support de la syntaxe ?=

ulib/crontab

@@ -151,9 +151,9 @@ BEGIN {
   match_indented = 0
 }
 
-/^(export[ \t]+)?[a-zA-Z_][a-zA-Z0-9_]*[-+%#]=/ {
+/^(export[ \t]+)?[a-zA-Z_][a-zA-Z0-9_]*[-+%#?]=/ {
   # manipulation de variables de type PATH
-  match($0, /^(export[ \t]+)?([a-zA-Z_][a-zA-Z0-9_]*)([-+%#])=(.*)$/, parts)
+  match($0, /^(export[ \t]+)?([a-zA-Z_][a-zA-Z0-9_]*)([-+%#?])=(.*)$/, parts)
   name = parts[2]
   type = parts[3]
   value = parts[4]
@@ -163,6 +163,8 @@ BEGIN {
     print "uinspath " value " " name
   } else if (type == "-") {
     print "udelpath " value " " name
+  } else if (type == "?") {
+    print "[ -n \"$" name "\" ] || " name "=" value
   }
   print "export " name
   next