-xpns_load_arg_options() {
-  # Extract flag options only.
-  local _pattern=
-  xpns_load_flag_options "$(xpns_extract_matched "$1" "^-${XP_FLAG_OPTIONS}+")" > /dev/null
-  if [[ "$1" =~ ^-${XP_FLAG_OPTIONS}*I ]]; then
-    # Behavior like this.
-    # -IAAA       -- XP_REPSTR="AAA"
-    # -I AAA BBB  -- XP_REPSTR="AAA", XP_ARGS=("BBB")
-    # -I"AAA BBB" -- XP_REPSTR="AAA BBB"
-    # -IAAA BBB   -- XP_REPSTR="AAA", XP_ARGS=("BBB")
-    # -I -d ...   -- XP_REPSTR=""
-    _pattern="^-${XP_FLAG_OPTIONS}*I(.+)"
-    if [[ "$1" =~ $_pattern ]]; then
-      XP_REPSTR="${BASH_REMATCH[1]}"
-      return 0
-    elif ! [[ "$2" =~ ^-.* ]]; then
-      XP_REPSTR="$2"
-      return 0
-    else
-      xpns_msg_error "invalid argument '$2' for -I option"
-      exit ${XP_EINVAL}
-    fi
-  elif [[ "$1" =~ ^-${XP_FLAG_OPTIONS}*l ]]; then
-    _pattern="^-${XP_FLAG_OPTIONS}*l(.+)"
-    if [[ "$1" =~ $_pattern ]]; then
-      XP_OPT_USE_PRESET_LAYOUT=1
-      XP_LAYOUT="$(cat <<<"${BASH_REMATCH[1]}" | xpns_layout_short2long)"
-      xpns_is_valid_layout "${XP_LAYOUT}"
-      return 0
-    elif ! [[ "$2" =~ ^-.* ]]; then
-      XP_OPT_USE_PRESET_LAYOUT=1
-      XP_LAYOUT="$(cat <<<"$2" |  xpns_layout_short2long )"
-      xpns_is_valid_layout "${XP_LAYOUT}"
-      return 0
-    else
-      xpns_msg_error "invalid argument '$2' for -l option"
-      exit ${XP_EINVAL}
-    fi
-  elif [[ "$1" =~ ^-${XP_FLAG_OPTIONS}*c ]]; then
-    _pattern="^-${XP_FLAG_OPTIONS}*c(.+)"
-    if [[ "$1" =~ $_pattern ]]; then
-      XP_CMD_UTILITY="${BASH_REMATCH[1]}"
-      XP_OPT_CMD_UTILITY=1
-      return 0
-    elif ! [[ "$2" =~ ^-.* ]]; then
-      XP_CMD_UTILITY="$2"
-      XP_OPT_CMD_UTILITY=1
-      return 0
-    else
-      xpns_msg_error "invalid argument '$2' for -c option"
-      exit ${XP_EINVAL}
-    fi
-  elif [[ "$1" =~ ^-${XP_FLAG_OPTIONS}*n ]]; then
-    _pattern="^-${XP_FLAG_OPTIONS}*n([0-9]+)"
-    if [[ "$1" =~ $_pattern ]]; then
-      XP_MAX_PANE_ARGS="${BASH_REMATCH[1]}"
-      return 0
-    elif [[ "$2" =~ ^[0-9]+$ ]]; then
-      XP_MAX_PANE_ARGS="$2"
-      return 0
-    else
-      xpns_msg_error "invalid argument '$2' for -n option"
-      exit ${XP_EINVAL}
-    fi
-  elif [[ "$1" =~ ^-${XP_FLAG_OPTIONS}*S ]]; then
-    _pattern="^-${XP_FLAG_OPTIONS}*S(.+)"
-    if [[ "$1" =~ $_pattern ]]; then
-      XP_SOCKET_PATH="${BASH_REMATCH[1]}"
-      return 0
-    elif ! [[ "$2" =~ ^-.* ]]; then
-      XP_SOCKET_PATH="$2"
-      return 0
-    else
-      xpns_msg_error "invalid argument '$2' for -S option"
-      exit ${XP_EINVAL}
-    fi
-  elif [[ "$1" =~ ^-${XP_FLAG_OPTIONS}*C ]]; then
-    _pattern="^-${XP_FLAG_OPTIONS}*C([0-9]+)"
-    if [[ "$1" =~ $_pattern ]]; then
-      XP_OPT_CUSTOM_SIZE_COLS="${BASH_REMATCH[1]}"
-      return 0
-    elif [[ "$2" =~ ^[0-9]+$ ]];then
-      XP_OPT_CUSTOM_SIZE_COLS="$2"
-      return 0
-    else
-      xpns_msg_error "invalid argument '$2' for -C option"
-      exit ${XP_EINVAL}
-    fi
-  elif [[ "$1" =~ ^-${XP_FLAG_OPTIONS}*R ]]; then
-    _pattern="^-${XP_FLAG_OPTIONS}*R([0-9]+)"
-    if [[ "$1" =~ $_pattern ]]; then
-      XP_OPT_CUSTOM_SIZE_ROWS="${BASH_REMATCH[1]}"
-      return 0
-    elif [[ "$2" =~ ^[0-9]+$ ]];then
-      XP_OPT_CUSTOM_SIZE_ROWS="$2"
-      return 0
-    else
-      xpns_msg_error "invalid argument '$2' for -R option"
-      exit ${XP_EINVAL}
-    fi
-  elif [[ "$1" =~ ^-${XP_FLAG_OPTIONS}*B ]]; then
-    _pattern="^-${XP_FLAG_OPTIONS}*B(.+)"
-    if [[ "$1" =~ $_pattern ]]; then
-      XP_BEGIN_ARGS+=("${BASH_REMATCH[1]}")
-      return 0
-    else
-      XP_BEGIN_ARGS+=("$2")
-      return 0
-    fi