Parameter "--system=path" added to enable selection of Curry system for compilation of web script

scripts/MakeCGI.curry

@@ -8,21 +8,36 @@
 --- which does all the work.
 ---
 --- @author Michael Hanus
---- @version November 2018
+--- @version September 2019
 ------------------------------------------------------------------------------
 
 module MakeCGI
  where
 
+import Directory    ( doesFileExist )
 import Distribution ( installDir )
-import FilePath ( (</>) )
+import FilePath     ( (</>) )
+import List         ( isPrefixOf )
 import System
 
 import HTML.CGI.PackageConfig ( packagePath )
 
 main :: IO ()
 main = do
-  args <- getArgs
+  args0 <- getArgs
+  -- check whether option `--system=xxx` is provided:
+  let (args1,args2) = break ("--system=" `isPrefixOf`) args0
+      (root,args)  = if null args2
+                        then (installDir, args1)
+                        else (drop 9 (head args2), args1 ++ tail args2)
+  checkCurrySystem root
   rc <- system (unwords ((packagePath </> "scripts" </> "makecgi.sh") :
-                         map (\s -> '"' : s ++ "\"") (installDir : args)))
+                         map (\s -> '"' : s ++ "\"") (root : args)))
   exitWith rc
+
+checkCurrySystem :: String -> IO ()
+checkCurrySystem currydir = do
+  let currybin = currydir </> "bin" </> "curry"
+  isexec <- doesFileExist currybin
+  unless isexec $
+    error $ "Curry system executable '" ++ currybin ++ "' does not exist!"

scripts/makecgi.sh

@@ -83,7 +83,9 @@ if [ $# != 1 -a $# != 3 ] ; then
   echo "<curry>    : name of the Curry program (without suffix) containing the script"
   echo
   echo "FURTHER OPTIONS:"
-  echo '-Dname=val  : define (curry)rc property "name" as "val"'
+  echo "--system=path: set path to the root of Curry system"
+  echo "               (then 'path/bin/curry' is invoked to compile script)"
+  echo '-Dname=val   : define (curry)rc property "name" as "val"'
   echo "--cpmexec <c>: set the command to execute programs with the Curry Package"
   echo "               Manager (default: 'cypm exec')"
   echo "--compact    : reduce size of generated cgi program by deleting unused functions"
@@ -177,7 +179,7 @@ else
 fi
 
 # compile main module:
-echo "Generating saved state for initial expression: $MAIN"
+echo "Generating executable for initial expression: $MAIN"
 $CPMEXEC $CURRYROOT/bin/curry --nocypm $CURRYDOPTIONS $CURRYOPTIONS :l $MAINMOD :save $MAINCALL :q
 
 # now the file $MAINMOD should contain the executable computing the HTML form: