fhem.pl: add toJSON (by betateilchen for fheminfo, slightly modified)

git-svn-id: https://svn.fhem.de/fhem/trunk@14348 2b470e98-0d58-463d-a4d8-8e2adae1ed80

fhem/fhem.pl

@@ -134,6 +134,7 @@ sub redirectStdinStdErr();
 sub rejectDuplicate($$$);
 sub setGlobalAttrBeforeFork($);
 sub setReadingsVal($$$$);
+sub toJSON($);
 sub utf8ToLatin1($);
 
 sub CommandAttr($$);
@@ -4603,6 +4604,34 @@ sub escapeLogLine($) {
   return $s;
 }
 
+sub
+toJSON($)
+{
+  my $val = shift;
+
+  if(not defined $val) {
+    return "null";
+
+  } elsif (not ref $val) {
+    $val =~ s/([\x00-\x1f\x22\x5c\x7f])/sprintf '\u%04x', ord($1)/ge;
+
+    return '"' . $val . '"';
+
+  } elsif (ref $val eq 'ARRAY') {
+    return '[' . join(',', map toJSON($_), @$val) . ']';
+
+  } elsif (ref $val eq 'HASH') {
+      return '{' . join(',', 
+                   map { toJSON($_).":".toJSON($val->{$_}) } 
+                   sort keys %$val) . '}';
+
+  } else {
+      return toJSON("toJSON: Cannot encode $val");
+
+  }
+}
+
+
 sub
 Debug($) {
   my $msg= shift;
@@ -5056,4 +5085,5 @@ getPawList($)
   return @dob;
 }
 
+
 1;