| 0 | If the operation was successful. Otherwise, a (negative) error code is returned. |
| -EINVAL | One or more of the supplied parameters are invalid. |
| -EPERM | parser has not been initialized. |
| -EOPNOTSUPP | Operation not supported for the type of value at the given index. |
| -ENODATA | The value at the given index is empty. |
| -ERANGE | Parsed integer value is out of range for the expected type. |
| -EBADMSG | The AT command string is malformed. |
| -EAGAIN | Parsing of the current AT command line is terminated and a subsequent line is available. Returned when index is greater than the maximum index for the current AT command line. |
| -EIO | There is nothing more to parse in the AT command string configured in parser. Returned when index is greater than the maximum index for the current AT command line. |