Alias ash to dash with warning.

ShellCheck/Analytics.hs

@@ -400,15 +400,20 @@ prop_checkShebang1 = verifyNotTree checkShebang "#!/usr/bin/env bash -x\necho co
 prop_checkShebang2 = verifyNotTree checkShebang "#! /bin/sh  -l "
 prop_checkShebang3 = verifyTree checkShebang "ls -l"
 prop_checkShebang4 = verifyNotTree checkShebang "#shellcheck shell=sh\nfoo"
+prop_checkShebang5 = verifyTree checkShebang "#!/usr/bin/env ash"
+prop_checkShebang6 = verifyNotTree checkShebang "#!/usr/bin/env ash\n# shellcheck shell=dash\n"
+prop_checkShebang7 = verifyNotTree checkShebang "#!/usr/bin/env ash\n# shellcheck shell=sh\n"
 checkShebang params (T_Annotation _ list t) =
     if any isOverride list then [] else checkShebang params t
   where
     isOverride (ShellOverride _) = True
     isOverride _ = False
-checkShebang params (T_Script id sb _) =
-    [makeComment ErrorC id 2148
-        "Tips depend on target shell and yours is unknown. Add a shebang."
-      | not (shellTypeSpecified params) && sb == "" ]
+checkShebang params (T_Script id sb _) = execWriter $
+    unless (shellTypeSpecified params) $ do
+        when (sb == "") $
+            err id 2148 "Tips depend on target shell and yours is unknown. Add a shebang."
+        when (executableFromShebang sb == "ash") $
+            warn id 2187 "Ash scripts will be checked as Dash. Add '# shellcheck shell=dash' to silence."
 
 
 prop_checkForInQuoted = verify checkForInQuoted "for f in \"$(ls)\"; do echo foo; done"

ShellCheck/AnalyzerLib.hs

@@ -153,6 +153,7 @@ prop_determineShell4 = determineShell (fromJust $ pScript
 prop_determineShell5 = determineShell (fromJust $ pScript
     "#shellcheck shell=sh\nfoo") == Sh
 prop_determineShell6 = determineShell (fromJust $ pScript "#! /bin/sh") == Sh
+prop_determineShell7 = determineShell (fromJust $ pScript "#! /bin/ash") == Dash
 determineShell t = fromMaybe Bash $ do
     shellString <- foldl mplus Nothing $ getCandidates t
     shellForExecutable shellString
@@ -166,8 +167,13 @@ determineShell t = fromMaybe Bash $ do
     getCandidates (T_Annotation _ annotations s) =
         map forAnnotation annotations ++
            [Just $ fromShebang s]
-    fromShebang (T_Script _ s t) = shellFor s
+    fromShebang (T_Script _ s t) = executableFromShebang s
 
+-- Given a string like "/bin/bash" or "/usr/bin/env dash",
+-- return the shell basename like "bash" or "dash"
+executableFromShebang :: String -> String
+executableFromShebang = shellFor
+  where
     shellFor s | "/env " `isInfixOf` s = head (drop 1 (words s)++[""])
     shellFor s | ' ' `elem` s = shellFor $ takeWhile (/= ' ') s
     shellFor s = reverse . takeWhile (/= '/') . reverse $ s

ShellCheck/Data.hs

@@ -88,6 +88,7 @@ shellForExecutable name =
         "sh"    -> return Sh
         "bash"  -> return Bash
         "dash"  -> return Dash
+        "ash"   -> return Dash -- There's also a warning for this.
         "ksh"   -> return Ksh
         "ksh88" -> return Ksh
         "ksh93" -> return Ksh

nextnumber

@@ -0,0 +1,10 @@
+#!/bin/bash
+# TODO: Find a less trashy way to get the next available error code
+
+shopt -s globstar
+
+for i in 1 2
+do
+  last=$(grep -hv "^prop" **/*.hs | grep -Ewo "$i[0-9]{3}" | sort -n | tail -n 1)
+  echo "Next ${i}xxx: $((last+1))"
+done