fix: [0km] allow NUL characters to be sent to inner sub command when muxing

Signed-off-by: Valentin Lab <valentin.lab@kalysto.org>

bin/0km

@@ -265,13 +265,14 @@ vps_mux() {
         [ "$max_size" -lt "${size_name}" ] &&
             max_size="$size_name"
     done
-    code=$(cat)
+    settmpdir "_0KM_TMP_DIR"
+    cat > "$_0KM_TMP_DIR/code"
     for vps in "${new_vps[@]}"; do
         label=$(printf "%-${max_size}s" "$vps")
         (
             {
                 {
-                    echo "$code" | "$fn" "$vps"
+                     "$fn" "$vps" < "$_0KM_TMP_DIR/code"
                 } 3>&1 1>&2 2>&3 | sed -r "s/^/$DARKCYAN$label$NORMAL $DARKRED\!$NORMAL /g"
                 set_errlvl "${PIPESTATUS[0]}"
             } 3>&1 1>&2 2>&3  | sed -r "s/^/$DARKCYAN$label$NORMAL $DARKGRAY\|$NORMAL /g"