arg-parser -- fix utf8

helpers/arg-parser/args.sh

@@ -13,7 +13,7 @@
 #exitcode	0 - string valid
 #exitcode	1 - string is not valid
 grep_match() {
-    printf "%s" "$1" | grep -qP "$2" >/dev/null
+    printf "%s" "$1" | grep -qE "$2" >/dev/null
 }
 
 #purpose	Find short argument or its value