlob "[[ $cow == \"$bar\" ]]" prop_checkComparisonAgainstGlob3 = verify checkComparisonAgainstGlob "[ $cow = *foo* ]" prop_checkComparisonAgainstGlob4 = verifyNot checkComparisonAgainstGlob "[ $cow = foo ]" checkComparisonAgainstGlob (TC_Binary _ DoubleBracket op _ (T_NormalWord id [T_DollarBraced _ _])) | op == "=" || op == "==" = warn id 2053 $ "Quote the rhs of = in [[ ]] to prevent glob interpretation." checkComparisonAgainstGlob (TC_Binary _ SingleBracket op _ word) | (op == "=" || op == "==") && isGlob word = err (getId word) 2081 $ "[ .. ] can't match globs. Use [[ .. ]] or grep." checkComparisonAgainstGlob _ = return () prop_checkCommarrays1 = verify checkCommarrays "a=(1, 2)" prop_checkCommarrays2 = verify checkCommarrays "a+=(1,2,3)" prop_checkCommarrays3 = verifyNot checkCommarrays "cow=(1 \"foo,bar\" 3)" checkCommarrays (T_Array id l) = if any ("," `isSuffixOf`) (concatMap deadSimple l) || (length $ filter (==',') (concat $ concatMap deadSimple l)) > 1 then warn id 2054 "Use spaces, not commas, to separate array elements." else return () checkCommarrays _ = return () prop_checkOrNeq1 = verify checkOrNeq "if [[ $lol -ne cow || $lol -ne foo ]]; then echo foo; fi" prop_checkOrNeq2 = verify checkOrNeq "(( a!=lol || a!=foo ))" prop_checkOrNeq3 = verify checkOrNeq "[ \"$a\" != lol || \"$a\" != foo ]" prop_checkOrNeq4 = verifyNot checkOrNeq "[ a != $cow || b != $foo ]" -- This only catches the most idiomatic cases. Fixme? checkOrNeq (TC_Or id typ op (TC_Binary _ _ op1 word1 _) (TC_Binary _ _ op2 word2 _)) | word1 == word2 && (op1 == op2 && (op1 == "-ne" || op1 == "!=")) = warn id 2055 $ "You probably wanted " ++ (if typ == SingleBracket then "-a" else "&&") ++ " here." checkOrNeq (TA_Binary id "||" (TA_Binary _ "!=" word1 _) (TA_Binary _ "!=" word2 _)) | word1 == word2 = warn id 2056 "You probably wanted && here." checkOrNeq _ = return () allModifiedVariables t = snd $ runState (doAnalysis (\x -> modify $ (++) (getModifiedVariables x)) t) [] prop_checkValidCondOps1 = verify checkValidCondOps "[[ a -xz b ]]" prop_checkValidCondOps2 = verify checkValidCondOps "[ -M a ]" prop_checkValidCondOps2a= verifyNot checkValidCondOps "[ 3 \\> 2 ]" prop_checkValidCondOps3 = verifyNot checkValidCondOps "[ 1 = 2 -a 3 -ge 4 ]" prop_checkValidCondOps4 = verifyNot checkValidCondOps "[[ ! -v foo ]]" checkValidCondOps (TC_Binary id _ s _ _) | not (s `elem` ["-nt", "-ot", "-ef", "==", "!=", "<=", ">=", "-eq", "-ne", "-lt", "-le", "-gt", "-ge", "=~", ">", "<", "=", "\\<", "\\>", "\\<=", "\\>="]) = warn id 2057 "Unknown binary operator." checkValidCondOps (TC_Unary id _ s _) | not (s `elem` [ "!", "-a", "-b", "-c", "-d", "-e", "-f", "-g", "-h", "-L", "-k", "-p", "-r", "-s", "-S", "-t", "-u", "-w", "-x", "-O", "-G", "-N", "-z", "-n", "-o", "-v", "-R"]) = warn id 2058 "Unknown unary operator." checkValidCondOps _ = return () --- Context seeking getParentTree t = snd . snd $ runState (doStackAnalysis pre post t) ([], Map.empty) where pre t = modify (\(l, m) -> (t:l, m)) post t = do ((_:rest), map) <- get case rest of [] -> put (rest, map) (x:_) -> put (rest, Map.insert (getId t) x map) getTokenMap t = snd $ runState (doAnalysis f t) (Map.empty) where f t = modify (Map.insert (getId t) t) inUnquotableContext tree t = case t of TC_Noary _ DoubleBracket _ -> True TC_Unary _ DoubleBracket _ _ -> True TC_Binary _ DoubleBracket _ _ _ -> True TA_Unary _ _ _ -> True TA_Binary _ _ _ _ -> True TA_Trinary _ _ _ _ -> True TA_Expansion _ _ -> True T_Assignment _ _ _ _ _ -> True T_Redirecting _ _ _ -> any (isCommand t) ["local", "declare", "typeset", "export"] T_DoubleQuoted _ _ -> True T_CaseExpression _ _ _ -> True T_HereDoc _ _ _ _ _ -> True T_ForIn _ _ _ _ -> True -- Pragmatically assume it's desirable here x -> case Map.lookup (getId x) tree of Nothing -> False Just parent -> inUnquotableContext tree parent isParamTo tree cmd t = go t where go x = case Map.lookup (getId x) tree of Nothing -> False Just parent -> check parent check t = case t of T_SingleQuoted _ _ -> go t T_DoubleQuoted _ _ -> go t T_NormalWord _ _ -> go t T_SimpleCommand _ _ _ -> isCommand t cmd T_Redirecting _ _ _ -> isCommand t cmd _ -> False getClosestCommand tree t = msum . map getCommand $ getPath tree t where getCommand t@(T_Redirecting _ _ _) = return t getCommand _ = Nothing usedAsCommandName tree token = go (getId token) (tail $ getPath tree token) where go currentId ((T_NormalWord id [word]):rest) | currentId == (getId word) = go id rest go currentId ((T_DoubleQuoted id [word]):rest) | currentId == (getId word) = go id rest go currentId ((T_SimpleCommand _ _ (word:_)):_) | currentId == (getId word) = True go _ _ = False -- A list of the element and all its parents getPath tree t = t : case Map.lookup (getId t) tree of Nothing -> [] Just parent -> getPath tree parent --- Command specific checks checkCommand str f t@(T_SimpleCommand id _ (cmd:rest)) = if t `isCommand` str then f rest else return () checkCommand _ _ _ = return () checkUnqualifiedCommand str f t@(T_SimpleCommand id _ (cmd:rest)) = if t `isUnqualifiedCommand` str then f rest else return () checkUnqualifiedCommand _ _ _ = return () getLiteralString = getLiteralStringExt (const Nothing) getGlobOrLiteralString = getLiteralStringExt f where f (T_Glob _ str) = return str f _ = Nothing getLiteralStringExt more t = g t where allInList l = let foo = map g l in if all isJust foo then return $ concat (catMaybes foo) else Nothing g s@(T_DoubleQuoted _ l) = allInList l g s@(T_DollarDoubleQuoted _ l) = allInList l g s@(T_NormalWord _ l) = allInList l g (T_SingleQuoted _ s) = return s g (T_Literal _ s) = return s g x = more x isLiteral t = isJust $ getLiteralString t isCommand token str = isCommandMatch token (\cmd -> cmd == str || ("/" ++ str) `isSuffixOf` cmd) isUnqualifiedCommand token str = isCommandMatch token (\cmd -> cmd == str) isCommandMatch token matcher = fromMaybe False $ do cmd <- getCommandName token return $ matcher cmd getCommandName (T_Redirecting _ _ w) = getCommandName w getCommandName (T_SimpleCommand _ _ (w:_)) = getLiteralString w getCommandName (T_Annotation _ _ t) = getCommandName t getCommandName _ = Nothing getCommandBasename = liftM basename . getCommandName basename = reverse . (takeWhile (/= '/')) . reverse isAssignment (T_Annotation _ _ w) = isAssignment w isAssignment (T_Redirecting _ _ w) = isAssignment w isAssignment (T_SimpleCommand _ (w:_) []) = True isAssignment _ = False prop_checkPrintfVar1 = verify checkPrintfVar "printf \"Lol: $s\"" prop_checkPrintfVar2 = verifyNot checkPrintfVar "printf 'Lol: $s'" prop_checkPrintfVar3 = verify checkPrintfVar "printf -v cow $(cmd)" prop_checkPrintfVar4 = verifyNot checkPrintfVar "printf \"%${count}s\" var" checkPrintfVar = checkUnqualifiedCommand "printf" f where f (dashv:var:rest) | getLiteralString dashv == (Just "-v") = f rest f (format:params) = check format f _ = return () check format = if '%' `elem` (concat $ deadSimple format) || isLiteral format then return () else warn (getId format) 2059 $ "Don't use variables in the printf format string. Use printf \"..%s..\" \"$foo\"." prop_checkUuoe1 = verify checkUuoe "echo $(date)" prop_checkUuoe1a= verify checkUuoe "echo `date`" prop_checkUuoe2 = verify checkUuoe "echo \"$(date)\"" prop_checkUuoe2a= verify checkUuoe "echo \"`date`\"" prop_checkUuoe3 = verifyNot checkUuoe "echo \"The time is $(date)\"" checkUuoe = checkUnqualifiedCommand "echo" f where msg id = style id 2005 "Useless echo? Instead of 'echo $(cmd)', just use 'cmd'." f [T_NormalWord id [(T_DollarExpansion _ _)]] = msg id f [T_NormalWord id [T_DoubleQuoted _ [(T_DollarExpansion _ _)]]] = msg id f [T_NormalWord id [(T_Backticked _ _)]] = msg id f [T_NormalWord id [T_DoubleQuoted _ [(T_Backticked _ _)]]] = msg id f _ = return () prop_checkTr1 = verify checkTr "tr [a-f] [A-F]" prop_checkTr2 = verify checkTr "tr 'a-z' 'A-Z'" prop_checkTr2a= verify checkTr "tr '[a-z]' '[A-Z]'" prop_checkTr3 = verifyNot checkTr "tr -d '[:lower:]'" prop_checkTr3a= verifyNot checkTr "tr -d '[:upper:]'" prop_checkTr3b= verifyNot checkTr "tr -d '|/_[:upper:]'" prop_checkTr4 = verifyNot checkTr "ls [a-z]" prop_checkTr5 = verify checkTr "tr foo bar" prop_checkTr6 = verify checkTr "tr 'hello' 'world'" prop_checkTr8 = verifyNot checkTr "tr aeiou _____" prop_checkTr9 = verifyNot checkTr "a-z n-za-m" prop_checkTr10= verifyNot checkTr "tr --squeeze-repeats rl lr" prop_checkTr11= verifyNot checkTr "tr abc '[d*]'" checkTr = checkCommand "tr" (mapM_ f) where f w | isGlob w = do -- The user will go [ab] -> '[ab]' -> 'ab'. Fixme? warn (getId w) 2060 $ "Quote parameters to tr to prevent glob expansion." f word = case getLiteralString word of Just "a-z" -> info (getId word) 2018 "Use '[:lower:]' to support accents and foreign alphabets." Just "A-Z" -> info (getId word) 2019 "Use '[:upper:]' to support accents and foreign alphabets." Just s -> do -- Eliminate false positives by only looking for dupes in SET2? when ((not $ "-" `isPrefixOf` s || "[:" `isInfixOf` s) && duplicated s) $ info (getId word) 2020 "tr replaces sets of chars, not words (mentioned due to duplicates)." unless ("[:" `isPrefixOf` s) $ when ("[" `isPrefixOf` s && "]" `isSuffixOf` s && (length s > 2) && (not $ '*' `elem` s)) $ info (getId word) 2021 "Don't use [] around ranges in tr, it replaces literal square brackets." Nothing -> return () duplicated s = let relevant = filter isAlpha s in not $ relevant == nub relevant prop_checkFindNameGlob1 = verify checkFindNameGlob "find / -name *.php" prop_checkFindNameGlob2 = verify checkFindNameGlob "find / -type f -ipath *(foo)" prop_checkFindNameGlob3 = verifyNot checkFindNameGlob "find * -name '*.php'" checkFindNameGlob = checkCommand "find" f where acceptsGlob (Just s) = s `elem` [ "-ilname", "-iname", "-ipath", "-iregex", "-iwholename", "-lname", "-name", "-path", "-regex", "-wholename" ] acceptsGlob _ = False f [] = return () f [x] = return () f (a:b:r) = do when (acceptsGlob (getLiteralString a) && isGlob b) $ do let (Just s) = getLiteralString a warn (getId b) 2061 $ "Quote the parameter to " ++ s ++ " so the shell won't interpret it." f (b:r) prop_checkGrepRe1 = verify checkGrepRe "cat foo | grep *.mp3" prop_checkGrepRe2 = verify checkGrepRe "grep -Ev cow*test *.mp3" prop_checkGrepRe3 = verify checkGrepRe "grep --regex=*.mp3 file" prop_checkGrepRe4 = verifyNot checkGrepRe "grep foo *.mp3" prop_checkGrepRe5 = verifyNot checkGrepRe "grep-v --regex=moo *" prop_checkGrepRe6 = verifyNot checkGrepRe "grep foo \\*.mp3" prop_checkGrepRe7 = verify checkGrepRe "grep *foo* file" prop_checkGrepRe8 = verify checkGrepRe "ls | grep foo*.jpg" prop_checkGrepRe9 = verifyNot checkGrepRe "grep '[0-9]*' file" checkGrepRe = checkCommand "grep" f where -- --regex=*(extglob) doesn't work. Fixme? skippable (Just s) = not ("--regex=" `isPrefixOf` s) && "-" `isPrefixOf` s skippable _ = False f [] = return () f (x:r) | skippable (getLiteralString x) = f r f (re:_) = do when (isGlob re) $ do warn (getId re) 2062 $ "Quote the grep pattern so the shell won't interpret it." let string = concat $ deadSimple re if isConfusedGlobRegex string then warn (getId re) 2063 $ "Grep uses regex, but this looks like a glob." else if (isPotentiallyConfusedGlobRegex string) then info (getId re) 2022 "Note that c* does not mean \"c followed by anything\" in regex." else return () prop_checkTrapQuotes1 = verify checkTrapQuotes "trap \"echo $num\" INT" prop_checkTrapQuotes1a= verify checkTrapQuotes "trap \"echo `ls`\" INT" prop_checkTrapQuotes2 = verifyNot checkTrapQuotes "trap 'echo $num' INT" prop_checkTrapQuotes3 = verify checkTrapQuotes "trap \"echo $((1+num))\" EXIT DEBUG" checkTrapQuotes = checkCommand "trap" f where f (x:_) = checkTrap x f _ = return () checkTrap (T_NormalWord _ [T_DoubleQuoted _ rs]) = mapM_ checkExpansions rs checkTrap _ = return () warning id = warn id 2064 $ "Use single quotes, otherwise this expands now rather than when signalled." checkExpansions (T_DollarExpansion id _) = warning id checkExpansions (T_Backticked id _) = warning id checkExpansions (T_DollarBraced id _) = warning id checkExpansions (T_DollarArithmetic id _) = warning id checkExpansions _ = return () prop_checkTimeParameters1 = verify checkTimeParameters "time -f lol sleep 10" prop_checkTimeParameters2 = verifyNot checkTimeParameters "time sleep 10" prop_checkTimeParameters3 = verifyNot checkTimeParameters "time -p foo" checkTimeParameters = checkUnqualifiedCommand "time" f where f (x:_) = let s = concat $ deadSimple x in if "-" `isPrefixOf` s && s /= "-p" then info (getId x) 2023 "The shell may override 'time' as seen in man time(1). Use 'command time ..' for that one." else return () f _ = return () prop_checkTestRedirects1 = verify checkTestRedirects "test 3 > 1" prop_checkTestRedirects2 = verifyNot checkTestRedirects "test 3 \\> 1" prop_checkTestRedirects3 = verify checkTestRedirects "/usr/bin/test $var > $foo" checkTestRedirects (T_Redirecting id redirs@(redir:_) cmd) | cmd `isCommand` "test" = warn (getId redir) 2065 $ "This is interpretted as a shell file redirection, not a comparison." checkTestRedirects _ = return () prop_checkSudoRedirect1 = verify checkSudoRedirect "sudo echo 3 > /proc/file" prop_checkSudoRedirect2 = verify checkSudoRedirect "sudo cmd < input" prop_checkSudoRedirect3 = verify checkSudoRedirect "sudo cmd >> file" prop_checkSudoRedirect4 = verify checkSudoRedirect "sudo cmd &> file" prop_checkSudoRedirect5 = verifyNot checkSudoRedirect "sudo cmd 2>&1" prop_checkSudoRedirect6 = verifyNot checkSudoRedirect "sudo cmd 2> log" prop_checkSudoRedirect7 = verifyNot checkSudoRedirect "sudo cmd > /dev/null 2>&1" checkSudoRedirect (T_Redirecting _ redirs cmd) | cmd `isCommand` "sudo" = mapM_ warnAbout redirs where warnAbout (T_FdRedirect _ s (T_IoFile id op file)) | (s == "" || s == "&") && (not $ special file) = case op of T_Less _ -> info (getId op) 2024 $ "sudo doesn't affect redirects. Use sudo cat file | .." T_Greater _ -> warn (getId op) 2024 $ "sudo doesn't affect redirects. Use ..| sudo tee file" T_DGREAT _ -> warn (getId op) 2024 $ "sudo doesn't affect redirects. Use .. | sudo tee -a file" _ -> return () warnAbout _ = return () special file = (concat $ deadSimple file) == "/dev/null" checkSudoRedirect _ = return () prop_checkPS11 = verify checkPS1Assignments "PS1='\\033[1;35m\\$ '" prop_checkPS11a= verify checkPS1Assignments "export PS1='\\033[1;35m\\$ '" prop_checkPSf2 = verify checkPS1Assignments "PS1='\\h \\e[0m\\$ '" prop_checkPS13 = verify checkPS1Assignments "PS1=$'\\x1b[c '" prop_checkPS14 = verify checkPS1Assignments "PS1=$'\\e[3m; '" prop_checkPS14a= verify checkPS1Assignments "export PS1=$'\\e[3m; '" prop_checkPS15 = verifyNot checkPS1Assignments "PS1='\\[\\033[1;35m\\]\\$ '" prop_checkPS16 = verifyNot checkPS1Assignments "PS1='\\[\\e1m\\e[1m\\]\\$ '" prop_checkPS17 = verifyNot checkPS1Assignments "PS1='e033x1B'" prop_checkPS18 = verifyNot checkPS1Assignments "PS1='\\[\\e\\]'" checkPS1Assignments (T_Assignment _ _ "PS1" _ word) = warnFor word where warnFor word = let contents = concat $ deadSimple word in when (containsUnescaped contents) $ info (getId word) 2025 "Make sure all escape sequences are enclosed in \\[..\\] to prevent line wrapping issues" containsUnescaped s = let unenclosed = subRegex enclosedRegex s "" in isJust $ matchRegex escapeRegex unenclosed enclosedRegex = mkRegex "\\\\\\[.*\\\\\\]" -- FIXME: shouldn't be eager escapeRegex = mkRegex "\\\\x1[Bb]|\\\\e|\x1B|\\\\033" checkPS1Assignments _ = return () prop_checkBackticks1 = verify checkBackticks "echo `foo`" prop_checkBackticks2 = verifyNot checkBackticks "echo $(foo)" checkBackticks (T_Backticked id _) = style id 2006 "Use $(..) instead of deprecated `..`" checkBackticks _ = return () prop_checkIndirectExpansion1 = verify checkIndirectExpansion "${foo$n}" prop_checkIndirectExpansion2 = verifyNot checkIndirectExpansion "${foo//$n/lol}" prop_checkIndirectExpansion3 = verify checkIndirectExpansion "${$#}" prop_checkIndirectExpansion4 = verify checkIndirectExpansion "${var${n}_$((i%2))}" prop_checkIndirectExpansion5 = verifyNot checkIndirectExpansion "${bar}" checkIndirectExpansion (T_DollarBraced i (T_NormalWord _ contents)) = when (isIndirection contents) $ err i 2082 "To expand via indirection, use name=\"foo$n\"; echo \"${!name}\"." where isIndirection vars = let list = catMaybes (map isIndirectionPart vars) in not (null list) && all id list isIndirectionPart t = case t of T_DollarExpansion _ _ -> Just True T_Backticked _ _ -> Just True T_DollarBraced _ _ -> Just True T_DollarArithmetic _ _ -> Just True T_Literal _ s -> if all isVariableChar s then Nothing else Just False _ -> Just False checkIndirectExpansion _ = return () prop_checkInexplicablyUnquoted1 = verify checkInexplicablyUnquoted "echo 'var='value';'" prop_checkInexplicablyUnquoted2 = verifyNot checkInexplicablyUnquoted "'foo'*" prop_checkInexplicablyUnquoted3 = verifyNot checkInexplicablyUnquoted "wget --user-agent='something'" checkInexplicablyUnquoted (T_NormalWord id tokens) = mapM_ check (tails tokens) where check ((T_SingleQuoted _ _):(T_Literal id str):_) | all isAlphaNum str = info id 2026 $ "This word is outside of quotes. Did you intend to 'nest '\"'single quotes'\"' instead'? " check ((T_DoubleQuoted _ _):trapped:(T_DoubleQuoted _ _):_) = case trapped of T_DollarExpansion id _ -> warnAbout id T_DollarBraced id _ -> warnAbout id _ -> return () check _ = return () warnAbout id = info id 2027 $ "Surrounding quotes actually unquotes this (\"inside\"$outside\"inside\"). Did you forget your quote level?" checkInexplicablyUnquoted _ = return () prop_checkTildeInQuotes1 = verify checkTildeInQuotes "var=\"~/out.txt\"" prop_checkTildeInQuotes2 = verify checkTildeInQuotes "foo > '~/dir'" prop_checkTildeInQuotes4 = verifyNot checkTildeInQuotes "~/file" prop_checkTildeInQuotes5 = verifyNot checkTildeInQuotes "echo '/~foo/cow'" prop_checkTildeInQuotes6 = verifyNot checkTildeInQuotes "awk '$0 ~ /foo/'" checkTildeInQuotes = check where verify id ('~':_) = warn id 2088 "Note that ~ does not expand in quotes." verify _ _ = return () check (T_NormalWord _ ((T_SingleQuoted id str):_)) = verify id str check (T_NormalWord _ ((T_DoubleQuoted _ ((T_Literal id str):_)):_)) = verify id str check _ = return () prop_checkLonelyDotDash1 = verify checkLonelyDotDash "./ file" prop_checkLonelyDotDash2 = verifyNot checkLonelyDotDash "./file" checkLonelyDotDash t@(T_Redirecting id _ _) | isUnqualifiedCommand t "./" = err id 2083 "Don't add spaces after the slash in './file'." checkLonelyDotDash _ = return () prop_checkSpuriousExec1 = verify checkSpuriousExec "exec foo; true" prop_checkSpuriousExec2 = verify checkSpuriousExec "if a; then exec b; exec c; fi" prop_checkSpuriousExec3 = verifyNot checkSpuriousExec "echo cow; exec foo" prop_checkSpuriousExec4 = verifyNot checkSpuriousExec "if a; then exec b; fi" prop_checkSpuriousExec5 = verifyNot checkSpuriousExec "exec > file; cmd" prop_checkSpuriousExec6 = verify checkSpuriousExec "exec foo > file; cmd" prop_checkSpuriousExec7 = verifyNot checkSpuriousExec "exec file; echo failed; exit 3" checkSpuriousExec = doLists where doLists (T_Script _ _ cmds) = doList cmds doLists (T_BraceGroup _ cmds) = doList cmds doLists (T_WhileExpression _ _ cmds) = doList cmds doLists (T_UntilExpression _ _ cmds) = doList cmds doLists (T_ForIn _ _ _ cmds) = doList cmds doLists (T_IfExpression _ thens elses) = do mapM_ (\(_, l) -> doList l) thens doList elses doLists _ = return () stripCleanup = reverse . dropWhile cleanup . reverse cleanup (T_Pipeline _ [cmd]) = isCommandMatch cmd (`elem` ["echo", "exit"]) cleanup _ = False doList = doList' . stripCleanup doList' t@(current:following:_) = do commentIfExec current doList (tail t) doList' _ = return () commentIfExec (T_Pipeline id list) = mapM_ commentIfExec $ take 1 list commentIfExec (T_Redirecting _ _ f@( T_SimpleCommand id _ (cmd:arg:_))) = when (f `isUnqualifiedCommand` "exec") $ warn (id) 2093 $ "Remove \"exec \" if script should continue after this command." commentIfExec _ = return () prop_checkSpuriousExpansion1 = verify checkSpuriousExpansion "if $(true); then true; fi" prop_checkSpuriousExpansion2 = verify checkSpuriousExpansion "while \"$(cmd)\"; do :; done" prop_checkSpuriousExpansion3 = verifyNot checkSpuriousExpansion "$(cmd) --flag1 --flag2" prop_checkSpuriousExpansion4 = verify checkSpuriousExpansion "$((i++))" checkSpuriousExpansion (T_SimpleCommand _ _ [T_NormalWord _ [word]]) = check word where check word = case word of T_DollarExpansion id _ -> warn id 2091 "Remove surrounding $() to avoid executing output." T_Backticked id _ -> warn id 2092 "Remove backticks to avoid executing output." T_DollarArithmetic id _ -> err id 2084 "Remove '$' or use '_=$((expr))' to avoid executing output." T_DoubleQuoted id [subword] -> check subword _ -> return () checkSpuriousExpansion _ = return () prop_checkUnusedEchoEscapes1 = verify checkUnusedEchoEscapes "echo 'foo\\nbar\\n'" prop_checkUnusedEchoEscapes2 = verifyNot checkUnusedEchoEscapes "echo -e 'foi\\nbar'" prop_checkUnusedEchoEscapes3 = verify checkUnusedEchoEscapes "echo \"n:\\t42\"" prop_checkUnusedEchoEscapes4 = verifyNot checkUnusedEchoEscapes "echo lol" checkUnusedEchoEscapes = checkCommand "echo" f where isDashE = mkRegex "^-.*e" hasEscapes = mkRegex "\\\\[rnt]" f (arg:_) | (concat $ deadSimple arg) `matches` isDashE = return () f args = mapM_ checkEscapes args checkEscapes (T_NormalWord _ args) = mapM_ checkEscapes args checkEscapes (T_DoubleQuoted id args) = mapM_ checkEscapes args checkEscapes (T_Literal id str) = examine id str checkEscapes (T_SingleQuoted id str) = examine id str checkEscapes _ = return () examine id str = when (str `matches` hasEscapes) $ info id 2028 "echo won't expand escape sequences. Consider printf." prop_checkDollarBrackets1 = verify checkDollarBrackets "echo $[1+2]" prop_checkDollarBrackets2 = verifyNot checkDollarBrackets "echo $((1+2))" checkDollarBrackets (T_DollarBracket id _) = style id 2007 "Use $((..)) instead of deprecated $[..]" checkDollarBrackets _ = return () prop_checkSshHereDoc1 = verify checkSshHereDoc "ssh host << foo\necho $PATH\nfoo" prop_checkSshHereDoc2 = verifyNot checkSshHereDoc "ssh host << 'foo'\necho $PATH\nfoo" checkSshHereDoc (T_Redirecting _ redirs cmd) | cmd `isCommand` "ssh" = mapM_ checkHereDoc redirs where hasVariables = mkRegex "[`$]" checkHereDoc (T_FdRedirect _ _ (T_HereDoc id _ Unquoted token tokens)) | not (all isConstant tokens) = warn id 2087 $ "Quote '" ++ token ++ "' to make here document expansions happen on the server side rather than on the client." checkHereDoc _ = return () checkSshHereDoc _ = return () -- This is hard to get right without properly parsing ssh args prop_checkSshCmdStr1 = verify checkSshCommandString "ssh host \"echo $PS1\"" prop_checkSshCmdStr2 = verifyNot checkSshCommandString "ssh host \"ls foo\"" prop_checkSshCmdStr3 = verifyNot checkSshCommandString "ssh \"$host\"" checkSshCommandString = checkCommand "ssh" f where nonOptions args = filter (\x -> not $ "-" `isPrefixOf` (concat $ deadSimple x)) args f args = case nonOptions args of (hostport:r@(_:_)) -> checkArg $ last r _ -> return () checkArg (T_NormalWord _ [T_DoubleQuoted id parts]) = case filter (not . isConstant) parts of [] -> return () (x:_) -> info (getId x) 2029 $ "Note that, unescaped, this expands on the client side." checkArg _ = return () --- Subshell detection prop_subshellAssignmentCheck = verifyFull subshellAssignmentCheck "cat foo | while read bar; do a=$bar; done; echo \"$a\"" prop_subshellAssignmentCheck2 = verifyNotFull subshellAssignmentCheck "while read bar; do a=$bar; done < file; echo \"$a\"" prop_subshellAssignmentCheck3 = verifyFull subshellAssignmentCheck "( A=foo; ); rm $A" prop_subshellAssignmentCheck4 = verifyNotFull subshellAssignmentCheck "( A=foo; rm $A; )" prop_subshellAssignmentCheck5 = verifyFull subshellAssignmentCheck "cat foo | while read cow; do true; done; echo $cow;" prop_subshellAssignmentCheck6 = verifyFull subshellAssignmentCheck "( export lol=$(ls); ); echo $lol;" prop_subshellAssignmentCheck6a= verifyFull subshellAssignmentCheck "( typeset -a lol=a; ); echo $lol;" prop_subshellAssignmentCheck7 = verifyFull subshellAssignmentCheck "cmd | while read foo; do (( n++ )); done; echo \"$n lines\"" prop_subshellAssignmentCheck8 = verifyFull subshellAssignmentCheck "n=3 & echo $((n++))" prop_subshellAssignmentCheck9 = verifyFull subshellAssignmentCheck "read n & n=foo$n" prop_subshellAssignmentCheck10 = verifyFull subshellAssignmentCheck "(( n <<= 3 )) & (( n |= 4 )) &" prop_subshellAssignmentCheck11 = verifyFull subshellAssignmentCheck "cat /etc/passwd | while read line; do let n=n+1; done\necho $n" prop_subshellAssignmentCheck12 = verifyFull subshellAssignmentCheck "cat /etc/passwd | while read line; do let ++n; done\necho $n" subshellAssignmentCheck t = let flow = getVariableFlow t check = findSubshelled flow [("oops",[])] Map.empty in snd $ runState check [] data Scope = SubshellScope String | NoneScope deriving (Show, Eq) data StackData = StackScope Scope | StackScopeEnd -- (Base expression, specific position, var name, assigned values) | Assignment (Token, Token, String, DataSource) | Reference (Token, Token, String) deriving (Show, Eq) data DataSource = DataFrom [Token] | DataExternal deriving (Show, Eq) data VariableState = Dead Token String | Alive deriving (Show, Eq) leadType t = case t of T_DollarExpansion _ _ -> SubshellScope "$(..) expansion" T_Backticked _ _ -> SubshellScope "`..` expansion" T_Backgrounded _ _ -> SubshellScope "backgrounding &" T_Subshell _ _ -> SubshellScope "(..) group" -- This considers the whole pipeline one subshell. Consider fixing. T_Pipeline _ (_:_:[]) -> SubshellScope "pipeline" _ -> NoneScope getModifiedVariables t = case t of T_SimpleCommand _ vars [] -> concatMap (\x -> case x of T_Assignment id _ name _ w -> [(x, x, name, DataFrom [w])] _ -> [] ) vars c@(T_SimpleCommand _ _ _) -> getModifiedVariableCommand c TA_Unary _ "++|" (TA_Variable id name) -> [(t, t, name, DataFrom [t])] TA_Unary _ "|++" (TA_Variable id name) -> [(t, t, name, DataFrom [t])] TA_Binary _ op (TA_Variable id name) rhs -> if any (==op) ["=", "*=", "/=", "%=", "+=", "-=", "<<=", ">>=", "&=", "^=", "|="] then [(t, t, name, DataFrom [rhs])] else [] --Points to 'for' rather than variable T_ForIn id str words _ -> [(t, t, str, DataFrom words)] T_SelectIn id str words _ -> [(t, t, str, DataFrom words)] _ -> [] -- Consider 'export' a reference, since it makes the var available getReferencedVariableCommand base@(T_SimpleCommand _ _ ((T_NormalWord _ ((T_Literal _ x):_)):rest)) = case x of "export" -> concatMap getReference rest _ -> [] where getReference t@(T_Assignment _ _ name _ value) = [(t, t, name)] getReference t@(T_NormalWord _ [T_Literal _ name]) | not ("-" `isPrefixOf` name) = [(t, t, name)] getReference _ = [] getReferencedVariableCommand _ = [] getModifiedVariableCommand base@(T_SimpleCommand _ _ ((T_NormalWord _ ((T_Literal _ x):_)):rest)) = filter (\(_,_,s,_) -> not ("-" `isPrefixOf` s)) $ case x of "read" -> concatMap getLiteral rest "let" -> concatMap letParamToLiteral rest "export" -> concatMap getModifierParam rest "declare" -> concatMap getModifierParam rest "typeset" -> concatMap getModifierParam rest "local" -> concatMap getModifierParam rest _ -> [] where stripEquals s = let rest = dropWhile (/= '=') s in if rest == "" then "" else tail rest stripEqualsFrom (T_NormalWord id1 ((T_Literal id2 s):rs)) = (T_NormalWord id1 ((T_Literal id2 (stripEquals s)):rs)) stripEqualsFrom (T_NormalWord id1 [T_DoubleQuoted id2 [T_Literal id3 s]]) = (T_NormalWord id1 [T_DoubleQuoted id2 [T_Literal id3 (stripEquals s)]]) stripEqualsFrom t = t getLiteral t@(T_NormalWord _ [T_Literal _ s]) = [(base, t, s, DataExternal)] getLiteral t@(T_NormalWord _ [T_SingleQuoted _ s]) = [(base, t, s, DataExternal)] getLiteral t@(T_NormalWord _ [T_DoubleQuoted _ [T_Literal id s]]) = [(base, t, s, DataExternal)] getLiteral x = [] getModifierParam t@(T_Assignment _ _ name _ value) = [(base, t, name, DataFrom [value])] getModifierParam _ = [] letParamToLiteral token = if var == "" then [] else [(base, token, var, DataFrom [stripEqualsFrom token])] where var = takeWhile (isVariableChar) $ dropWhile (\x -> x `elem` "+-") $ concat $ deadSimple token getModifiedVariableCommand _ = [] -- TODO: getBracedReference s = takeWhile (\x -> not $ x `elem` ":[#%/^,") $ dropWhile (`elem` "#!") s getReferencedVariables t = case t of T_DollarBraced id l -> map (\x -> (t, t, x)) $ [getBracedReference $ bracedString l] TA_Variable id str -> [(t, t, str)] T_Assignment id Append str _ _ -> [(t, t, str)] x -> getReferencedVariableCommand x getVariableFlow t = let (_, stack) = runState (doStackAnalysis startScope endScope t) [] in reverse stack where startScope t = let scopeType = leadType t in do when (scopeType /= NoneScope) $ modify ((StackScope scopeType):) if assignFirst t then setWritten t else return () endScope t = let scopeType = leadType t in do setRead t if assignFirst t then return () else setWritten t when (scopeType /= NoneScope) $ modify ((StackScopeEnd):) assignFirst (T_ForIn _ _ _ _) = True assignFirst (T_SelectIn _ _ _ _) = True assignFirst _ = False setRead t = let read = getReferencedVariables t in mapM_ (\v -> modify ((Reference v):)) read setWritten t = let written = getModifiedVariables t in mapM_ (\v -> modify ((Assignment v):)) written findSubshelled [] _ _ = return () findSubshelled ((Assignment x@(_, _, str, _)):rest) ((reason,scope):lol) deadVars = findSubshelled rest ((reason, x:scope):lol) $ Map.insert str Alive deadVars findSubshelled ((Reference (_, readToken, str)):rest) scopes deadVars = do case Map.findWithDefault Alive str deadVars of Alive -> return () Dead writeToken reason -> do info (getId writeToken) 2030 $ "Modification of " ++ str ++ " is local (to subshell caused by "++ reason ++")." info (getId readToken) 2031 $ str ++ " was modified in a subshell. That change might be lost." findSubshelled rest scopes deadVars findSubshelled ((StackScope (SubshellScope reason)):rest) scopes deadVars = findSubshelled rest ((reason,[]):scopes) deadVars findSubshelled ((StackScopeEnd):rest) ((reason, scope):oldScopes) deadVars = findSubshelled rest oldScopes $ foldl (\m (_, token, var, _) -> Map.insert var (Dead token reason) m) deadVars scope doVariableFlowAnalysis readFunc writeFunc empty t = fst $ runState ( foldM (\list x -> do { l <- doFlow x; return $ l ++ list; }) [] flow ) empty where flow = getVariableFlow t doFlow (Reference (base, token, name)) = readFunc base token name doFlow (Assignment (base, token, name, values)) = writeFunc base token name values doFlow _ = return [] ---- Check whether variables could have spaces/globs prop_checkSpacefulness0 = verifyFull checkSpacefulness "for f in *.mp3; do echo $f; done" prop_checkSpacefulness1 = verifyFull checkSpacefulness "a='cow moo'; echo $a" prop_checkSpacefulness2 = verifyNotFull checkSpacefulness "a='cow moo'; [[ $a ]]" prop_checkSpacefulness3 = verifyNotFull checkSpacefulness "a='cow*.mp3'; echo \"$a\"" prop_checkSpacefulness4 = verifyFull checkSpacefulness "for f in *.mp3; do echo $f; done" prop_checkSpacefulness4a= verifyNotFull checkSpacefulness "foo=3; foo=$(echo $foo)" prop_checkSpacefulness5 = verifyFull checkSpacefulness "a='*'; b=$a; c=lol${b//foo/bar}; echo $c" prop_checkSpacefulness6 = verifyFull checkSpacefulness "a=foo$(lol); echo $a" prop_checkSpacefulness7 = verifyFull checkSpacefulness "a=foo\\ bar; rm $a" prop_checkSpacefulness8 = verifyNotFull checkSpacefulness "a=foo\\ bar; a=foo; rm $a" prop_checkSpacefulnessA = verifyFull checkSpacefulness "rm $1" prop_checkSpacefulnessB = verifyFull checkSpacefulness "rm ${10//foo/bar}" prop_checkSpacefulnessC = verifyNotFull checkSpacefulness "(( $1 + 3 ))" prop_checkSpacefulnessD = verifyNotFull checkSpacefulness "if [[ $2 -gt 14 ]]; then true; fi" prop_checkSpacefulnessE = verifyNotFull checkSpacefulness "foo=$3 env" prop_checkSpacefulnessF = verifyNotFull checkSpacefulness "local foo=$1" prop_checkSpacefulnessG = verifyNotFull checkSpacefulness "declare foo=$1" prop_checkSpacefulnessH = verifyFull checkSpacefulness "echo foo=$1" prop_checkSpacefulnessI = verifyNotFull checkSpacefulness "$1 --flags" prop_checkSpacefulnessJ = verifyFull checkSpacefulness "echo $PWD" checkSpacefulness t = doVariableFlowAnalysis readF writeF (Map.fromList defaults) t where defaults = zip variablesWithoutSpaces (repeat False) hasSpaces name = do map <- get return $ Map.findWithDefault True name map setSpaces name bool = do modify $ Map.insert name bool readF _ token name = do spaced <- hasSpaces name if spaced && (not $ "@" `isPrefixOf` name) -- There's another warning for this && (not $ isCounting token) && (not $ inUnquotableContext parents token) && (not $ usedAsCommandName parents token) then return [(getId token, Note InfoC 2086 warning)] else return [] where warning = "Double quote to prevent globbing and word splitting." writeF _ _ name DataExternal = do setSpaces name True return [] writeF _ _ name (DataFrom vals) = do map <- get setSpaces name (isSpacefulWord (\x -> Map.findWithDefault True x map) vals) return [] parents = getParentTree t isCounting (T_DollarBraced id token) = case concat $ deadSimple token of '#':_ -> True _ -> False isCounting _ = False isSpacefulWord :: (String -> Bool) -> [Token] -> Bool isSpacefulWord f words = any (isSpaceful f) words isSpaceful :: (String -> Bool) -> Token -> Bool isSpaceful spacefulF x = case x of T_DollarExpansion _ _ -> True T_Backticked _ _ -> True T_Glob _ _ -> True T_Extglob _ _ _ -> True T_Literal _ s -> s `containsAny` globspace T_SingleQuoted _ s -> s `containsAny` globspace T_DollarBraced _ l -> spacefulF $ getBracedReference $ bracedString l T_NormalWord _ w -> isSpacefulWord spacefulF w T_DoubleQuoted _ w -> isSpacefulWord spacefulF w _ -> False where globspace = "*? \t\n" containsAny s chars = any (\c -> c `elem` s) chars prop_checkQuotesInLiterals1 = verifyFull checkQuotesInLiterals "param='--foo=\"bar\"'; app $param" prop_checkQuotesInLiterals1a= verifyFull checkQuotesInLiterals "param=\"--foo='lolbar'\"; app $param" prop_checkQuotesInLiterals2 = verifyNotFull checkQuotesInLiterals "param='--foo=\"bar\"'; app \"$param\"" prop_checkQuotesInLiterals3 =verifyNotFull checkQuotesInLiterals "param=('--foo='); app \"${param[@]}\"" prop_checkQuotesInLiterals4 = verifyNotFull checkQuotesInLiterals "param=\"don't bother with this one\"; app $param" prop_checkQuotesInLiterals5 = verifyNotFull checkQuotesInLiterals "param=\"--foo='lolbar'\"; eval app $param" checkQuotesInLiterals t = doVariableFlowAnalysis readF writeF Map.empty t where getQuotes name = get >>= (return . Map.lookup name) setQuotes name ref = modify $ Map.insert name ref deleteQuotes = modify . Map.delete parents = getParentTree t quoteRegex = mkRegex "\"|([= ]|^)'|'( |$)" containsQuotes s = isJust $ matchRegex quoteRegex s -- Just catch the most blatant cases of foo='--cow="lol bert"'; cmd $foo, since that's 99% writeF _ _ name (DataFrom values) = do let quotedVars = filter (\v -> containsQuotes (concat $ deadSimple v)) values case quotedVars of [] -> deleteQuotes name x:_ -> setQuotes name (getId x) return [] writeF _ _ _ _ = return [] readF _ expr name = do assignment <- getQuotes name if isJust assignment && not (isParamTo parents "eval" expr) && not (inUnquotableContext parents expr) then return [ (fromJust assignment, Note WarningC 2089 "Word splitting will treat quotes as literals. Use an array."), (getId expr, Note WarningC 2090 "Embedded quotes in this variable will not be respected.") ] else return [] prop_checkFunctionsUsedExternally1 = verifyFull checkFunctionsUsedExternally "foo() { :; }; sudo foo" prop_checkFunctionsUsedExternally2 = verifyFull checkFunctionsUsedExternally "alias f='a'; xargs -n 1 f" prop_checkFunctionsUsedExternally3 = verifyNotFull checkFunctionsUsedExternally "f() { :; }; echo f" checkFunctionsUsedExternally t = runBasicAnalysis checkCommand t where invokingCmds = [ "chroot", "find", "screen", "ssh", "su", "sudo", "xargs" ] checkCommand t@(T_SimpleCommand _ _ (cmd:args)) = let name = fromMaybe "" $ getCommandBasename t in when (name `elem` invokingCmds) $ mapM_ (checkArg name) args checkCommand _ = return () functions = Map.fromList $ runBasicAnalysis findFunctions t findFunctions (T_Function id name _) = modify ((name, id):) findFunctions t@(T_SimpleCommand id _ (_:args)) | t `isUnqualifiedCommand` "alias" = mapM_ getAlias args findFunctions _ = return () getAlias arg = let string = concat $ deadSimple arg in when ('=' `elem` string) $ modify ((takeWhile (/= '=') string, getId arg):) checkArg cmd arg = case Map.lookup (concat $ deadSimple arg) functions of Nothing -> return () Just id -> do warn (getId arg) 2033 $ "Shell functions can't be passed to external commands." info id 2032 $ "Use own script or sh -c '..' to run this from " ++ cmd ++ "." prop_checkUnused0 = verifyNotFull checkUnusedAssignments "var=foo; echo $var" prop_checkUnused1 = verifyFull checkUnusedAssignments "var=foo; echo $bar" prop_checkUnused2 = verifyNotFull checkUnusedAssignments "var=foo; export var;" prop_checkUnused3 = verifyFull checkUnusedAssignments "for f in *; do echo '$f'; done" prop_checkUnused4 = verifyFull checkUnusedAssignments "local i=0" prop_checkUnused5 = verifyNotFull checkUnusedAssignments "read lol; echo $lol" prop_checkUnused6 = verifyNotFull checkUnusedAssignments "var=4; (( var++ ))" prop_checkUnused7 = verifyNotFull checkUnusedAssignments "var=2; $((var))" prop_checkUnused8 = verifyFull checkUnusedAssignments "var=2; var=3;" prop_checkUnused9 = verifyNotFull checkUnusedAssignments "read ''" prop_checkUnused10= verifyNotFull checkUnusedAssignments "read -p 'test: '" prop_checkUnused11= verifyNotFull checkUnusedAssignments "bar=5; export foo[$bar]=3" prop_checkUnused12= verifyNotFull checkUnusedAssignments "read foo; echo ${!foo}" checkUnusedAssignments t = snd $ runState (mapM_ checkAssignment flow) [] where flow = getVariableFlow t references = foldl (flip ($)) defaultMap (map insertRef flow) insertRef (Reference (base, token, name)) = Map.insert name () insertRef _ = id checkAssignment (Assignment (_, token, name, _)) | isVariableName name = case Map.lookup name references of Just _ -> return () Nothing -> do info (getId token) 2034 $ name ++ " appears unused. Verify it or export it." checkAssignment _ = return () defaultMap = Map.fromList $ zip internalVariables $ repeat () prop_checkGlobsAsOptions1 = verify checkGlobsAsOptions "rm *.txt" prop_checkGlobsAsOptions2 = verify checkGlobsAsOptions "ls ??.*" prop_checkGlobsAsOptions3 = verifyNot checkGlobsAsOptions "rm -- *.txt" checkGlobsAsOptions (T_SimpleCommand _ _ args) = mapM_ check $ takeWhile (not . isEndOfArgs) args where check v@(T_NormalWord _ ((T_Glob id s):_)) | s == "*" || s == "?" = info id 2035 $ "Use ./" ++ (concat $ deadSimple v) ++ " so names with dashes won't become options." check _ = return () isEndOfArgs t = case concat $ deadSimple t of "--" -> True ":::" -> True "::::" -> True _ -> False checkGlobsAsOptions _ = return () prop_checkWhileReadPitfalls1 = verify checkWhileReadPitfalls "while read foo; do ssh $foo uptime; done < file" prop_checkWhileReadPitfalls2 = verifyNot checkWhileReadPitfalls "while read -u 3 foo; do ssh $foo uptime; done 3< file" prop_checkWhileReadPitfalls3 = verifyNot checkWhileReadPitfalls "while true; do ssh host uptime; done" prop_checkWhileReadPitfalls4 = verifyNot checkWhileReadPitfalls "while read foo; do ssh $foo hostname < /dev/null; done" prop_checkWhileReadPitfalls5 = verifyNot checkWhileReadPitfalls "while read foo; do echo ls | ssh $foo; done" prop_checkWhileReadPitfalls6 = verifyNot checkWhileReadPitfalls "while read foo <&3; do ssh $foo; done 3< foo" checkWhileReadPitfalls (T_WhileExpression id [command] contents) | isStdinReadCommand command = do mapM_ checkMuncher contents where munchers = [ "ssh", "ffmpeg", "mplayer" ] isStdinReadCommand (T_Pipeline _ [T_Redirecting id redirs cmd]) = let plaintext = deadSimple cmd in head (plaintext ++ [""]) == "read" && (not $ "-u" `elem` plaintext) && all (not . stdinRedirect) redirs isStdinReadCommand _ = False checkMuncher (T_Pipeline _ ((T_Redirecting _ redirs cmd):_)) = do let name = fromMaybe "" $ getCommandBasename cmd when ((not . any stdinRedirect $ redirs) && (name `elem` munchers)) $ do info id 2095 $ name ++ " may swallow stdin, preventing this loop from working properly." warn (getId cmd) 2095 $ "Add < /dev/null to prevent " ++ name ++ " from swallowing stdin." checkMuncher _ = return () stdinRedirect (T_FdRedirect _ fd _) | fd == "" || fd == "0" = True stdinRedirect _ = False checkWhileReadPitfalls _ = return () prop_checkPrefixAssign1 = verifyTree checkPrefixAssignmentReference "var=foo echo $var" prop_checkPrefixAssign2 = verifyNotTree checkPrefixAssignmentReference "var=$(echo $var) cmd" checkPrefixAssignmentReference t@(T_DollarBraced id value) tree = check path where name = getBracedReference $ bracedString value path = getPath tree t idPath = map getId path check [] = return () check (t:rest) = case t of T_SimpleCommand _ vars (_:_) -> mapM_ checkVar vars otherwise -> check rest checkVar (T_Assignment aId mode aName Nothing value) | aName == name && (not $ aId `elem` idPath) = do warn aId 2097 "This assignment is only seen by the forked process." warn id 2098 "This expansion will not see the mentioned assignment." checkVar _ = return () checkPrefixAssignmentReference _ _ = return () prop_checkCharRangeGlob1 = verify checkCharRangeGlob "ls *[:digit:].jpg" prop_checkCharRangeGlob2 = verifyNot checkCharRangeGlob "ls *[[:digit:]].jpg" prop_checkCharRangeGlob3 = verify checkCharRangeGlob "ls [10-15]" prop_checkCharRangeGlob4 = verifyNot checkCharRangeGlob "ls [a-zA-Z]" checkCharRangeGlob (T_Glob id str) | isCharClass str = if ":" `isPrefixOf` contents && ":" `isSuffixOf` contents && contents /= ":" then warn id 2101 "Named class needs outer [], e.g. [[:digit:]]." else if (not $ '[' `elem` contents) && hasDupes then info id 2102 "Ranges can only match single chars (mentioned due to duplicates)." else return () where isCharClass str = "[" `isPrefixOf` str && "]" `isSuffixOf` str contents = drop 1 . take ((length str) - 1) $ str hasDupes = any (>1) . map length . group . sort . filter (/= '-') $ contents checkCharRangeGlob _ = return () prop_checkCdAndBack1 = verify (checkCdAndBack Sh) "for f in *; do cd $f; git pull; cd ..; done" prop_checkCdAndBack2 = verifyNot (checkCdAndBack Sh) "for f in *; do cd $f || continue; git pull; cd ..; done" prop_checkCdAndBack3 = verifyNot (checkCdAndBack Sh) "while [[ $PWD != / ]]; do cd ..; done" checkCdAndBack shell = doLists where doLists (T_ForIn _ _ _ cmds) = doList cmds doLists (T_WhileExpression _ _ cmds) = doList cmds doLists (T_UntilExpression _ _ cmds) = doList cmds doLists (T_IfExpression _ thens elses) = do mapM_ (\(_, l) -> doList l) thens doList elses doLists _ = return () isCdRevert t = case deadSimple t of ["cd", p] -> p `elem` ["..", "-"] _ -> False getCmd (T_Annotation id _ x) = getCmd x getCmd (T_Pipeline id [x]) = getCommandName x getCmd _ = Nothing doList list = let cds = filter ((== Just "cd") . getCmd) list in when (length cds >= 2 && isCdRevert (last cds)) $ warn (getId $ head cds) 2103 message message = if shell == Bash || shell == Zsh then "Consider using ( subshell ), 'cd foo||exit', or pushd/popd instead." else "Consider using ( subshell ) or 'cd foo||exit' instead."