{-
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 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 General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see .
-}
{-# LANGUAGE TemplateHaskell, FlexibleContexts #-}
module ShellCheck.Analytics (AnalysisOptions(..), defaultAnalysisOptions, filterByAnnotation, runAnalytics, shellForExecutable, runTests) where
import Control.Arrow (first)
import Control.Monad
import Control.Monad.State
import Control.Monad.Writer
import Data.Char
import Data.Functor
import Data.Function (on)
import Data.List
import Data.Maybe
import Data.Ord
import Debug.Trace
import ShellCheck.AST
import ShellCheck.Options
import ShellCheck.Data
import ShellCheck.Parser hiding (runTests)
import ShellCheck.Regex
import qualified Data.Map as Map
import Test.QuickCheck.All (forAllProperties)
import Test.QuickCheck.Test (quickCheckWithResult, stdArgs, maxSuccess)
data Parameters = Parameters {
variableFlow :: [StackData],
parentMap :: Map.Map Id Token,
shellType :: Shell,
shellTypeSpecified :: Bool
}
-- Checks that are run on the AST root
treeChecks :: [Parameters -> Token -> [Note]]
treeChecks = [
runNodeAnalysis
(\p t -> (mapM_ ((\ f -> f t) . (\ f -> f p))
(nodeChecks ++ checksFor (shellType p))))
,subshellAssignmentCheck
,checkSpacefulness
,checkQuotesInLiterals
,checkShebangParameters
,checkFunctionsUsedExternally
,checkUnusedAssignments
,checkUnpassedInFunctions
,checkArrayWithoutIndex
,checkShebang
,checkUnassignedReferences
]
checksFor Sh = [
checkBashisms
,checkTimeParameters
,checkForDecimals
]
checksFor Ksh = [
checkEchoSed
]
checksFor Bash = [
checkTimeParameters
,checkBraceExpansionVars
,checkEchoSed
,checkForDecimals
]
runAnalytics :: AnalysisOptions -> Token -> [Note]
runAnalytics options root = runList options root treeChecks
runList options root list = notes
where
params = Parameters {
shellType = fromMaybe (determineShell root) $ optionShellType options,
shellTypeSpecified = isJust $ optionShellType options,
parentMap = getParentTree root,
variableFlow = getVariableFlow (shellType params) (parentMap params) root
}
notes = filter (\c -> getCode c `notElem` optionExcludes options) $ concatMap (\f -> f params root) list
getCode (Note _ _ c _) = c
checkList l t = concatMap (\f -> f t) l
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
prop_determineShell3 = determineShell (T_Script (Id 0) "#!/bin/sh -e" []) == Sh
determineShell (T_Script _ shebang _) = fromMaybe Bash . shellForExecutable $ shellFor shebang
where shellFor s | "/env " `isInfixOf` s = head (drop 1 (words s)++[""])
shellFor s | ' ' `elem` s = shellFor $ takeWhile (/= ' ') s
shellFor s = reverse . takeWhile (/= '/') . reverse $ s
shellForExecutable "sh" = return Sh
shellForExecutable "ash" = return Sh
shellForExecutable "dash" = return Sh
shellForExecutable "ksh" = return Ksh
shellForExecutable "ksh88" = return Ksh
shellForExecutable "ksh93" = return Ksh
shellForExecutable "bash" = return Bash
shellForExecutable _ = Nothing
-- Checks that are run on each node in the AST
runNodeAnalysis f p t = execWriter (doAnalysis (f p) t)
nodeChecks :: [Parameters -> Token -> Writer [Note] ()]
nodeChecks = [
checkUuoc
,checkPipePitfalls
,checkForInQuoted
,checkForInLs
,checkShorthandIf
,checkDollarStar
,checkUnquotedDollarAt
,checkStderrRedirect
,checkUnquotedN
,checkNumberComparisons
,checkSingleBracketOperators
,checkDoubleBracketOperators
,checkNoaryWasBinary
,checkConstantNoary
,checkDivBeforeMult
,checkArithmeticDeref
,checkArithmeticBadOctal
,checkComparisonAgainstGlob
,checkPrintfVar
,checkCommarrays
,checkOrNeq
,checkEchoWc
,checkConstantIfs
,checkTr
,checkPipedAssignment
,checkAssignAteCommand
,checkUuoeCmd
,checkUuoeVar
,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
,checkUnquotedExpansions
,checkSingleQuotedVariables
,checkRedirectToSame
,checkPrefixAssignmentReference
,checkLoopKeywordScope
,checkCdAndBack
,checkWrongArithmeticAssignment
,checkConditionalAndOrs
,checkFunctionDeclarations
,checkCatastrophicRm
,checkInteractiveSu
,checkStderrPipe
,checkSetAssignment
,checkOverridingPath
,checkArrayAsString
,checkUnsupported
,checkMultipleAppends
,checkAliasesExpandEarly
,checkSuspiciousIFS
,checkAliasesUsesArgs
,checkShouldUseGrepQ
,checkTestGlobs
,checkConcatenatedDollarAt
,checkFindActionPrecedence
,checkTildeInPath
,checkFindExecWithSingleArgument
,checkReturn
,checkMaskedReturns
,checkInjectableFindSh
]
filterByAnnotation token =
filter (not . shouldIgnore)
where
numFor (Note _ _ code _) = code
idFor (Note id _ _ _) = id
shouldIgnore note =
any (shouldIgnoreFor (numFor note)) $
getPath parents (T_Bang $ idFor note)
shouldIgnoreFor num (T_Annotation _ anns _) =
any hasNum anns
where
hasNum (DisableComment ts) = num == ts
shouldIgnoreFor _ _ = False
parents = getParentTree token
addNote note = tell [note]
makeNote severity id code note = addNote $ Note id severity code note
warn = makeNote WarningC
err = makeNote ErrorC
info = makeNote InfoC
style = makeNote StyleC
isVariableStartChar x = x == '_' || isAsciiLower x || isAsciiUpper x
isVariableChar x = isVariableStartChar x || isDigit x
variableNameRegex = mkRegex "[_a-zA-Z][_a-zA-Z0-9]*"
prop_isVariableName1 = isVariableName "_fo123"
prop_isVariableName2 = not $ isVariableName "4"
prop_isVariableName3 = not $ isVariableName "test: "
isVariableName (x:r) = isVariableStartChar x && all isVariableChar r
isVariableName _ = False
potentially = fromMaybe (return ())
willSplit x =
case x of
T_DollarBraced {} -> True
T_DollarExpansion {} -> True
T_Backticked {} -> True
T_BraceExpansion {} -> 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
getSuspiciousRegexWildcard str =
if not $ str `matches` contra
then do
match <- matchRegex suspicious str
str <- match !!! 0
str !!! 0
else
fail "looks good"
where
suspicious = mkRegex "([A-Za-z1-9])\\*"
contra = mkRegex "[^a-zA-Z1-9]\\*|[][^$+\\\\]"
headOrDefault _ (a:_) = a
headOrDefault def _ = def
isConstant token =
case token of
T_NormalWord _ l -> all isConstant l
T_DoubleQuoted _ l -> all isConstant l
T_SingleQuoted _ _ -> True
T_Literal _ _ -> True
_ -> False
isEmpty token =
case token of
T_NormalWord _ l -> all isEmpty l
T_DoubleQuoted _ l -> all isEmpty l
T_SingleQuoted _ "" -> True
T_Literal _ "" -> True
_ -> False
makeSimple (T_NormalWord _ [f]) = f
makeSimple (T_Redirecting _ _ f) = f
makeSimple (T_Annotation _ _ f) = f
makeSimple t = t
simplify = doTransform makeSimple
deadSimple (T_NormalWord _ l) = [concat (concatMap deadSimple l)]
deadSimple (T_DoubleQuoted _ l) = [concat (concatMap deadSimple l)]
deadSimple (T_SingleQuoted _ s) = [s]
deadSimple (T_DollarBraced _ _) = ["${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
-- Workaround for let "foo = bar" parsing
deadSimple (TA_Sequence _ [TA_Expansion _ v]) = concatMap deadSimple v
deadSimple _ = []
-- Turn a SimpleCommand foo -avz --bar=baz into args ["a", "v", "z", "bar"]
getFlagsUntil stopCondition (T_SimpleCommand _ _ (_:args)) =
let textArgs = takeWhile (not . stopCondition . snd) $ map (\x -> (x, concat $ deadSimple x)) args in
concatMap flag textArgs
where
flag (x, ('-':'-':arg)) = [ (x, takeWhile (/= '=') arg) ]
flag (x, ('-':args)) = map (\v -> (x, [v])) args
flag _ = []
getFlagsUntil _ _ = error "Internal shellcheck error, please report! (getFlags on non-command)"
getAllFlags = getFlagsUntil (== "--")
getLeadingFlags = getFlagsUntil (not . ("-" `isPrefixOf`))
(!!!) list i =
case drop i list of
[] -> Nothing
(r:_) -> Just r
verify :: (Parameters -> Token -> Writer [Note] ()) -> String -> Bool
verify f s = checkNode f s == Just True
verifyNot :: (Parameters -> Token -> Writer [Note] ()) -> String -> Bool
verifyNot f s = checkNode f s == Just False
verifyTree :: (Parameters -> Token -> [Note]) -> String -> Bool
verifyTree f s = checkTree f s == Just True
verifyNotTree :: (Parameters -> Token -> [Note]) -> String -> Bool
verifyNotTree f s = checkTree f s == Just False
checkNode f = checkTree (runNodeAnalysis f)
checkTree f s = case parseShell defaultAnalysisOptions "-" s of
(ParseResult (Just (t, m)) _) -> Just . not . null $ runList defaultAnalysisOptions t [f]
_ -> Nothing
-- Copied from https://wiki.haskell.org/Edit_distance
dist :: Eq a => [a] -> [a] -> Int
dist a b
= last (if lab == 0 then mainDiag
else if lab > 0 then lowers !! (lab - 1)
else{- < 0 -} uppers !! (-1 - lab))
where mainDiag = oneDiag a b (head uppers) (-1 : head lowers)
uppers = eachDiag a b (mainDiag : uppers) -- upper diagonals
lowers = eachDiag b a (mainDiag : lowers) -- lower diagonals
eachDiag a [] diags = []
eachDiag a (bch:bs) (lastDiag:diags) = oneDiag a bs nextDiag lastDiag : eachDiag a bs diags
where nextDiag = head (tail diags)
oneDiag a b diagAbove diagBelow = thisdiag
where doDiag [] b nw n w = []
doDiag a [] nw n w = []
doDiag (ach:as) (bch:bs) nw n w = me : (doDiag as bs me (tail n) (tail w))
where me = if ach == bch then nw else 1 + min3 (head w) nw (head n)
firstelt = 1 + head diagBelow
thisdiag = firstelt : doDiag a b firstelt diagAbove (tail diagBelow)
lab = length a - length b
min3 x y z = if x < y then x else min y z
hasFloatingPoint params = shellType params == Ksh
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
-- This should have used backreferences, but TDFA doesn't support them
sedRe = mkRegex "^s(.)([^\n]*)g?$"
isSimpleSed s = fromMaybe False $ do
[first,rest] <- matchRegex sedRe s
let delimiters = filter (== (first !! 0)) rest
guard $ length delimiters == 2
return True
acmd = deadSimple a
bcmd = deadSimple b
checkIn s =
when (isSimpleSed s) $
style id 2001 "See if you can use ${variable//search/replace} instead."
checkEchoSed _ _ = return ()
prop_checkPipedAssignment1 = verify checkPipedAssignment "A=ls | grep foo"
prop_checkPipedAssignment2 = verifyNot checkPipedAssignment "A=foo cmd | grep foo"
prop_checkPipedAssignment3 = verifyNot checkPipedAssignment "A=foo"
checkPipedAssignment _ (T_Pipeline _ _ (T_Redirecting _ _ (T_SimpleCommand id (_:_) []):_:_)) =
warn id 2036 "If you wanted to assign the output of the pipeline, use a=$(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 = verify checkWrongArithmeticAssignment "i=i+1"
prop_checkWrongArit2 = verify checkWrongArithmeticAssignment "n=2; i=n*2"
checkWrongArithmeticAssignment params (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 . warn (getId val) 2100 $
"Use $((..)) for arithmetics, e.g. i=$((i " ++ op ++ " 2))"
where
regex = mkRegex "^([_a-zA-Z][_a-zA-Z0-9]*)([+*-]).+$"
references = foldl (flip ($)) Map.empty (map insertRef $ variableFlow params)
insertRef (Assignment (_, _, name, _)) =
Map.insert name ()
insertRef _ = Prelude.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
checkWrongArithmeticAssignment _ _ = 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 $var"
prop_checkUuoc5 = verifyNot checkUuoc "cat \"$@\""
checkUuoc _ (T_Pipeline _ _ (T_Redirecting _ _ cmd:_:_)) =
checkCommand "cat" (const f) cmd
where
f [word] = unless (mayBecomeMultipleArgs word) $
style (getId word) 2002 "Useless cat. Consider 'cmd < file | ..' or 'cmd file | ..' instead."
f _ = return ()
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)"
prop_checkNeedlessCommands4 = verifyNot checkNeedlessCommands "foo=$(expr foo \\< regex)"
checkNeedlessCommands _ cmd@(T_SimpleCommand id _ args) |
cmd `isCommand` "expr" && not (any (`elem` words) exceptions) =
style id 2003 "expr is antiquated. Consider rewriting this using $((..)), ${} or [[ ]]."
where
-- These operators are hard to replicate in POSIX
exceptions = [ ":", "<", ">", "<=", ">=" ]
words = mapMaybe getLiteralString args
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"
prop_checkPipePitfalls7 = verifyNot checkPipePitfalls "find . -printf '%s\\n' | xargs foo"
checkPipePitfalls _ (T_Pipeline id _ commands) = do
for ["find", "xargs"] $
\(find:xargs:_) ->
let args = deadSimple xargs ++ deadSimple find
in
unless (any ($ args) [
hasShortParameter '0',
hasParameter "null",
hasParameter "print0",
hasParameter "printf"
]) $ warn (getId find) 2038
"Use -print0/-0 or -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."
for' ["grep", "wc"] $
\x -> style x 2126 "Consider using grep -c instead of grep|wc."
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."
]
unless didLs $ do
for ["ls", "?"] $
\(ls:_) -> unless (hasShortParameter 'N' (deadSimple ls)) $
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 . (\ 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 char = any (\x -> "-" `isPrefixOf` x && char `elem` x)
hasParameter string =
any (isPrefixOf string . dropWhile (== '-'))
checkPipePitfalls _ _ = return ()
indexOfSublists sub = f 0
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
isArrayExpansion (T_DollarBraced _ l) =
let string = bracedString l in
"@" `isPrefixOf` string ||
not ("#" `isPrefixOf` string) && "[@]" `isInfixOf` string
isArrayExpansion _ = False
-- Is it certain that this arg will becomes multiple args?
willBecomeMultipleArgs t = willConcatInAssignment t || f t
where
f (T_Extglob {}) = True
f (T_Glob {}) = True
f (T_BraceExpansion {}) = True
f (T_DoubleQuoted _ parts) = any f parts
f (T_NormalWord _ parts) = any f parts
f _ = False
willConcatInAssignment t@(T_DollarBraced {}) = isArrayExpansion t
willConcatInAssignment (T_DoubleQuoted _ parts) = any willConcatInAssignment parts
willConcatInAssignment (T_NormalWord _ parts) = any willConcatInAssignment parts
willConcatInAssignment _ = False
-- Is it possible that this arg becomes multiple args?
mayBecomeMultipleArgs t = willBecomeMultipleArgs t || f t
where
f (T_DollarBraced _ l) =
let string = bracedString l in
"!" `isPrefixOf` string
f (T_DoubleQuoted _ parts) = any f parts
f (T_NormalWord _ parts) = any f parts
f _ = False
prop_checkShebangParameters1 = verifyTree checkShebangParameters "#!/usr/bin/env bash -x\necho cow"
prop_checkShebangParameters2 = verifyNotTree checkShebangParameters "#! /bin/sh -l "
checkShebangParameters _ (T_Script id sb _) =
[Note id ErrorC 2096 "On most OS, shebangs can only specify a single parameter." | length (words sb) > 2]
prop_checkShebang1 = verifyNotTree checkShebang "#!/usr/bin/env bash -x\necho cow"
prop_checkShebang2 = verifyNotTree checkShebang "#! /bin/sh -l "
prop_checkShebang3 = verifyTree checkShebang "ls -l"
checkShebang params (T_Script id sb _) =
[Note id ErrorC 2148 "Tips depend on target shell and yours is unknown. Add a shebang."
| not (shellTypeSpecified params) && sb == "" ]
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"
prop_checkBashisms19= verify checkBashisms "foo > file*.txt"
prop_checkBashisms20= verify checkBashisms "read -ra foo"
prop_checkBashisms21= verify checkBashisms "[ -a foo ]"
prop_checkBashisms22= verifyNot checkBashisms "[ foo -a bar ]"
prop_checkBashisms23= verify checkBashisms "trap mything err int"
prop_checkBashisms24= verifyNot checkBashisms "trap mything int term"
prop_checkBashisms25= verify checkBashisms "cat < /dev/tcp/host/123"
prop_checkBashisms26= verify checkBashisms "trap mything ERR SIGTERM"
checkBashisms _ = bashism
where
errMsg id s = err id 2040 $ "In sh, " ++ s ++ " not supported, even when sh is actually bash."
warnMsg id s = warn id 2039 $ "In POSIX sh, " ++ s ++ " not supported."
bashism (T_ProcSub id _ _) = errMsg id "process substitution is"
bashism (T_Extglob id _ _) = warnMsg id "extglob is"
bashism (T_DollarSingleQuoted id _) = warnMsg id "$'..' is"
bashism (T_DollarDoubleQuoted id _) = warnMsg id "$\"..\" is"
bashism (T_ForArithmetic id _ _ _ _) = warnMsg id "arithmetic for loops are"
bashism (T_Arithmetic id _) = warnMsg id "standalone ((..)) is"
bashism (T_DollarBracket id _) = warnMsg id "$[..] in place of $((..)) is"
bashism (T_SelectIn id _ _ _) = warnMsg id "select loops are"
bashism (T_BraceExpansion id _) = warnMsg id "brace expansion is"
bashism (T_Condition id DoubleBracket _) = warnMsg id "[[ ]] is"
bashism (T_HereString id _) = warnMsg id "here-strings are"
bashism (TC_Binary id SingleBracket op _ _)
| op `elem` [ "-nt", "-ef", "\\<", "\\>", "==" ] =
warnMsg id $ op ++ " is"
bashism (TC_Unary id _ "-a" _) =
warnMsg id "unary -a in place of -e is"
bashism (TA_Unary id op _)
| op `elem` [ "|++", "|--", "++|", "--|"] =
warnMsg id $ filter (/= '|') op ++ " is"
bashism (TA_Binary id "**" _ _) = warnMsg id "exponentials are"
bashism (T_FdRedirect id "&" (T_IoFile _ (T_Greater _) _)) = warnMsg id "&> is"
bashism (T_IoFile id _ word) | isNetworked =
warnMsg id "/dev/{tcp,udp} is"
where
file = onlyLiteralString word
isNetworked = any (`isPrefixOf` file) ["/dev/tcp", "/dev/udp"]
bashism t@(TA_Expansion id _) | isBashism =
warnMsg id $ fromJust str ++ " is"
where
str = getLiteralString t
isBashism = isJust str && fromJust str `elem` bashVars
bashism t@(T_DollarBraced id token) = do
mapM_ check expansion
when (var `elem` bashVars) $ warnMsg id $ var ++ " is"
where
str = concat $ deadSimple token
var = getBracedReference (bracedString token)
check (regex, feature) =
when (isJust $ matchRegex regex str) $ warnMsg id feature
bashism t@(T_Pipe id "|&") =
warnMsg id "|& in place of 2>&1 | is"
bashism (T_Array id _) =
warnMsg id "arrays are"
bashism (T_IoFile id _ t) | isGlob t =
warnMsg id "redirecting to/from globs is"
bashism (T_CoProc id _ _) =
warnMsg id "coproc is"
bashism t@(T_SimpleCommand _ _ (cmd:arg:_))
| t `isCommand` "echo" && "-" `isPrefixOf` argString =
unless ("--" `isPrefixOf` argString) $ -- echo "-------"
warnMsg (getId arg) "echo flags are"
where argString = concat $ deadSimple arg
bashism t@(T_SimpleCommand _ _ (cmd:arg:_))
| t `isCommand` "exec" && "-" `isPrefixOf` concat (deadSimple arg) =
warnMsg (getId arg) "exec flags are"
bashism t@(T_SimpleCommand id _ _)
| t `isCommand` "let" = warnMsg id "'let' is"
bashism t@(T_SimpleCommand id _ (cmd:rest)) =
let name = fromMaybe "" $ getCommandName t
flags = getLeadingFlags t
in do
when (name `elem` bashCommands) $ warnMsg id $ "'" ++ name ++ "' is"
potentially $ do
allowed <- Map.lookup name allowedFlags
(word, flag) <- listToMaybe $ filter (\x -> snd x `notElem` allowed) flags
return . warnMsg (getId word) $ name ++ " -" ++ flag ++ " is"
when (name == "source") $ warnMsg id "'source' in place of '.' is"
when (name == "trap") $
let
check token = potentially $ do
word <- liftM (map toLower) $ getLiteralString token
guard $ word `elem` ["err", "debug", "return"]
return $ warnMsg (getId token) $ "trapping " ++ word ++ " is"
in
mapM_ check (reverse rest)
where
bashCommands = [
"let", "caller", "builtin", "complete", "compgen", "declare", "dirs", "disown",
"enable", "mapfile", "readarray", "pushd", "popd", "shopt", "suspend", "type",
"typeset"
]
allowedFlags = Map.fromList [
("read", ["r"]),
("ulimit", ["f"]),
("echo", []),
("exec", [])
]
bashism _ = return ()
varChars="_0-9a-zA-Z"
expansion = let re = mkRegex in [
(re $ "^[" ++ varChars ++ "]+\\[.*\\]$", "array references are"),
(re $ "^![" ++ varChars ++ "]+\\[[*@]]$", "array key expansion is"),
(re $ "^![" ++ varChars ++ "]+[*@]$", "name matching prefixes are"),
(re $ "^[" ++ varChars ++ "]+:[^-=?+]", "string indexing is"),
(re $ "^[" ++ varChars ++ "]+(\\[.*\\])?/", "string replacement is")
]
bashVars = [
"RANDOM", "LINENO", "OSTYPE", "MACHTYPE", "HOSTTYPE", "HOSTNAME",
"DIRSTACK", "EUID", "UID", "SECONDS", "SHLVL", "PIPESTATUS", "SHELLOPTS"
]
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_checkForInQuoted4a = verifyNot checkForInQuoted "for f in foo{1,2,3}; do true; done"
prop_checkForInQuoted5 = verify checkForInQuoted "for f in ls; do true; done"
prop_checkForInQuoted6 = verifyNot checkForInQuoted "for f in \"${!arr}\"; do true; done"
checkForInQuoted _ (T_ForIn _ f [T_NormalWord _ [word@(T_DoubleQuoted id list)]] _) =
when (any (\x -> willSplit x && not (mayBecomeMultipleArgs x)) list
|| (liftM wouldHaveBeenGlob (getLiteralString word) == 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 unless ('{' `elem` s) $
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 _ = try
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 "Iterating over ls output is fragile. Use globs."
("find":_) -> warn id 2044 "For loops over find output are fragile. Use find -exec or a while read loop."
_ -> 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 $
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 =
when(shouldWarn x) $
info (getId x) 2014 "This will expand once before find runs, not per file found."
fromWord (T_NormalWord _ l) = l
fromWord _ = []
checkFindExec _ _ = return ()
prop_checkUnquotedExpansions1 = verify checkUnquotedExpansions "rm $(ls)"
prop_checkUnquotedExpansions1a= verify checkUnquotedExpansions "rm `ls`"
prop_checkUnquotedExpansions2 = verify checkUnquotedExpansions "rm foo$(date)"
prop_checkUnquotedExpansions3 = verify checkUnquotedExpansions "[ $(foo) == cow ]"
prop_checkUnquotedExpansions3a= verify checkUnquotedExpansions "[ ! $(foo) ]"
prop_checkUnquotedExpansions4 = verifyNot checkUnquotedExpansions "[[ $(foo) == cow ]]"
prop_checkUnquotedExpansions5 = verifyNot checkUnquotedExpansions "for f in $(cmd); do echo $f; done"
prop_checkUnquotedExpansions6 = verifyNot checkUnquotedExpansions "$(cmd)"
prop_checkUnquotedExpansions7 = verifyNot checkUnquotedExpansions "cat << foo\n$(ls)\nfoo"
checkUnquotedExpansions params =
check
where
check t@(T_DollarExpansion _ _) = examine t
check t@(T_Backticked _ _) = examine t
check _ = return ()
tree = parentMap params
examine t =
unless (isQuoteFree tree t || usedAsCommandName tree t) $
warn (getId t) 2046 "Quote this to prevent word splitting."
prop_checkRedirectToSame = verify checkRedirectToSame "cat foo > foo"
prop_checkRedirectToSame2 = verify checkRedirectToSame "cat lol | sed -e 's/a/b/g' > lol"
prop_checkRedirectToSame3 = verifyNot checkRedirectToSame "cat lol | sed -e 's/a/b/g' > foo.bar && mv foo.bar lol"
prop_checkRedirectToSame4 = verifyNot checkRedirectToSame "foo /dev/null > /dev/null"
prop_checkRedirectToSame5 = verifyNot checkRedirectToSame "foo > bar 2> bar"
checkRedirectToSame params s@(T_Pipeline _ _ list) =
mapM_ (\l -> (mapM_ (\x -> doAnalysis (checkOccurrences x) l) (getAllRedirs list))) list
where
note x = Note x InfoC 2094
"Make sure not to read and write the same file in the same pipeline."
checkOccurrences t@(T_NormalWord exceptId x) u@(T_NormalWord newId y) =
when (exceptId /= newId
&& x == y
&& not (isOutput t && isOutput u)
&& not (special t)) $ do
addNote $ note newId
addNote $ note exceptId
checkOccurrences _ _ = return ()
getAllRedirs = concatMap (\t ->
case t of
T_Redirecting _ ls _ -> concatMap getRedirs ls
_ -> [])
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 (parentMap params) 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"
prop_checkShorthandIf5 = verifyNot checkShorthandIf "foo && rm || printf b"
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", "return", "printf"])
isOk _ = False
checkShorthandIf _ _ = return ()
prop_checkDollarStar = verify checkDollarStar "for f in $*; do ..; done"
prop_checkDollarStar2 = verifyNot checkDollarStar "a=$*"
checkDollarStar p t@(T_NormalWord _ [T_DollarBraced id l])
| bracedString l == "*" =
unless isAssigned $
warn id 2048 "Use \"$@\" (with quotes) to prevent whitespace problems."
where
path = getPath (parentMap p) t
isAssigned = any isAssignment . take 2 $ path
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 ${foo/@/ at }"
prop_checkUnquotedDollarAt6 = verifyNot checkUnquotedDollarAt "a=$@"
prop_checkUnquotedDollarAt7 = verify checkUnquotedDollarAt "for f in ${var[@]}; do true; done"
prop_checkUnquotedDollarAt8 = verifyNot checkUnquotedDollarAt "echo \"${args[@]:+${args[@]}}\""
checkUnquotedDollarAt p word@(T_NormalWord _ parts) | not $ isStrictlyQuoteFree (parentMap p) word =
forM_ (take 1 $ filter isArrayExpansion parts) $ \x ->
err (getId x) 2068
"Double quote array expansions to avoid re-splitting elements."
checkUnquotedDollarAt _ _ = return ()
prop_checkConcatenatedDollarAt1 = verify checkConcatenatedDollarAt "echo \"foo$@\""
prop_checkConcatenatedDollarAt2 = verify checkConcatenatedDollarAt "echo ${arr[@]}lol"
prop_checkConcatenatedDollarAt3 = verify checkConcatenatedDollarAt "echo $a$@"
prop_checkConcatenatedDollarAt4 = verifyNot checkConcatenatedDollarAt "echo $@"
prop_checkConcatenatedDollarAt5 = verifyNot checkConcatenatedDollarAt "echo \"${arr[@]}\""
checkConcatenatedDollarAt p word@(T_NormalWord {})
| not $ isQuoteFree (parentMap p) word =
unless (null $ drop 1 parts) $
mapM_ for array
where
parts = getWordParts word
array = take 1 $ filter isArrayExpansion parts
for t = err (getId t) 2145 "Argument mixes string and array. Use * or separate argument."
checkConcatenatedDollarAt _ _ = return ()
prop_checkArrayAsString1 = verify checkArrayAsString "a=$@"
prop_checkArrayAsString2 = verify checkArrayAsString "a=\"${arr[@]}\""
prop_checkArrayAsString3 = verify checkArrayAsString "a=*.png"
prop_checkArrayAsString4 = verify checkArrayAsString "a={1..10}"
prop_checkArrayAsString5 = verifyNot checkArrayAsString "a='*.gif'"
prop_checkArrayAsString6 = verifyNot checkArrayAsString "a=$*"
prop_checkArrayAsString7 = verifyNot checkArrayAsString "a=( $@ )"
checkArrayAsString _ (T_Assignment id _ _ _ word) =
if willConcatInAssignment word
then
warn (getId word) 2124
"Assigning an array to a string! Assign as array, or use * instead of @ to concatenate."
else
when (willBecomeMultipleArgs word) $
warn (getId word) 2125
"Brace expansions and globs are literal in assignments. Quote it or use an array."
checkArrayAsString _ _ = return ()
prop_checkArrayWithoutIndex1 = verifyTree checkArrayWithoutIndex "foo=(a b); echo $foo"
prop_checkArrayWithoutIndex2 = verifyNotTree checkArrayWithoutIndex "foo='bar baz'; foo=($foo); echo ${foo[0]}"
prop_checkArrayWithoutIndex3 = verifyTree checkArrayWithoutIndex "coproc foo while true; do echo cow; done; echo $foo"
prop_checkArrayWithoutIndex4 = verifyTree checkArrayWithoutIndex "coproc tail -f log; echo $COPROC"
prop_checkArrayWithoutIndex5 = verifyTree checkArrayWithoutIndex "a[0]=foo; echo $a"
checkArrayWithoutIndex params _ =
concat $ doVariableFlowAnalysis readF writeF Map.empty (variableFlow params)
where
readF _ (T_DollarBraced id token) _ = do
map <- get
return . maybeToList $ do
name <- getLiteralString token
assignment <- Map.lookup name map
return [Note id WarningC 2128
"Expanding an array without an index only gives the first element."]
readF _ _ _ = return []
writeF _ t name (DataArray _) = do
modify (Map.insert name t)
return []
writeF _ expr name _ = do
if isIndexed expr
then modify (Map.insert name expr)
else modify (Map.delete name)
return []
isIndexed expr =
case expr of
T_Assignment _ _ _ (Just _) _ -> True
_ -> False
prop_checkStderrRedirect = verify checkStderrRedirect "test 2>&1 > cow"
prop_checkStderrRedirect2 = verifyNot checkStderrRedirect "test > cow 2>&1"
prop_checkStderrRedirect3 = verifyNot checkStderrRedirect "test 2>&1 > file | grep stderr"
prop_checkStderrRedirect4 = verifyNot checkStderrRedirect "errors=$(test 2>&1 > file)"
prop_checkStderrRedirect5 = verifyNot checkStderrRedirect "read < <(test 2>&1 > file)"
prop_checkStderrRedirect6 = verify checkStderrRedirect "foo | bar 2>&1 > /dev/null"
checkStderrRedirect params redir@(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
usesOutput t =
case t of
(T_Pipeline _ _ list) -> length list > 1 && not (isParentOf (parentMap params) (last list) redir)
(T_ProcSub {}) -> True
(T_DollarExpansion {}) -> True
(T_Backticked {}) -> True
_ -> False
isCaptured = any usesOutput $ getPath (parentMap params) redir
error = unless isCaptured $
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 = trace ("FAILURE " ++ show t)
prop_checkSingleQuotedVariables = verify checkSingleQuotedVariables "echo '$foo'"
prop_checkSingleQuotedVariables2 = verify checkSingleQuotedVariables "echo 'lol$1.jpg'"
prop_checkSingleQuotedVariables3 = verifyNot checkSingleQuotedVariables "sed 's/foo$/bar/'"
prop_checkSingleQuotedVariables3a= verify checkSingleQuotedVariables "sed 's/${foo}/bar/'"
prop_checkSingleQuotedVariables3b= verify checkSingleQuotedVariables "sed 's/$(echo cow)/bar/'"
prop_checkSingleQuotedVariables3c= verify checkSingleQuotedVariables "sed 's/$((1+foo))/bar/'"
prop_checkSingleQuotedVariables4 = verifyNot checkSingleQuotedVariables "awk '{print $1}'"
prop_checkSingleQuotedVariables5 = verifyNot checkSingleQuotedVariables "trap 'echo $SECONDS' EXIT"
prop_checkSingleQuotedVariables6 = verifyNot checkSingleQuotedVariables "sed -n '$p'"
prop_checkSingleQuotedVariables6a= verify checkSingleQuotedVariables "sed -n '$pattern'"
prop_checkSingleQuotedVariables7 = verifyNot checkSingleQuotedVariables "PS1='$PWD \\$ '"
prop_checkSingleQuotedVariables8 = verify checkSingleQuotedVariables "find . -exec echo '$1' {} +"
prop_checkSingleQuotedVariables9 = verifyNot checkSingleQuotedVariables "find . -exec awk '{print $1}' {} \\;"
prop_checkSingleQuotedVariables10= verify checkSingleQuotedVariables "echo '`pwd`'"
checkSingleQuotedVariables params t@(T_SingleQuoted id s) =
when (s `matches` re) $
if "sed" == commandName
then unless (s `matches` sedContra) showMessage
else unless isProbablyOk showMessage
where
parents = parentMap params
showMessage = info id 2016
"Expressions don't expand in single quotes, use double quotes for that."
commandName = fromMaybe "" $ do
cmd <- getClosestCommand parents t
name <- getCommandBasename cmd
if name == "find"
then return $ getFindCommand cmd
else return name
isProbablyOk =
any isOkAssignment (take 3 $ getPath parents t)
|| commandName `elem` [
"trap"
,"sh"
,"bash"
,"ksh"
,"zsh"
,"ssh"
,"xprop"
,"alias"
]
|| "awk" `isSuffixOf` commandName
|| "perl" `isPrefixOf` commandName
commonlyQuoted = ["PS1", "PS2", "PS3", "PS4", "PROMPT_COMMAND"]
isOkAssignment t =
case t of
T_Assignment _ _ name _ _ -> name `elem` commonlyQuoted
otherwise -> False
re = mkRegex "\\$[{(0-9a-zA-Z_]|`.*`"
sedContra = mkRegex "\\$[dpsaic]($|[^a-zA-Z])"
getFindCommand (T_SimpleCommand _ _ words) =
let list = map getLiteralString words
cmd = dropWhile (\x -> x /= Just "-exec" && x /= Just "-execdir") list
in
case cmd of
(flag:cmd:rest) -> fromMaybe "find" cmd
_ -> "find"
getFindCommand (T_Redirecting _ _ cmd) = getFindCommand cmd
getFindCommand _ = "find"
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 -eq $foo ]]"
prop_checkNumberComparisons7 = verifyNot checkNumberComparisons "[[ 3.14 == $foo ]]"
prop_checkNumberComparisons8 = verify checkNumberComparisons "[[ foo <= bar ]]"
prop_checkNumberComparisons9 = verify checkNumberComparisons "[ foo \\>= bar ]"
prop_checkNumberComparisons11= verify checkNumberComparisons "[[ $foo -eq 'N' ]]"
prop_checkNumberComparisons12= verify checkNumberComparisons "[ x$foo -gt x${N} ]"
checkNumberComparisons params (TC_Binary id typ op lhs rhs) = do
if isNum lhs && not (isNonNum rhs)
|| isNum rhs && not (isNonNum lhs)
then do
when (isLtGt op) $
err id 2071 $
op ++ " is for string comparisons. Use " ++ eqv op ++ " instead."
when (isLeGe op) $
err id 2071 $ op ++ " is not a valid operator. " ++
"Use " ++ eqv op ++ " ."
else do
when (isLeGe op || isLtGt op) $
mapM_ checkDecimals [lhs, rhs]
when (isLeGe op) $
err id 2122 $ op ++ " is not a valid operator. " ++
"Use '! a " ++ invert op ++ " b' instead."
when (op `elem` ["-lt", "-gt", "-le", "-ge", "-eq"]) $ do
mapM_ checkDecimals [lhs, rhs]
checkStrings [lhs, rhs]
where
isLtGt = flip elem ["<", "\\<", ">", "\\>"]
isLeGe = flip elem ["<=", "\\<=", ">=", "\\>="]
supportsDecimals = (shellType params) == Ksh
checkDecimals hs =
when (isFraction hs && not supportsDecimals) $
err (getId hs) 2072 decimalError
decimalError = "Decimals are not supported. " ++
"Either use integers only, or use bc or awk to compare."
checkStrings hs =
mapM_ stringError . take 1 . filter isNonNum $ hs
isNonNum t = fromMaybe False $ do
s <- getLiteralStringExt (const $ return "") t
return . not . all numChar $ s
numChar x = isDigit x || x `elem` "+-. "
stringError t = err (getId t) 2130 $
op ++ " is for integer comparisons. Use " ++ seqv op ++ " instead."
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"
esc = if typ == SingleBracket then "\\" else ""
seqv "-ge" = "! a " ++ esc ++ "< b"
seqv "-gt" = esc ++ ">"
seqv "-le" = "! a " ++ esc ++ "> b"
seqv "-lt" = esc ++ "<"
seqv "-eq" = "="
seqv "-ne" = "!="
seqv _ = "the string equivalent"
invert ('\\':s) = invert s
invert "<=" = ">"
invert ">=" = "<"
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_checkConditionalAndOrs1 = verify checkConditionalAndOrs "[ foo && bar ]"
prop_checkConditionalAndOrs2 = verify checkConditionalAndOrs "[[ foo -o bar ]]"
prop_checkConditionalAndOrs3 = verifyNot checkConditionalAndOrs "[[ foo || bar ]]"
checkConditionalAndOrs _ (TC_And id SingleBracket "&&" _ _) =
err id 2107 "You can't use && inside [..]. Use -a instead."
checkConditionalAndOrs _ (TC_And id DoubleBracket "-a" _ _) =
err id 2108 "In [[..]], use && instead of -a."
checkConditionalAndOrs _ (TC_Or id SingleBracket "||" _ _) =
err id 2109 "You can't use || inside [..]. Use -o instead."
checkConditionalAndOrs _ (TC_Or id DoubleBracket "-o" _ _) =
err id 2110 "In [[..]], use || instead of -o."
checkConditionalAndOrs _ _ = 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
when (isConfusedGlobRegex s) $
warn (getId rhs) 2049 "=~ is for regex. Use == for globs."
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", "=~", ">", "<", "="] =
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 =
err id 2078 "This expression is constant. Did you forget a $ somewhere?"
checkConstantNoary _ _ = return ()
prop_checkBraceExpansionVars1 = verify checkBraceExpansionVars "echo {1..$n}"
prop_checkBraceExpansionVars2 = verifyNot checkBraceExpansionVars "echo {1,3,$n}"
checkBraceExpansionVars _ (T_BraceExpansion id list) = mapM_ check list
where
check element =
when ("..$" `isInfixOf` toString element) $
warn id 2051 "Bash doesn't support variables in brace range expansions."
literalExt t =
case t of
T_DollarBraced {} -> return "$"
T_DollarExpansion {} -> return "$"
T_DollarArithmetic {} -> return "$"
otherwise -> return "-"
toString t = fromJust $ getLiteralStringExt literalExt t
checkBraceExpansionVars _ _ = return ()
prop_checkForDecimals = verify checkForDecimals "((3.14*c))"
checkForDecimals _ t@(TA_Expansion id _) = potentially $ do
str <- getLiteralString t
first <- str !!! 0
guard $ isDigit first && '.' `elem` str
return $ 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))"
prop_checkDivBeforeMult3 = verifyNot checkDivBeforeMult "echo $((c/10*10))"
checkDivBeforeMult params (TA_Binary _ "*" (TA_Binary id "/" _ x) y)
| not (hasFloatingPoint params) && x /= y =
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 "(($1))"
prop_checkArithmeticDeref6 = verify checkArithmeticDeref "(( a[$i] ))"
prop_checkArithmeticDeref7 = verifyNot checkArithmeticDeref "(( 10#$n ))"
prop_checkArithmeticDeref8 = verifyNot checkArithmeticDeref "let i=$i+1"
prop_checkArithmeticDeref9 = verifyNot checkArithmeticDeref "(( a[foo] ))"
prop_checkArithmeticDeref10= verifyNot checkArithmeticDeref "(( a[\\$foo] ))"
prop_checkArithmeticDeref11= verifyNot checkArithmeticDeref "a[$foo]=wee"
prop_checkArithmeticDeref12= verify checkArithmeticDeref "for ((i=0; $i < 3; i)); do true; done"
prop_checkArithmeticDeref13= verifyNot checkArithmeticDeref "(( $$ ))"
checkArithmeticDeref params t@(TA_Expansion _ [T_DollarBraced id l]) =
unless (isException $ bracedString l) getWarning
where
isException [] = True
isException s = any (`elem` "/.:#%?*@$") s || isDigit (head s)
getWarning = fromMaybe noWarning . msum . map warningFor $ parents params t
warningFor t =
case t of
T_Arithmetic {} -> return normalWarning
T_DollarArithmetic {} -> return normalWarning
T_ForArithmetic {} -> return normalWarning
TA_Index {} -> return indexWarning
T_SimpleCommand {} -> return noWarning
_ -> Nothing
normalWarning = style id 2004 "$/${} is unnecessary on arithmetic variables."
indexWarning = style id 2149 "Remove $/${} for numeric index, or escape it for string."
noWarning = return ()
checkArithmeticDeref _ _ = return ()
prop_checkArithmeticBadOctal1 = verify checkArithmeticBadOctal "(( 0192 ))"
prop_checkArithmeticBadOctal2 = verifyNot checkArithmeticBadOctal "(( 0x192 ))"
prop_checkArithmeticBadOctal3 = verifyNot checkArithmeticBadOctal "(( 1 ^ 0777 ))"
checkArithmeticBadOctal _ t@(TA_Expansion id _) = potentially $ do
str <- getLiteralString t
guard $ str `matches` octalRE
return $ err id 2080 "Numbers with leading 0 are considered octal."
where
octalRE = mkRegex "^0[0-7]*[8-9]"
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 ]"
prop_checkComparisonAgainstGlob5 = verify checkComparisonAgainstGlob "[[ $cow != $bar ]]"
checkComparisonAgainstGlob _ (TC_Binary _ DoubleBracket op _ (T_NormalWord id [T_DollarBraced _ _]))
| op `elem` ["=", "==", "!="] =
warn id 2053 $ "Quote the rhs of " ++ op ++ " in [[ ]] to prevent glob matching."
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)"
prop_checkCommarrays4 = verifyNot checkCommarrays "cow=('one,' 'two')"
prop_checkCommarrays5 = verify checkCommarrays "a=([a]=b, [c]=d)"
prop_checkCommarrays6 = verify checkCommarrays "a=([a]=b,[c]=d,[e]=f)"
checkCommarrays _ (T_Array id l) =
when (any (isCommaSeparated . literal) l) $
warn id 2054 "Use spaces, not commas, to separate array elements."
where
literal (T_IndexedElement _ _ l) = literal l
literal (T_NormalWord _ l) = concatMap literal l
literal (T_Literal _ str) = str
literal _ = "str"
isCommaSeparated str = "," `isSuffixOf` str || length (filter (== ',') str) > 1
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 ()
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 _ _)
| s `notElem` ["-nt", "-ot", "-ef", "==", "!=", "<=", ">=", "-eq", "-ne", "-lt", "-le", "-gt", "-ge", "=~", ">", "<", "=", "\\<", "\\>", "\\<=", "\\>="] =
warn id 2057 "Unknown binary operator."
checkValidCondOps _ (TC_Unary id _ s _)
| s `notElem` [ "!", "-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 (first ((:) t))
post t = do
(_:rest, map) <- get
case rest of [] -> put (rest, map)
(x:_) -> put (rest, Map.insert (getId t) x map)
getTokenMap t =
execState (doAnalysis f t) Map.empty
where
f t = modify (Map.insert (getId t) t)
-- Is this node self quoting for a regular element?
isQuoteFree = isQuoteFreeNode False
-- Is this node striclty self quoting, for array expansions
isStrictlyQuoteFree = isQuoteFreeNode True
isQuoteFreeNode strict tree t =
(isQuoteFreeElement t == Just True) ||
head (mapMaybe isQuoteFreeContext (drop 1 $ getPath tree t) ++ [False])
where
-- Is this node self-quoting in itself?
isQuoteFreeElement t =
case t of
T_Assignment {} -> return True
_ -> Nothing
-- Are any subnodes inherently self-quoting?
isQuoteFreeContext t =
case t of
TC_Noary _ DoubleBracket _ -> return True
TC_Unary _ DoubleBracket _ _ -> return True
TC_Binary _ DoubleBracket _ _ _ -> return True
TA_Sequence {} -> return True
T_Arithmetic {} -> return True
T_Assignment {} -> return True
T_Redirecting {} -> return $
if strict then False else
-- Not true, just a hack to prevent warning about non-expansion refs
any (isCommand t) ["local", "declare", "typeset", "export", "trap", "readonly"]
T_DoubleQuoted _ _ -> return True
T_DollarDoubleQuoted _ _ -> return True
T_CaseExpression {} -> return True
T_HereDoc {} -> return True
T_DollarBraced {} -> return True
-- When non-strict, pragmatically assume it's desirable to split here
T_ForIn {} -> return (not strict)
T_SelectIn {} -> return (not strict)
_ -> Nothing
isParamTo tree cmd =
go
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
isParentOf tree parent child =
elem (getId parent) . map getId $ getPath tree child
parents params = getPath (parentMap params)
--- Command specific checks
checkCommand str f t@(T_SimpleCommand id _ (cmd:rest)) =
when (t `isCommand` str) $ f cmd rest
checkCommand _ _ _ = return ()
checkUnqualifiedCommand str f t@(T_SimpleCommand id _ (cmd:rest)) =
when (t `isUnqualifiedCommand` str) $ f cmd rest
checkUnqualifiedCommand _ _ _ = return ()
getLiteralString = getLiteralStringExt (const Nothing)
getGlobOrLiteralString = getLiteralStringExt f
where
f (T_Glob _ str) = return str
f _ = Nothing
getLiteralStringExt more = g
where
allInList = liftM concat . mapM g
g (T_DoubleQuoted _ l) = allInList l
g (T_DollarDoubleQuoted _ l) = allInList l
g (T_NormalWord _ l) = allInList l
g (TA_Expansion _ l) = allInList l
g (T_SingleQuoted _ s) = return s
g (T_Literal _ s) = return s
g x = more x
isLiteral t = isJust $ getLiteralString t
-- Get a literal string ignoring all non-literals
onlyLiteralString :: Token -> String
onlyLiteralString = fromJust . getLiteralStringExt (const $ return "")
-- Turn a NormalWord like foo="bar $baz" into a series of constituent elements like [foo=,bar ,$baz]
getWordParts (T_NormalWord _ l) = concatMap getWordParts l
getWordParts (T_DoubleQuoted _ l) = l
getWordParts other = [other]
getUnquotedLiteral (T_NormalWord _ list) =
liftM concat $ mapM str list
where
str (T_Literal _ s) = return s
str _ = Nothing
getUnquotedLiteral _ = Nothing
-- Return a list of NormalWords resulting from brace expansion
braceExpand (T_NormalWord id list) = take 1000 $ do
items <- mapM part list
return $ T_NormalWord id items
where
part (T_BraceExpansion id items) = do
item <- items
braceExpand item
part x = return x
isCommand token str = isCommandMatch token (\cmd -> cmd == str || ('/' : str) `isSuffixOf` cmd)
isUnqualifiedCommand token str = isCommandMatch token (== 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 (T_Assignment {}) = 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" (const f) where
f (dashv:var:rest) | getLiteralString dashv == Just "-v" = f rest
f (format:params) = check format
f _ = return ()
check format =
unless ('%' `elem` concat (deadSimple format) || isLiteral format) $
warn (getId format) 2059
"Don't use variables in the printf format string. Use printf \"..%s..\" \"$foo\"."
prop_checkUuoeCmd1 = verify checkUuoeCmd "echo $(date)"
prop_checkUuoeCmd2 = verify checkUuoeCmd "echo `date`"
prop_checkUuoeCmd3 = verify checkUuoeCmd "echo \"$(date)\""
prop_checkUuoeCmd4 = verify checkUuoeCmd "echo \"`date`\""
prop_checkUuoeCmd5 = verifyNot checkUuoeCmd "echo \"The time is $(date)\""
checkUuoeCmd _ = checkUnqualifiedCommand "echo" (const f) where
msg id = style id 2005 "Useless echo? Instead of 'echo $(cmd)', just use 'cmd'."
f [token] = when (tokenIsJustCommandOutput token) $ msg (getId token)
f _ = return ()
-- Check whether a word is entirely output from a single command
tokenIsJustCommandOutput t = case t of
T_NormalWord id [T_DollarExpansion _ _] -> True
T_NormalWord id [T_DoubleQuoted _ [T_DollarExpansion _ _]] -> True
T_NormalWord id [T_Backticked _ _] -> True
T_NormalWord id [T_DoubleQuoted _ [T_Backticked _ _]] -> True
_ -> False
prop_checkUuoeVar1 = verify checkUuoeVar "for f in $(echo $tmp); do echo lol; done"
prop_checkUuoeVar2 = verify checkUuoeVar "date +`echo \"$format\"`"
prop_checkUuoeVar3 = verifyNot checkUuoeVar "foo \"$(echo -e '\r')\""
prop_checkUuoeVar4 = verifyNot checkUuoeVar "echo $tmp"
prop_checkUuoeVar5 = verify checkUuoeVar "foo \"$(echo \"$(date) value:\" $value)\""
prop_checkUuoeVar6 = verifyNot checkUuoeVar "foo \"$(echo files: *.png)\""
prop_checkUuoeVar7 = verifyNot checkUuoeVar "foo $(echo $(bar))" -- covered by 2005
prop_checkUuoeVar8 = verifyNot checkUuoeVar "#!/bin/sh\nz=$(echo)"
checkUuoeVar _ p =
case p of
T_Backticked id [cmd] -> check id cmd
T_DollarExpansion id [cmd] -> check id cmd
_ -> return ()
where
couldBeOptimized f = case f of
T_Glob {} -> False
T_Extglob {} -> False
T_BraceExpansion {} -> False
T_NormalWord _ l -> all couldBeOptimized l
T_DoubleQuoted _ l -> all couldBeOptimized l
_ -> True
check id (T_Pipeline _ _ [T_Redirecting _ _ c]) = warnForEcho id c
check _ _ = return ()
isCovered first rest = null rest && tokenIsJustCommandOutput first
warnForEcho id = checkUnqualifiedCommand "echo" $ \_ vars ->
case vars of
(first:rest) ->
unless (isCovered first rest || "-" `isPrefixOf` onlyLiteralString first) $
when (all couldBeOptimized vars) $ style id 2116
"Useless echo? Instead of 'cmd $(echo foo)', just use 'cmd foo'."
otherwise -> 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" (const $ mapM_ f)
where
f w | isGlob w = -- 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) && ('*' `notElem` 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 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" (const 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"
prop_checkGrepRe10= verifyNot checkGrepRe "grep '^aa*' file"
prop_checkGrepRe11= verifyNot checkGrepRe "grep --include=*.png foo"
checkGrepRe _ = checkCommand "grep" (const 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 (getLiteralStringExt (const $ return "_") x) = f r
f (re:_) = do
when (isGlob re) $
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 potentially $ do
char <- getSuspiciousRegexWildcard string
return $ info (getId re) 2022 $
"Note that unlike globs, " ++ [char] ++ "* here matches '" ++ [char, char, char] ++ "' but not '" ++ wordStartingWith char ++ "'."
wordStartingWith c =
head . filter ([c] `isPrefixOf`) $ candidates
where
candidates =
sampleWords ++ map (\(x:r) -> toUpper x : r) sampleWords ++ [c:"test"]
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" (const 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 cmd (x:_) = let s = concat $ deadSimple x in
when ("-" `isPrefixOf` s && s /= "-p") $
info (getId cmd) 2023 "The shell may override 'time' as seen in man time(1). Use 'command time ..' for that one."
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_checkReturn1 = verifyNot checkReturn "return"
prop_checkReturn2 = verifyNot checkReturn "return 1"
prop_checkReturn3 = verifyNot checkReturn "return $var"
prop_checkReturn4 = verifyNot checkReturn "return $((a|b))"
prop_checkReturn5 = verify checkReturn "return -1"
prop_checkReturn6 = verify checkReturn "return 1000"
prop_checkReturn7 = verify checkReturn "return 'hello world'"
checkReturn _ = checkCommand "return" (const f)
where
f (first:second:_) =
err (getId second) 2151
"Only one integer 0-255 can be returned. Use stdout for other data."
f [value] =
when (isInvalid $ literal value) $
err (getId value) 2152
"Can only return 0-255. Other data should be written to stdout."
f _ = return ()
isInvalid s = s == "" || any (not . isDigit) s || length s > 5
|| let value = (read s :: Integer) in value > 255
literal token = fromJust $ getLiteralStringExt lit token
lit (T_DollarBraced {}) = return "0"
lit (T_DollarArithmetic {}) = return "0"
lit (T_DollarExpansion {}) = return "0"
lit (T_Backticked {}) = return "0"
lit _ = return "WTF"
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 $(..) instead of legacy `..`."
checkBackticks _ _ = return ()
prop_checkIndirectExpansion1 = verify checkIndirectExpansion "${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 arrays, ${!name} or (for sh only) eval."
where
isIndirection vars =
let list = mapMaybe isIndirectionPart vars in
not (null list) && and list
isIndirectionPart t =
case t of T_DollarExpansion _ _ -> Just True
T_Backticked _ _ -> Just True
T_DollarBraced _ _ -> Just True
T_DollarArithmetic _ _ -> Just True
T_Literal _ s -> if all isVariableChar s
then Nothing
else Just False
_ -> Just False
checkIndirectExpansion _ _ = return ()
prop_checkInexplicablyUnquoted1 = verify checkInexplicablyUnquoted "echo 'var='value';'"
prop_checkInexplicablyUnquoted2 = verifyNot checkInexplicablyUnquoted "'foo'*"
prop_checkInexplicablyUnquoted3 = verifyNot checkInexplicablyUnquoted "wget --user-agent='something'"
prop_checkInexplicablyUnquoted4 = verify checkInexplicablyUnquoted "echo \"VALUES (\"id\")\""
prop_checkInexplicablyUnquoted5 = verifyNot checkInexplicablyUnquoted "\"$dir\"/\"$file\""
prop_checkInexplicablyUnquoted6 = verifyNot checkInexplicablyUnquoted "\"$dir\"some_stuff\"$file\""
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 _ a:trapped:T_DoubleQuoted _ b:_) =
case trapped of
T_DollarExpansion id _ -> warnAboutExpansion id
T_DollarBraced id _ -> warnAboutExpansion id
T_Literal id s ->
unless (quotesSingleThing a && quotesSingleThing b) $
warnAboutLiteral id
_ -> return ()
check _ = return ()
-- If the surrounding quotes quote single things, like "$foo"_and_then_some_"$stuff",
-- the quotes were probably intentional and harmless.
quotesSingleThing x = case x of
[T_DollarExpansion _ _] -> True
[T_DollarBraced _ _] -> True
[T_Backticked _ _] -> True
_ -> False
warnAboutExpansion id =
warn id 2027 "The surrounding quotes actually unquote this. Remove or escape them."
warnAboutLiteral id =
warn id 2140 "The double quotes around this do nothing. Remove or escape them."
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 "Tilde does not expand in quotes. Use $HOME."
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_ForArithmetic _ _ _ _ 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"
prop_checkUnusedEchoEscapes5 = verifyNot checkUnusedEchoEscapes "echo -n -e '\n'"
checkUnusedEchoEscapes _ = checkCommand "echo" (const f)
where
isDashE = mkRegex "^-.*e"
hasEscapes = mkRegex "\\\\[rnt]"
f args | concat (concatMap deadSimple allButLast) `matches` isDashE =
return ()
where allButLast = reverse . drop 1 . reverse $ args
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" (const f)
where
nonOptions =
filter (\x -> not $ "-" `isPrefixOf` concat (deadSimple x))
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 = verifyTree subshellAssignmentCheck "cat foo | while read bar; do a=$bar; done; echo \"$a\""
prop_subshellAssignmentCheck2 = verifyNotTree subshellAssignmentCheck "while read bar; do a=$bar; done < file; echo \"$a\""
prop_subshellAssignmentCheck3 = verifyTree subshellAssignmentCheck "( A=foo; ); rm $A"
prop_subshellAssignmentCheck4 = verifyNotTree subshellAssignmentCheck "( A=foo; rm $A; )"
prop_subshellAssignmentCheck5 = verifyTree subshellAssignmentCheck "cat foo | while read cow; do true; done; echo $cow;"
prop_subshellAssignmentCheck6 = verifyTree subshellAssignmentCheck "( export lol=$(ls); ); echo $lol;"
prop_subshellAssignmentCheck6a= verifyTree subshellAssignmentCheck "( typeset -a lol=a; ); echo $lol;"
prop_subshellAssignmentCheck7 = verifyTree subshellAssignmentCheck "cmd | while read foo; do (( n++ )); done; echo \"$n lines\""
prop_subshellAssignmentCheck8 = verifyTree subshellAssignmentCheck "n=3 & echo $((n++))"
prop_subshellAssignmentCheck9 = verifyTree subshellAssignmentCheck "read n & n=foo$n"
prop_subshellAssignmentCheck10 = verifyTree subshellAssignmentCheck "(( n <<= 3 )) & (( n |= 4 )) &"
prop_subshellAssignmentCheck11 = verifyTree subshellAssignmentCheck "cat /etc/passwd | while read line; do let n=n+1; done\necho $n"
prop_subshellAssignmentCheck12 = verifyTree subshellAssignmentCheck "cat /etc/passwd | while read line; do let ++n; done\necho $n"
prop_subshellAssignmentCheck13 = verifyTree subshellAssignmentCheck "#!/bin/bash\necho foo | read bar; echo $bar"
prop_subshellAssignmentCheck14 = verifyNotTree subshellAssignmentCheck "#!/bin/ksh93\necho foo | read bar; echo $bar"
prop_subshellAssignmentCheck15 = verifyNotTree subshellAssignmentCheck "#!/bin/ksh\ncat foo | while read bar; do a=$bar; done\necho \"$a\""
prop_subshellAssignmentCheck16 = verifyNotTree subshellAssignmentCheck "(set -e); echo $@"
subshellAssignmentCheck params t =
let flow = variableFlow params
check = findSubshelled flow [("oops",[])] Map.empty
in snd $ runWriter 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, DataType)
| Reference (Token, Token, String)
deriving (Show)
data DataType = DataString DataSource | DataArray DataSource
deriving (Show)
data DataSource = SourceFrom [Token] | SourceExternal | SourceDeclaration
deriving (Show)
data VariableState = Dead Token String | Alive deriving (Show)
dataTypeFrom defaultType v = (case v of T_Array {} -> DataArray; _ -> defaultType) $ SourceFrom [v]
leadType shell parents t =
case t of
T_DollarExpansion _ _ -> SubshellScope "$(..) expansion"
T_Backticked _ _ -> SubshellScope "`..` expansion"
T_Backgrounded _ _ -> SubshellScope "backgrounding &"
T_Subshell _ _ -> SubshellScope "(..) group"
T_CoProcBody _ _ -> SubshellScope "coproc"
T_Redirecting {} ->
if fromMaybe False causesSubshell
then SubshellScope "pipeline"
else NoneScope
_ -> NoneScope
where
parentPipeline = do
parent <- Map.lookup (getId t) parents
case parent of
T_Pipeline {} -> return parent
_ -> Nothing
causesSubshell = do
(T_Pipeline _ _ list) <- parentPipeline
if length list <= 1
then return False
else if lastCreatesSubshell
then return True
else return . not $ (getId . head $ reverse list) == getId t
lastCreatesSubshell =
case shell of
Bash -> True
Sh -> True
Ksh -> False
getModifiedVariables t =
case t of
T_SimpleCommand _ vars [] ->
concatMap (\x -> case x of
T_Assignment id _ name _ w ->
[(x, x, name, dataTypeFrom DataString w)]
_ -> []
) vars
c@(T_SimpleCommand {}) ->
getModifiedVariableCommand c
TA_Unary _ "++|" var -> maybeToList $ do
name <- getLiteralString var
return (t, t, name, DataString $ SourceFrom [t])
TA_Unary _ "|++" var -> maybeToList $ do
name <- getLiteralString var
return (t, t, name, DataString $ SourceFrom [t])
TA_Binary _ op lhs rhs -> maybeToList $ do
guard $ op `elem` ["=", "*=", "/=", "%=", "+=", "-=", "<<=", ">>=", "&=", "^=", "|="]
name <- getLiteralString lhs
return (t, t, name, DataString $ SourceFrom [rhs])
t@(T_CoProc _ name _) ->
[(t, t, fromMaybe "COPROC" name, DataArray SourceExternal)]
--Points to 'for' rather than variable
T_ForIn id str words _ -> [(t, t, str, DataString $ SourceFrom words)]
T_SelectIn id str words _ -> [(t, t, str, DataString $ SourceFrom words)]
_ -> []
-- Consider 'export/declare -x' a reference, since it makes the var available
getReferencedVariableCommand base@(T_SimpleCommand _ _ (T_NormalWord _ (T_Literal _ x:_):rest)) =
case x of
"export" -> if "f" `elem` flags
then []
else concatMap getReference rest
"declare" -> if "x" `elem` flags
then concatMap getReference rest
else []
"readonly" -> concatMap getReference rest
"trap" ->
case rest of
head:_ -> map (\x -> (head, head, x)) $ getVariablesFromLiteralToken head
_ -> []
_ -> []
where
getReference t@(T_Assignment _ _ name _ value) = [(t, t, name)]
getReference t@(T_NormalWord _ [T_Literal _ name]) | not ("-" `isPrefixOf` name) = [(t, t, name)]
getReference _ = []
flags = map snd $ getAllFlags base
getReferencedVariableCommand _ = []
getModifiedVariableCommand base@(T_SimpleCommand _ _ (T_NormalWord _ (T_Literal _ x:_):rest)) =
filter (\(_,_,s,_) -> not ("-" `isPrefixOf` s)) $
case x of
"read" ->
let params = map getLiteral rest in
catMaybes . takeWhile isJust . reverse $ params
"getopts" ->
case rest of
opts:var:_ -> maybeToList $ getLiteral var
_ -> []
"let" -> concatMap letParamToLiteral rest
"export" ->
if "f" `elem` flags then [] else concatMap getModifierParamString rest
"declare" -> if any (`elem` flags) ["F", "f", "p"] then [] else declaredVars
"typeset" -> declaredVars
"local" -> concatMap getModifierParamString rest
"readonly" -> concatMap getModifierParamString rest
"set" -> maybeToList $ do
params <- getSetParams rest
return (base, base, "@", DataString $ SourceFrom params)
"printf" -> maybeToList $ getPrintfVariable rest
"mapfile" -> maybeToList $ getMapfileArray base rest
"readarray" -> maybeToList $ getMapfileArray base rest
_ -> []
where
flags = map snd $ getAllFlags base
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
declaredVars = concatMap (getModifierParam defaultType) rest
where
defaultType = if any (`elem` flags) ["a", "A"] then DataArray else DataString
getLiteral t = do
s <- getLiteralString t
when ("-" `isPrefixOf` s) $ fail "argument"
return (base, t, s, DataString SourceExternal)
getModifierParamString = getModifierParam DataString
getModifierParam def t@(T_Assignment _ _ name _ value) =
[(base, t, name, dataTypeFrom def value)]
getModifierParam def t@(T_NormalWord {}) = maybeToList $ do
name <- getLiteralString t
guard $ isVariableName name
return (base, t, name, def SourceDeclaration)
getModifierParam _ _ = []
letParamToLiteral token =
if var == ""
then []
else [(base, token, var, DataString $ SourceFrom [stripEqualsFrom token])]
where var = takeWhile isVariableChar $ dropWhile (`elem` "+-") $ concat $ deadSimple token
getSetParams (t:_:rest) | getLiteralString t == Just "-o" = getSetParams rest
getSetParams (t:rest) =
let s = getLiteralString t in
case s of
Just "--" -> return rest
Just ('-':_) -> getSetParams rest
_ -> return (t:fromMaybe [] (getSetParams rest))
getSetParams [] = Nothing
getPrintfVariable list = f $ map (\x -> (x, getLiteralString x)) list
where
f ((_, Just "-v") : (t, Just var) : _) = return (base, t, var, DataString $ SourceFrom list)
f (_:rest) = f rest
f [] = fail "not found"
-- mapfile has some curious syntax allowing flags plus 0..n variable names
-- where only the first non-option one is used if any. Here we cheat and
-- just get the last one, if it's a variable name.
getMapfileArray base arguments = do
lastArg <- listToMaybe (reverse arguments)
name <- getLiteralString lastArg
guard $ isVariableName name
return (base, lastArg, name, DataArray $ SourceExternal)
getModifiedVariableCommand _ = []
prop_getBracedReference1 = getBracedReference "foo" == "foo"
prop_getBracedReference2 = getBracedReference "#foo" == "foo"
prop_getBracedReference3 = getBracedReference "#" == "#"
prop_getBracedReference4 = getBracedReference "##" == "#"
prop_getBracedReference5 = getBracedReference "#!" == "!"
prop_getBracedReference6 = getBracedReference "!#" == "#"
prop_getBracedReference7 = getBracedReference "!foo#?" == "foo"
prop_getBracedReference8 = getBracedReference "foo-bar" == "foo"
prop_getBracedReference9 = getBracedReference "foo:-bar" == "foo"
prop_getBracedReference10= getBracedReference "foo: -1" == "foo"
getBracedReference s = fromMaybe s $
takeName noPrefix `mplus` getSpecial noPrefix `mplus` getSpecial s
where
noPrefix = dropPrefix s
dropPrefix (c:rest) = if c `elem` "!#" then rest else c:rest
dropPrefix "" = ""
takeName s = do
let name = takeWhile isVariableChar s
guard . not $ null name
return name
getSpecial (c:_) =
if c `elem` "*@#?-$!" then return [c] else fail "not special"
getSpecial _ = fail "empty"
getIndexReferences s = fromMaybe [] $ do
match <- matchRegex re s
index <- match !!! 0
return $ matchAllStrings variableNameRegex index
where
re = mkRegex "(\\[.*\\])"
getReferencedVariables t =
case t of
T_DollarBraced id l -> let str = bracedString l in
(t, t, getBracedReference str) :
map (\x -> (l, l, x)) (getIndexReferences str)
TA_Expansion id _ -> getIfReference t t
T_Assignment id mode str _ word ->
[(t, t, str) | mode == Append] ++ specialReferences str t word
TC_Unary id _ "-v" token -> getIfReference t token
TC_Unary id _ "-R" token -> getIfReference t token
x -> getReferencedVariableCommand x
where
-- Try to reduce false positives for unused vars only referenced from evaluated vars
specialReferences name base word =
if name `elem` [
"PS1", "PS2", "PS3", "PS4",
"PROMPT_COMMAND"
]
then
map (\x -> (base, base, x)) $
getVariablesFromLiteralToken word
else []
literalizer (TA_Index {}) = return "" -- x[0] becomes a reference of x
literalizer _ = Nothing
getIfReference context token = maybeToList $ do
str <- getLiteralStringExt literalizer token
guard . not $ null str
when (isDigit $ head str) $ fail "is a number"
return (context, token, getBracedReference str)
-- Try to get referenced variables from a literal string like "$foo"
-- Ignores tons of cases like arithmetic evaluation and array indices.
prop_getVariablesFromLiteral1 =
getVariablesFromLiteral "$foo${bar//a/b}$BAZ" == ["foo", "bar", "BAZ"]
getVariablesFromLiteral string =
map (!! 0) $ matchAllSubgroups variableRegex string
where
variableRegex = mkRegex "\\$\\{?([A-Za-z0-9_]+)"
getVariablesFromLiteralToken token =
getVariablesFromLiteral (fromJust $ getLiteralStringExt (const $ return " ") token)
getVariableFlow shell parents t =
let (_, stack) = runState (doStackAnalysis startScope endScope t) []
in reverse stack
where
startScope t =
let scopeType = leadType shell parents t
in do
when (scopeType /= NoneScope) $ modify (StackScope scopeType:)
when (assignFirst t) $ setWritten t
endScope t =
let scopeType = leadType shell parents t
in do
setRead t
unless (assignFirst t) $ 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
unless (shouldIgnore str) $ 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
where
shouldIgnore str =
str `elem` ["@", "*", "IFS"]
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 flow = evalState (
foldM (\list x -> do { l <- doFlow x; return $ l ++ list; }) [] flow
) empty
where
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_checkSpacefulness1 = verifyTree checkSpacefulness "a='cow moo'; echo $a"
prop_checkSpacefulness2 = verifyNotTree checkSpacefulness "a='cow moo'; [[ $a ]]"
prop_checkSpacefulness3 = verifyNotTree checkSpacefulness "a='cow*.mp3'; echo \"$a\""
prop_checkSpacefulness4 = verifyTree checkSpacefulness "for f in *.mp3; do echo $f; done"
prop_checkSpacefulness4a= verifyNotTree checkSpacefulness "foo=3; foo=$(echo $foo)"
prop_checkSpacefulness5 = verifyTree checkSpacefulness "a='*'; b=$a; c=lol${b//foo/bar}; echo $c"
prop_checkSpacefulness6 = verifyTree checkSpacefulness "a=foo$(lol); echo $a"
prop_checkSpacefulness7 = verifyTree checkSpacefulness "a=foo\\ bar; rm $a"
prop_checkSpacefulness8 = verifyNotTree checkSpacefulness "a=foo\\ bar; a=foo; rm $a"
prop_checkSpacefulness10= verifyTree checkSpacefulness "rm $1"
prop_checkSpacefulness11= verifyTree checkSpacefulness "rm ${10//foo/bar}"
prop_checkSpacefulness12= verifyNotTree checkSpacefulness "(( $1 + 3 ))"
prop_checkSpacefulness13= verifyNotTree checkSpacefulness "if [[ $2 -gt 14 ]]; then true; fi"
prop_checkSpacefulness14= verifyNotTree checkSpacefulness "foo=$3 env"
prop_checkSpacefulness15= verifyNotTree checkSpacefulness "local foo=$1"
prop_checkSpacefulness16= verifyNotTree checkSpacefulness "declare foo=$1"
prop_checkSpacefulness17= verifyTree checkSpacefulness "echo foo=$1"
prop_checkSpacefulness18= verifyNotTree checkSpacefulness "$1 --flags"
prop_checkSpacefulness19= verifyTree checkSpacefulness "echo $PWD"
prop_checkSpacefulness20= verifyNotTree checkSpacefulness "n+='foo bar'"
prop_checkSpacefulness21= verifyNotTree checkSpacefulness "select foo in $bar; do true; done"
prop_checkSpacefulness22= verifyNotTree checkSpacefulness "echo $\"$1\""
prop_checkSpacefulness23= verifyNotTree checkSpacefulness "a=(1); echo ${a[@]}"
prop_checkSpacefulness24= verifyTree checkSpacefulness "a='a b'; cat <<< $a"
prop_checkSpacefulness25= verifyTree checkSpacefulness "a='s/[0-9]//g'; sed $a"
prop_checkSpacefulness26= verifyTree checkSpacefulness "a='foo bar'; echo {1,2,$a}"
checkSpacefulness params t =
doVariableFlowAnalysis readF writeF (Map.fromList defaults) (variableFlow params)
where
defaults = zip variablesWithoutSpaces (repeat False)
hasSpaces name = do
map <- get
return $ Map.findWithDefault True name map
setSpaces name bool =
modify $ Map.insert name bool
readF _ token name = do
spaced <- hasSpaces name
return [Note (getId token) InfoC 2086 warning |
spaced
&& not (isArrayExpansion token) -- There's another warning for this
&& not (isCounting token)
&& not (isQuoteFree parents token)
&& not (usedAsCommandName parents token)]
where
warning = "Double quote to prevent globbing and word splitting."
writeF _ _ name (DataString SourceExternal) = do
setSpaces name True
return []
writeF _ _ name (DataString (SourceFrom vals)) = do
map <- get
setSpaces name
(isSpacefulWord (\x -> Map.findWithDefault True x map) vals)
return []
writeF _ _ _ _ = return []
parents = parentMap params
isCounting (T_DollarBraced id token) =
case concat $ deadSimple token of
'#':_ -> True
_ -> False
isCounting _ = False
isSpacefulWord :: (String -> Bool) -> [Token] -> Bool
isSpacefulWord f = any (isSpaceful f)
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 = any (`elem` s)
prop_checkQuotesInLiterals1 = verifyTree checkQuotesInLiterals "param='--foo=\"bar\"'; app $param"
prop_checkQuotesInLiterals1a= verifyTree checkQuotesInLiterals "param=\"--foo='lolbar'\"; app $param"
prop_checkQuotesInLiterals2 = verifyNotTree checkQuotesInLiterals "param='--foo=\"bar\"'; app \"$param\""
prop_checkQuotesInLiterals3 =verifyNotTree checkQuotesInLiterals "param=('--foo='); app \"${param[@]}\""
prop_checkQuotesInLiterals4 = verifyNotTree checkQuotesInLiterals "param=\"don't bother with this one\"; app $param"
prop_checkQuotesInLiterals5 = verifyNotTree checkQuotesInLiterals "param=\"--foo='lolbar'\"; eval app $param"
prop_checkQuotesInLiterals6 = verifyTree checkQuotesInLiterals "param='my\\ file'; cmd=\"rm $param\"; $cmd"
prop_checkQuotesInLiterals6a= verifyNotTree checkQuotesInLiterals "param='my\\ file'; cmd=\"rm ${#param}\"; $cmd"
prop_checkQuotesInLiterals7 = verifyTree checkQuotesInLiterals "param='my\\ file'; rm $param"
prop_checkQuotesInLiterals8 = verifyTree checkQuotesInLiterals "param=\"/foo/'bar baz'/etc\"; rm $param"
checkQuotesInLiterals params t =
doVariableFlowAnalysis readF writeF Map.empty (variableFlow params)
where
getQuotes name = liftM (Map.lookup name) get
setQuotes name ref = modify $ Map.insert name ref
deleteQuotes = modify . Map.delete
parents = parentMap params
quoteRegex = mkRegex "\"|([/= ]|^)'|'( |$)|\\\\ "
containsQuotes s = s `matches` quoteRegex
writeF _ _ name (DataString (SourceFrom values)) = do
quoteMap <- get
let quotedVars = msum $ map (forToken quoteMap) values
case quotedVars of
Nothing -> deleteQuotes name
Just x -> setQuotes name x
return []
writeF _ _ _ _ = return []
forToken map (T_DollarBraced id t) =
-- skip getBracedReference here to avoid false positives on PE
Map.lookup (concat . deadSimple $ t) map
forToken quoteMap (T_DoubleQuoted id tokens) =
msum $ map (forToken quoteMap) tokens
forToken quoteMap (T_NormalWord id tokens) =
msum $ map (forToken quoteMap) tokens
forToken _ t =
if containsQuotes (concat $ deadSimple t)
then return $ getId t
else Nothing
readF _ expr name = do
assignment <- getQuotes name
return
(if isJust assignment
&& not (isParamTo parents "eval" expr)
&& not (isQuoteFree parents expr)
then [
Note (fromJust assignment)WarningC 2089
"Quotes/backslashes will be treated literally. Use an array.",
Note (getId expr) WarningC 2090
"Quotes/backslashes in this variable will not be respected."
]
else [])
prop_checkFunctionsUsedExternally1 =
verifyTree checkFunctionsUsedExternally "foo() { :; }; sudo foo"
prop_checkFunctionsUsedExternally2 =
verifyTree checkFunctionsUsedExternally "alias f='a'; xargs -n 1 f"
prop_checkFunctionsUsedExternally3 =
verifyNotTree checkFunctionsUsedExternally "f() { :; }; echo f"
prop_checkFunctionsUsedExternally4 =
verifyNotTree checkFunctionsUsedExternally "foo() { :; }; sudo \"foo\""
checkFunctionsUsedExternally params t =
runNodeAnalysis checkCommand params 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 ()
analyse f t = execState (doAnalysis f t) []
functions = Map.fromList $ analyse 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 = potentially $ do
literalArg <- getUnquotedLiteral arg -- only consider unquoted literals
definitionId <- Map.lookup literalArg functions
return $ do
warn (getId arg) 2033
"Shell functions can't be passed to external commands."
info definitionId 2032 $
"Use own script or sh -c '..' to run this from " ++ cmd ++ "."
prop_checkUnused0 = verifyNotTree checkUnusedAssignments "var=foo; echo $var"
prop_checkUnused1 = verifyTree checkUnusedAssignments "var=foo; echo $bar"
prop_checkUnused2 = verifyNotTree checkUnusedAssignments "var=foo; export var;"
prop_checkUnused3 = verifyTree checkUnusedAssignments "for f in *; do echo '$f'; done"
prop_checkUnused4 = verifyTree checkUnusedAssignments "local i=0"
prop_checkUnused5 = verifyNotTree checkUnusedAssignments "read lol; echo $lol"
prop_checkUnused6 = verifyNotTree checkUnusedAssignments "var=4; (( var++ ))"
prop_checkUnused7 = verifyNotTree checkUnusedAssignments "var=2; $((var))"
prop_checkUnused8 = verifyTree checkUnusedAssignments "var=2; var=3;"
prop_checkUnused9 = verifyNotTree checkUnusedAssignments "read ''"
prop_checkUnused10= verifyNotTree checkUnusedAssignments "read -p 'test: '"
prop_checkUnused11= verifyNotTree checkUnusedAssignments "bar=5; export foo[$bar]=3"
prop_checkUnused12= verifyNotTree checkUnusedAssignments "read foo; echo ${!foo}"
prop_checkUnused13= verifyNotTree checkUnusedAssignments "x=(1); (( x[0] ))"
prop_checkUnused14= verifyNotTree checkUnusedAssignments "x=(1); n=0; echo ${x[n]}"
prop_checkUnused15= verifyNotTree checkUnusedAssignments "x=(1); n=0; (( x[n] ))"
prop_checkUnused16= verifyNotTree checkUnusedAssignments "foo=5; declare -x foo"
prop_checkUnused17= verifyNotTree checkUnusedAssignments "read -i 'foo' -e -p 'Input: ' bar; $bar;"
prop_checkUnused18= verifyNotTree checkUnusedAssignments "a=1; arr=( [$a]=42 ); echo \"${arr[@]}\""
prop_checkUnused19= verifyNotTree checkUnusedAssignments "a=1; let b=a+1; echo $b"
prop_checkUnused20= verifyNotTree checkUnusedAssignments "a=1; PS1='$a'"
prop_checkUnused21= verifyNotTree checkUnusedAssignments "a=1; trap 'echo $a' INT"
prop_checkUnused22= verifyNotTree checkUnusedAssignments "a=1; [ -v a ]"
prop_checkUnused23= verifyNotTree checkUnusedAssignments "a=1; [ -R a ]"
prop_checkUnused24= verifyNotTree checkUnusedAssignments "mapfile -C a b; echo ${b[@]}"
prop_checkUnused25= verifyNotTree checkUnusedAssignments "readarray foo; echo ${foo[@]}"
prop_checkUnused26= verifyNotTree checkUnusedAssignments "declare -F foo"
checkUnusedAssignments params t = execWriter (mapM_ warnFor unused)
where
flow = variableFlow params
references = foldl (flip ($)) defaultMap (map insertRef flow)
insertRef (Reference (base, token, name)) =
Map.insert (stripSuffix name) ()
insertRef _ = id
assignments = foldl (flip ($)) Map.empty (map insertAssignment flow)
insertAssignment (Assignment (_, token, name, _)) | isVariableName name =
Map.insert name token
insertAssignment _ = id
unused = Map.assocs $ Map.difference assignments references
warnFor (name, token) =
warn (getId token) 2034 $
name ++ " appears unused. Verify it or export it."
stripSuffix = takeWhile isVariableChar
defaultMap = Map.fromList $ zip internalVariables $ repeat ()
prop_checkUnassignedReferences1 = verifyTree checkUnassignedReferences "echo $foo"
prop_checkUnassignedReferences2 = verifyNotTree checkUnassignedReferences "foo=hello; echo $foo"
prop_checkUnassignedReferences3 = verifyTree checkUnassignedReferences "MY_VALUE=3; echo $MYVALUE"
prop_checkUnassignedReferences4 = verifyNotTree checkUnassignedReferences "RANDOM2=foo; echo $RANDOM"
prop_checkUnassignedReferences5 = verifyNotTree checkUnassignedReferences "declare -A foo=([bar]=baz); echo ${foo[bar]}"
prop_checkUnassignedReferences6 = verifyNotTree checkUnassignedReferences "foo=..; echo ${foo-bar}"
prop_checkUnassignedReferences7 = verifyNotTree checkUnassignedReferences "getopts ':h' foo; echo $foo"
prop_checkUnassignedReferences8 = verifyNotTree checkUnassignedReferences "let 'foo = 1'; echo $foo"
prop_checkUnassignedReferences9 = verifyNotTree checkUnassignedReferences "echo ${foo-bar}"
prop_checkUnassignedReferences10= verifyNotTree checkUnassignedReferences "echo ${foo:?}"
prop_checkUnassignedReferences11= verifyNotTree checkUnassignedReferences "declare -A foo; echo \"${foo[@]}\""
prop_checkUnassignedReferences12= verifyNotTree checkUnassignedReferences "typeset -a foo; echo \"${foo[@]}\""
prop_checkUnassignedReferences13= verifyNotTree checkUnassignedReferences "f() { local foo; echo $foo; }"
prop_checkUnassignedReferences14= verifyNotTree checkUnassignedReferences "foo=; echo $foo"
prop_checkUnassignedReferences15= verifyNotTree checkUnassignedReferences "f() { true; }; export -f f"
prop_checkUnassignedReferences16= verifyNotTree checkUnassignedReferences "declare -A foo=( [a b]=bar ); echo ${foo[a b]}"
prop_checkUnassignedReferences17= verifyNotTree checkUnassignedReferences "USERS=foo; echo $USER"
prop_checkUnassignedReferences18= verifyNotTree checkUnassignedReferences "FOOBAR=42; export FOOBAR="
prop_checkUnassignedReferences19= verifyNotTree checkUnassignedReferences "readonly foo=bar; echo $foo"
prop_checkUnassignedReferences20= verifyNotTree checkUnassignedReferences "printf -v foo bar; echo $foo"
prop_checkUnassignedReferences21= verifyTree checkUnassignedReferences "echo ${#foo}"
checkUnassignedReferences params t = warnings
where
(readMap, writeMap) = execState (mapM tally $ variableFlow params) (Map.empty, Map.empty)
defaultAssigned = Map.fromList $ map (\a -> (a, ())) $ filter (not . null) internalVariables
tally (Assignment (_, _, name, _)) =
modify (\(read, written) -> (read, Map.insert name () written))
tally (Reference (_, place, name)) =
modify (\(read, written) -> (Map.insertWith' (const id) name place read, written))
tally _ = return ()
unassigned = Map.toList $ Map.difference (Map.difference readMap writeMap) defaultAssigned
writtenVars = filter isVariableName $ Map.keys writeMap
getBestMatch var = do
(match, score) <- listToMaybe best
guard $ goodMatch var match score
return match
where
matches = map (\x -> (x, match var x)) writtenVars
best = sortBy (comparing snd) matches
goodMatch var match score =
let l = length match in
l > 3 && score <= 1
|| l > 7 && score <= 2
isLocal = any isLower
warningForGlobals var place = do
match <- getBestMatch var
return $ warn (getId place) 2153 $
"Possible misspelling: " ++ var ++ " may not be assigned, but " ++ match ++ " is."
warningForLocals var place =
return $ warn (getId place) 2154 $
var ++ " is referenced but not assigned" ++ optionalTip ++ "."
where
optionalTip =
if var `elem` commonCommands
then " (for output from commands, use \"$(" ++ var ++ " ..." ++ ")\" )"
else fromMaybe "" $ do
match <- getBestMatch var
return $ " (did you mean '" ++ match ++ "'?)"
warningFor var place = do
guard . not $ isInArray var place || isGuarded place
(if isLocal var then warningForLocals else warningForGlobals) var place
warnings = execWriter . sequence $ mapMaybe (uncurry warningFor) unassigned
-- Due to parsing, foo=( [bar]=baz ) parses 'bar' as a reference even for assoc arrays.
-- Similarly, ${foo[bar baz]} may not be referencing bar/baz. Just skip these.
isInArray var t = any isArray $ getPath (parentMap params) t
where
isArray (T_Array {}) = True
isArray (T_DollarBraced _ l) | var /= getBracedReference (bracedString l) = True
isArray _ = False
isGuarded (T_DollarBraced _ v) =
any (`isPrefixOf` rest) ["-", ":-", "?", ":?"]
where
name = concat $ deadSimple v
rest = dropWhile isVariableChar $ dropWhile (`elem` "#!") $ name
isGuarded _ = False
match var candidate =
if var /= candidate && (map toLower var) == (map toLower candidate)
then 1
else dist var candidate
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"
prop_checkWhileReadPitfalls7 = verify checkWhileReadPitfalls "while read foo; do if true; then ssh $foo uptime; fi; done < file"
checkWhileReadPitfalls _ (T_WhileExpression id [command] contents)
| isStdinReadCommand command =
mapM_ checkMuncher contents
where
munchers = [ "ssh", "ffmpeg", "mplayer" ]
isStdinReadCommand (T_Pipeline _ _ [T_Redirecting id redirs cmd]) =
let plaintext = deadSimple cmd
in head (plaintext ++ [""]) == "read"
&& ("-u" `notElem` plaintext)
&& all (not . stdinRedirect) redirs
isStdinReadCommand _ = False
checkMuncher (T_Pipeline _ _ (T_Redirecting _ redirs cmd:_)) | not $ any stdinRedirect redirs =
case cmd of
(T_IfExpression _ thens elses) ->
mapM_ checkMuncher . concat $ map fst thens ++ map snd thens ++ [elses]
_ -> potentially $ do
name <- getCommandBasename cmd
guard $ name `elem` munchers
return $ 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 = verify checkPrefixAssignmentReference "var=foo echo $var"
prop_checkPrefixAssign2 = verifyNot checkPrefixAssignmentReference "var=$(echo $var) cmd"
checkPrefixAssignmentReference params t@(T_DollarBraced id value) =
check path
where
name = getBracedReference $ bracedString value
path = getPath (parentMap params) 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 && (aId `notElem` 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]"
prop_checkCharRangeGlob5 = verifyNot checkCharRangeGlob "tr -d [a-zA-Z]" -- tr has 2060
checkCharRangeGlob p t@(T_Glob id str) |
isCharClass str && not (isParamTo (parentMap p) "tr" t) =
if ":" `isPrefixOf` contents
&& ":" `isSuffixOf` contents
&& contents /= ":"
then warn id 2101 "Named class needs outer [], e.g. [[:digit:]]."
else
when ('[' `notElem` contents && hasDupes) $
info id 2102 "Ranges can only match single chars (mentioned due to duplicates)."
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 "for f in *; do cd $f; git pull; cd ..; done"
prop_checkCdAndBack2 = verifyNot checkCdAndBack "for f in *; do cd $f || continue; git pull; cd ..; done"
prop_checkCdAndBack3 = verifyNot checkCdAndBack "while [[ $PWD != / ]]; do cd ..; done"
checkCdAndBack params = doLists
where
shell = shellType params
doLists (T_ForIn _ _ _ cmds) = doList cmds
doLists (T_ForArithmetic _ _ _ _ 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
then "Consider using ( subshell ), 'cd foo||exit', or pushd/popd instead."
else "Consider using ( subshell ) or 'cd foo||exit' instead."
prop_checkLoopKeywordScope1 = verify checkLoopKeywordScope "continue 2"
prop_checkLoopKeywordScope2 = verify checkLoopKeywordScope "for f; do ( break; ); done"
prop_checkLoopKeywordScope3 = verify checkLoopKeywordScope "if true; then continue; fi"
prop_checkLoopKeywordScope4 = verifyNot checkLoopKeywordScope "while true; do break; done"
prop_checkLoopKeywordScope5 = verify checkLoopKeywordScope "if true; then break; fi"
prop_checkLoopKeywordScope6 = verify checkLoopKeywordScope "while true; do true | { break; }; done"
prop_checkLoopKeywordScope7 = verifyNot checkLoopKeywordScope "#!/bin/ksh\nwhile true; do true | { break; }; done"
checkLoopKeywordScope params t |
name `elem` map Just ["continue", "break"] =
if not $ any isLoop path
then if any isFunction $ take 1 path
-- breaking at a source/function invocation is an abomination. Let's ignore it.
then err (getId t) 2104 $ "In functions, use return instead of " ++ fromJust name ++ "."
else err (getId t) 2105 $ fromJust name ++ " is only valid in loops."
else case map subshellType $ filter (not . isFunction) path of
Just str:_ -> warn (getId t) 2106 $
"This only exits the subshell caused by the " ++ str ++ "."
_ -> return ()
where
name = getCommandName t
path = let p = getPath (parentMap params) t in filter relevant p
subshellType t = case leadType (shellType params) (parentMap params) t of
NoneScope -> Nothing
SubshellScope str -> return str
isFunction t = case t of T_Function {} -> True; _ -> False
relevant t = isLoop t || isFunction t || isJust (subshellType t)
checkLoopKeywordScope _ _ = return ()
prop_checkFunctionDeclarations1 = verify checkFunctionDeclarations "#!/bin/ksh\nfunction foo() { command foo --lol \"$@\"; }"
prop_checkFunctionDeclarations2 = verify checkFunctionDeclarations "#!/bin/dash\nfunction foo { lol; }"
prop_checkFunctionDeclarations3 = verifyNot checkFunctionDeclarations "foo() { echo bar; }"
checkFunctionDeclarations params
(T_Function id (FunctionKeyword hasKeyword) (FunctionParentheses hasParens) _ _) =
case shellType params of
Bash -> return ()
Ksh ->
when (hasKeyword && hasParens) $
err id 2111 "ksh does not allow 'function' keyword and '()' at the same time."
Sh -> do
when (hasKeyword && hasParens) $
warn id 2112 "'function' keyword is non-standard. Delete it."
when (hasKeyword && not hasParens) $
warn id 2113 "'function' keyword is non-standard. Use 'foo()' instead of 'function foo'."
checkFunctionDeclarations _ _ = return ()
prop_checkCatastrophicRm1 = verify checkCatastrophicRm "rm -r $1/$2"
prop_checkCatastrophicRm2 = verify checkCatastrophicRm "rm -r /home/$foo"
prop_checkCatastrophicRm3 = verifyNot checkCatastrophicRm "rm -r /home/${USER:?}/*"
prop_checkCatastrophicRm4 = verify checkCatastrophicRm "rm -fr /home/$(whoami)/*"
prop_checkCatastrophicRm5 = verifyNot checkCatastrophicRm "rm -r /home/${USER:-thing}/*"
prop_checkCatastrophicRm6 = verify checkCatastrophicRm "rm --recursive /etc/*$config*"
prop_checkCatastrophicRm8 = verify checkCatastrophicRm "rm -rf /home"
prop_checkCatastrophicRm9 = verifyNot checkCatastrophicRm "rm -rf -- /home"
prop_checkCatastrophicRm10= verifyNot checkCatastrophicRm "rm -r \"${DIR}\"/{.gitignore,.gitattributes,ci}"
prop_checkCatastrophicRm11= verify checkCatastrophicRm "rm -r /{bin,sbin}/$exec"
prop_checkCatastrophicRm12= verify checkCatastrophicRm "rm -r /{{usr,},{bin,sbin}}/$exec"
prop_checkCatastrophicRm13= verifyNot checkCatastrophicRm "rm -r /{{a,b},{c,d}}/$exec"
prop_checkCatastrophicRmA = verify checkCatastrophicRm "rm -rf /usr /lib/nvidia-current/xorg/xorg"
prop_checkCatastrophicRmB = verify checkCatastrophicRm "rm -rf \"$STEAMROOT/\"*"
checkCatastrophicRm params t@(T_SimpleCommand id _ tokens) | t `isCommand` "rm" =
when (any isRecursiveFlag simpleArgs) $
mapM_ (mapM_ checkWord . braceExpand) tokens
where
simpleArgs = deadSimple t
checkWord token =
case getLiteralString token of
Just str ->
when (notElem "--" simpleArgs && (fixPath str `elem` importantPaths)) $
warn (getId token) 2114 "Warning: deletes a system directory. Use 'rm --' to disable this message."
Nothing ->
checkWord' token
checkWord' token = fromMaybe (return ()) $ do
filename <- getPotentialPath token
let path = fixPath filename
return . when (path `elem` importantPaths) $
warn (getId token) 2115 $ "Use \"${var:?}\" to ensure this never expands to " ++ path ++ " ."
fixPath filename =
let normalized = skipRepeating '/' . skipRepeating '*' $ filename in
if normalized == "/" then normalized else stripTrailing '/' normalized
getPotentialPath = getLiteralStringExt f
where
f (T_Glob _ str) = return str
f (T_DollarBraced _ word) =
let var = onlyLiteralString word in
if any (flip isInfixOf var) [":?", ":-", ":="]
then Nothing
else return ""
f _ = return ""
isRecursiveFlag "--recursive" = True
isRecursiveFlag ('-':'-':_) = False
isRecursiveFlag ('-':str) = 'r' `elem` str || 'R' `elem` str
isRecursiveFlag _ = False
stripTrailing c = reverse . dropWhile (== c) . reverse
skipRepeating c (a:b:rest) | a == b && b == c = skipRepeating c (b:rest)
skipRepeating c (a:r) = a:skipRepeating c r
skipRepeating _ [] = []
paths = [
"", "/bin", "/etc", "/home", "/mnt", "/usr", "/usr/share", "/usr/local",
"/var", "/lib"
]
importantPaths = filter (not . null) $
["", "/", "/*", "/*/*"] >>= (\x -> map (++x) paths)
checkCatastrophicRm _ _ = return ()
prop_checkInteractiveSu1 = verify checkInteractiveSu "su; rm file; su $USER"
prop_checkInteractiveSu2 = verify checkInteractiveSu "su foo; something; exit"
prop_checkInteractiveSu3 = verifyNot checkInteractiveSu "echo rm | su foo"
prop_checkInteractiveSu4 = verifyNot checkInteractiveSu "su root < script"
checkInteractiveSu params = checkCommand "su" f
where
f cmd l = when (length l <= 1) $
when (all undirected $ getPath (parentMap params) cmd) $
info (getId cmd) 2117
"To run commands as another user, use su -c or sudo."
undirected (T_Pipeline _ _ l) = length l <= 1
-- This should really just be modifications to stdin, but meh
undirected (T_Redirecting _ list _) = null list
undirected _ = True
prop_checkStderrPipe1 = verify checkStderrPipe "#!/bin/ksh\nfoo |& bar"
prop_checkStderrPipe2 = verifyNot checkStderrPipe "#!/bin/bash\nfoo |& bar"
checkStderrPipe params =
case shellType params of
Ksh -> match
_ -> const $ return ()
where
match (T_Pipe id "|&") =
err id 2118 "Ksh does not support |&. Use 2>&1 |."
match _ = return ()
prop_checkUnpassedInFunctions1 = verifyTree checkUnpassedInFunctions "foo() { echo $1; }; foo"
prop_checkUnpassedInFunctions2 = verifyNotTree checkUnpassedInFunctions "foo() { echo $1; };"
prop_checkUnpassedInFunctions3 = verifyNotTree checkUnpassedInFunctions "foo() { echo $lol; }; foo"
prop_checkUnpassedInFunctions4 = verifyNotTree checkUnpassedInFunctions "foo() { echo $0; }; foo"
prop_checkUnpassedInFunctions5 = verifyNotTree checkUnpassedInFunctions "foo() { echo $1; }; foo 'lol'; foo"
prop_checkUnpassedInFunctions6 = verifyNotTree checkUnpassedInFunctions "foo() { set -- *; echo $1; }; foo"
prop_checkUnpassedInFunctions7 = verifyTree checkUnpassedInFunctions "foo() { echo $1; }; foo; foo;"
prop_checkUnpassedInFunctions8 = verifyNotTree checkUnpassedInFunctions "foo() { echo $((1)); }; foo;"
prop_checkUnpassedInFunctions9 = verifyNotTree checkUnpassedInFunctions "foo() { echo $(($b)); }; foo;"
prop_checkUnpassedInFunctions10= verifyNotTree checkUnpassedInFunctions "foo() { echo $!; }; foo;"
prop_checkUnpassedInFunctions11= verifyNotTree checkUnpassedInFunctions "foo() { bar() { echo $1; }; bar baz; }; foo;"
checkUnpassedInFunctions params root =
execWriter $ mapM_ warnForGroup referenceGroups
where
functionMap :: Map.Map String Token
functionMap = Map.fromList $
map (\t@(T_Function _ _ _ name _) -> (name,t)) functions
functions = execWriter $ doAnalysis (tell . maybeToList . findFunction) root
findFunction t@(T_Function id _ _ name body) =
let flow = getVariableFlow (shellType params) (parentMap params) body
in
if any (isPositionalReference t) flow && not (any isPositionalAssignment flow)
then return t
else Nothing
findFunction _ = Nothing
isPositionalAssignment x =
case x of
Assignment (_, _, str, _) -> isPositional str
_ -> False
isPositionalReference function x =
case x of
Reference (_, t, str) -> isPositional str && t `isDirectChildOf` function
_ -> False
isDirectChildOf child parent = fromMaybe False $ do
function <- find (\x -> case x of T_Function {} -> True; _ -> False) $ getPath (parentMap params) child
return $ getId parent == getId function
referenceList :: [(String, Bool, Token)]
referenceList = execWriter $
doAnalysis (fromMaybe (return ()) . checkCommand) root
checkCommand :: Token -> Maybe (Writer [(String, Bool, Token)] ())
checkCommand t@(T_SimpleCommand _ _ (cmd:args)) = do
str <- getLiteralString cmd
unless (Map.member str functionMap) $ fail "irrelevant"
return $ tell [(str, null args, t)]
checkCommand _ = Nothing
isPositional str = str == "*" || str == "@"
|| (all isDigit str && str /= "0")
isArgumentless (_, b, _) = b
referenceGroups = Map.elems $ foldr updateWith Map.empty referenceList
updateWith x@(name, _, _) = Map.insertWith (++) name [x]
warnForGroup group =
when (all isArgumentless group) $ do
mapM_ suggestParams group
warnForDeclaration group
suggestParams (name, _, thing) =
info (getId thing) 2119 $
"Use " ++ name ++ " \"$@\" if function's $1 should mean script's $1."
warnForDeclaration ((name, _, _):_) =
warn (getId . fromJust $ Map.lookup name functionMap) 2120 $
name ++ " references arguments, but none are ever passed."
prop_checkSetAssignment1 = verify checkSetAssignment "set foo 42"
prop_checkSetAssignment2 = verify checkSetAssignment "set foo = 42"
prop_checkSetAssignment3 = verify checkSetAssignment "set foo=42"
prop_checkSetAssignment4 = verifyNot checkSetAssignment "set -- if=/dev/null"
prop_checkSetAssignment5 = verifyNot checkSetAssignment "set 'a=5'"
prop_checkSetAssignment6 = verifyNot checkSetAssignment "set"
checkSetAssignment params = checkUnqualifiedCommand "set" f
where
f cmd (var:value:rest) =
let str = literal var in
when (isVariableName str || isAssignment str) $
msg (getId var)
f cmd (var:_) =
when (isAssignment $ literal var) $
msg (getId var)
f _ _ = return ()
msg id = warn id 2121 "To assign a variable, use just 'var=value', no 'set ..'."
isAssignment str = '=' `elem` str
literal (T_NormalWord _ l) = concatMap literal l
literal (T_Literal _ str) = str
literal _ = "*"
prop_checkOverridingPath1 = verify checkOverridingPath "PATH=\"$var/$foo\""
prop_checkOverridingPath2 = verify checkOverridingPath "PATH=\"mydir\""
prop_checkOverridingPath3 = verify checkOverridingPath "PATH=/cow/foo"
prop_checkOverridingPath4 = verifyNot checkOverridingPath "PATH=/cow/foo/bin"
prop_checkOverridingPath5 = verifyNot checkOverridingPath "PATH='/bin:/sbin'"
prop_checkOverridingPath6 = verifyNot checkOverridingPath "PATH=\"$var/$foo\" cmd"
prop_checkOverridingPath7 = verifyNot checkOverridingPath "PATH=$OLDPATH"
prop_checkOverridingPath8 = verifyNot checkOverridingPath "PATH=$PATH:/stuff"
checkOverridingPath _ (T_SimpleCommand _ vars []) =
mapM_ checkVar vars
where
checkVar (T_Assignment id Assign "PATH" Nothing word) =
let string = concat $ deadSimple word
in unless (any (`isInfixOf` string) ["/bin", "/sbin" ]) $ do
when ('/' `elem` string && ':' `notElem` string) $ notify id
when (isLiteral word && ':' `notElem` string && '/' `notElem` string) $ notify id
checkVar _ = return ()
notify id = warn id 2123 "PATH is the shell search path. Use another name."
checkOverridingPath _ _ = return ()
prop_checkTildeInPath1 = verify checkTildeInPath "PATH=\"$PATH:~/bin\""
prop_checkTildeInPath2 = verify checkTildeInPath "PATH='~foo/bin'"
prop_checkTildeInPath3 = verifyNot checkTildeInPath "PATH=~/bin"
checkTildeInPath _ (T_SimpleCommand _ vars _) =
mapM_ checkVar vars
where
checkVar (T_Assignment id Assign "PATH" Nothing (T_NormalWord _ parts)) =
when (any (\x -> isQuoted x && hasTilde x) parts) $
warn id 2147 "Literal tilde in PATH works poorly across programs."
checkVar _ = return ()
hasTilde t = fromMaybe False (liftM2 elem (return '~') (getLiteralStringExt (const $ return "") t))
isQuoted (T_DoubleQuoted {}) = True
isQuoted (T_SingleQuoted {}) = True
isQuoted _ = False
checkTildeInPath _ _ = return ()
prop_checkUnsupported3 = verify checkUnsupported "#!/bin/sh\ncase foo in bar) baz ;& esac"
prop_checkUnsupported4 = verify checkUnsupported "#!/bin/ksh\ncase foo in bar) baz ;;& esac"
checkUnsupported params t =
when (not (null support) && (shellType params `notElem` support)) $
report name
where
(name, support) = shellSupport t
report s = err (getId t) 2127 $
"To use " ++ s ++ ", specify #!/usr/bin/env " ++
(map toLower . intercalate " or " . map show $ support)
-- TODO: Move more of these checks here
shellSupport t =
case t of
T_CaseExpression _ _ list -> forCase (map (\(a,_,_) -> a) list)
otherwise -> ("", [])
where
forCase seps | CaseContinue `elem` seps = ("cases with ;;&", [Bash])
forCase seps | CaseFallThrough `elem` seps = ("cases with ;&", [Bash, Ksh])
forCase _ = ("", [])
getCommandSequences (T_Script _ _ cmds) = [cmds]
getCommandSequences (T_BraceGroup _ cmds) = [cmds]
getCommandSequences (T_Subshell _ cmds) = [cmds]
getCommandSequences (T_WhileExpression _ _ cmds) = [cmds]
getCommandSequences (T_UntilExpression _ _ cmds) = [cmds]
getCommandSequences (T_ForIn _ _ _ cmds) = [cmds]
getCommandSequences (T_ForArithmetic _ _ _ _ cmds) = [cmds]
getCommandSequences (T_IfExpression _ thens elses) = map snd thens ++ [elses]
getCommandSequences _ = []
groupWith f = groupBy ((==) `on` f)
prop_checkMultipleAppends1 = verify checkMultipleAppends "foo >> file; bar >> file; baz >> file;"
prop_checkMultipleAppends2 = verify checkMultipleAppends "foo >> file; bar | grep f >> file; baz >> file;"
prop_checkMultipleAppends3 = verifyNot checkMultipleAppends "foo < file; bar < file; baz < file;"
checkMultipleAppends params t =
mapM_ checkList $ getCommandSequences t
where
checkList list =
mapM_ checkGroup (groupWith (liftM fst) $ map getTarget list)
checkGroup (f:_:_:_) | isJust f =
style (snd $ fromJust f) 2129
"Consider using { cmd1; cmd2; } >> file instead of individual redirects."
checkGroup _ = return ()
getTarget (T_Pipeline _ _ args@(_:_)) = getTarget (last args)
getTarget (T_Redirecting id list _) = do
file <- mapMaybe getAppend list !!! 0
return (file, id)
getTarget _ = Nothing
getAppend (T_FdRedirect _ _ (T_IoFile _ (T_DGREAT {}) f)) = return f
getAppend _ = Nothing
prop_checkAliasesExpandEarly1 = verify checkAliasesExpandEarly "alias foo=\"echo $PWD\""
prop_checkAliasesExpandEarly2 = verifyNot checkAliasesExpandEarly "alias -p"
prop_checkAliasesExpandEarly3 = verifyNot checkAliasesExpandEarly "alias foo='echo {1..10}'"
checkAliasesExpandEarly params =
checkUnqualifiedCommand "alias" (const f)
where
f = mapM_ checkArg
checkArg arg | '=' `elem` concat (deadSimple arg) =
forM_ (take 1 $ filter (not . isLiteral) $ getWordParts arg) $
\x -> warn (getId x) 2139 "This expands when defined, not when used. Consider escaping."
checkArg _ = return ()
prop_checkSuspiciousIFS1 = verify checkSuspiciousIFS "IFS=\"\\n\""
prop_checkSuspiciousIFS2 = verifyNot checkSuspiciousIFS "IFS=$'\\t'"
checkSuspiciousIFS params (T_Assignment id Assign "IFS" Nothing value) =
potentially $ do
str <- getLiteralString value
return $ check str
where
n = if shellType params == Sh then "''" else "$'\\n'"
t = if shellType params == Sh then "\"$(printf '\\t')\"" else "$'\\t'"
check value =
case value of
"\\n" -> suggest n
"/n" -> suggest n
"\\t" -> suggest t
"/t" -> suggest t
_ -> return ()
suggest r = warn id 2141 $ "Did you mean IFS=" ++ r ++ " ?"
checkSuspiciousIFS _ _ = return ()
prop_checkAliasesUsesArgs1 = verify checkAliasesUsesArgs "alias a='cp $1 /a'"
prop_checkAliasesUsesArgs2 = verifyNot checkAliasesUsesArgs "alias $1='foo'"
prop_checkAliasesUsesArgs3 = verify checkAliasesUsesArgs "alias a=\"echo \\${@}\""
checkAliasesUsesArgs params =
checkUnqualifiedCommand "alias" (const f)
where
re = mkRegex "\\$\\{?[0-9*@]"
f = mapM_ checkArg
checkArg arg =
let string = fromJust $ getLiteralStringExt (const $ return "_") arg in
when ('=' `elem` string && string `matches` re) $
err (getId arg) 2142
"Aliases can't use positional parameters. Use a function."
prop_checkGrepQ1= verify checkShouldUseGrepQ "[[ $(foo | grep bar) ]]"
prop_checkGrepQ2= verify checkShouldUseGrepQ "[ -z $(fgrep lol) ]"
prop_checkGrepQ3= verify checkShouldUseGrepQ "[ -n \"$(foo | zgrep lol)\" ]"
prop_checkGrepQ4= verifyNot checkShouldUseGrepQ "[ -z $(grep bar | cmd) ]"
prop_checkGrepQ5= verifyNot checkShouldUseGrepQ "rm $(ls | grep file)"
prop_checkGrepQ6= verifyNot checkShouldUseGrepQ "[[ -n $(pgrep foo) ]]"
checkShouldUseGrepQ params t =
potentially $ case t of
TC_Noary id _ token -> check id True token
TC_Unary id _ "-n" token -> check id True token
TC_Unary id _ "-z" token -> check id False token
_ -> fail "not check"
where
check id bool token = do
name <- getFinalGrep token
let op = if bool then "-n" else "-z"
let flip = if bool then "" else "! "
return . style id 2143 $
"Use " ++ flip ++ name ++ " -q instead of " ++
"comparing output with [ " ++ op ++ " .. ]."
getFinalGrep t = do
cmds <- getPipeline t
guard . not . null $ cmds
name <- getCommandBasename $ last cmds
guard . isGrep $ name
return name
getPipeline t =
case t of
T_NormalWord _ [x] -> getPipeline x
T_DoubleQuoted _ [x] -> getPipeline x
T_DollarExpansion _ [x] -> getPipeline x
T_Pipeline _ _ cmds -> return cmds
_ -> fail "unknown"
isGrep = (`elem` ["grep", "egrep", "fgrep", "zgrep"])
prop_checkTestGlobs1 = verify checkTestGlobs "[ -e *.mp3 ]"
prop_checkTestGlobs2 = verifyNot checkTestGlobs "[[ $a == *b* ]]"
checkTestGlobs params (TC_Unary _ _ op token) | isGlob token =
err (getId token) 2144 $
op ++ " doesn't work with globs. Use a for loop."
checkTestGlobs _ _ = return ()
prop_checkFindActionPrecedence1 = verify checkFindActionPrecedence "find . -name '*.wav' -o -name '*.au' -exec rm {} +"
prop_checkFindActionPrecedence2 = verifyNot checkFindActionPrecedence "find . -name '*.wav' -o \\( -name '*.au' -exec rm {} + \\)"
prop_checkFindActionPrecedence3 = verifyNot checkFindActionPrecedence "find . -name '*.wav' -o -name '*.au'"
checkFindActionPrecedence params = checkCommand "find" (const f)
where
pattern = [isMatch, const True, isParam ["-o", "-or"], isMatch, const True, isAction]
f list | length list < length pattern = return ()
f list@(_:rest) =
if all id (zipWith ($) pattern list)
then warnFor (list !! (length pattern - 1))
else f rest
isMatch = isParam [ "-name", "-regex", "-iname", "-iregex", "-wholename", "-iwholename" ]
isAction = isParam [ "-exec", "-execdir", "-delete", "-print", "-print0" ]
isParam strs t = fromMaybe False $ do
param <- getLiteralString t
return $ param `elem` strs
warnFor t = warn (getId t) 2146 "This action ignores everything before the -o. Use \\( \\) to group."
prop_checkFindExecWithSingleArgument1 = verify checkFindExecWithSingleArgument "find . -exec 'cat {} | wc -l' \\;"
prop_checkFindExecWithSingleArgument2 = verify checkFindExecWithSingleArgument "find . -execdir 'cat {} | wc -l' +"
prop_checkFindExecWithSingleArgument3 = verifyNot checkFindExecWithSingleArgument "find . -exec wc -l {} \\;"
checkFindExecWithSingleArgument _ = checkCommand "find" (const f)
where
f = void . sequence . mapMaybe check . tails
check (exec:arg:term:_) = do
execS <- getLiteralString exec
termS <- getLiteralString term
cmdS <- getLiteralStringExt (const $ return " ") arg
guard $ execS `elem` ["-exec", "-execdir"] && termS `elem` [";", "+"]
guard $ cmdS `matches` commandRegex
return $ warn (getId exec) 2150 "-exec does not invoke a shell. Rewrite or use -exec sh -c .. ."
check _ = Nothing
commandRegex = mkRegex "[ |;]"
prop_checkMaskedReturns1 = verify checkMaskedReturns "f() { local a=$(false); }"
prop_checkMaskedReturns2 = verify checkMaskedReturns "declare a=$(false)"
prop_checkMaskedReturns3 = verify checkMaskedReturns "declare a=\"`false`\""
prop_checkMaskedReturns4 = verifyNot checkMaskedReturns "declare a; a=$(false)"
prop_checkMaskedReturns5 = verifyNot checkMaskedReturns "f() { local -r a=$(false); }"
checkMaskedReturns _ t@(T_SimpleCommand id _ (cmd:rest)) = potentially $ do
name <- getCommandName t
guard $ name `elem` ["declare", "export"]
|| name == "local" && "r" `notElem` (map snd $ getAllFlags t)
return $ mapM_ checkArgs rest
where
checkArgs (T_Assignment id _ _ _ word) | any hasReturn $ getWordParts word =
warn id 2155 "Declare and assign separately to avoid masking return values."
checkArgs _ = return ()
hasReturn t = case t of
T_Backticked {} -> True
T_DollarExpansion {} -> True
_ -> False
checkMaskedReturns _ _ = return ()
prop_checkInjectableFindSh1 = verify checkInjectableFindSh "find . -exec sh -c 'echo {}' \\;"
prop_checkInjectableFindSh2 = verify checkInjectableFindSh "find . -execdir bash -c 'rm \"{}\"' ';'"
prop_checkInjectableFindSh3 = verifyNot checkInjectableFindSh "find . -exec sh -c 'rm \"$@\"' _ {} \\;"
checkInjectableFindSh _ = checkCommand "find" (const check)
where
check args = do
let idStrings = map (\x -> (getId x, onlyLiteralString x)) args
match pattern idStrings
match _ [] = return ()
match [] (next:_) = action next
match (p:tests) ((id, arg):args) = do
when (p arg) $ match tests args
match (p:tests) args
pattern = [
(`elem` ["-exec", "-execdir"]),
(`elem` ["sh", "bash", "ksh"]),
(== "-c")
]
action (id, arg) =
when ("{}" `isInfixOf` arg) $
warn id 2156 "Injecting filenames is fragile and insecure. Use parameters."
return []
runTests = $( [| $(forAllProperties) (quickCheckWithResult (stdArgs { maxSuccess = 1 }) ) |])