# mongoc_find_and_modify_opts_append()

## Synopsis

    bool
    mongoc_find_and_modify_opts_append (mongoc_find_and_modify_opts_t *opts,
                                        const bson_t *extra);

## Parameters

- `opts`: A mongoc_find_and_modify_opts_t.

- `extra`: A `bson_t` with fields and values to append directly to the findAndModify command sent to the server.

## Description

Adds arbitrary options to a findAndModify command.

`extra` does not have to remain valid after calling this function.

`extra` may be NULL or a BSON document with additional command options:

- `writeConcern`: Construct a mongoc_write_concern_t and use mongoc_write_concern_append() to add the write concern to `opts`. See the example code for mongoc_client_write_command_with_opts().

- `sessionId`: First, construct a mongoc_client_session_t with mongoc_client_start_session(). You can begin a transaction with mongoc_client_session_start_transaction(), optionally with a mongoc_transaction_opt_t that overrides the options inherited from `collection`, and use mongoc_client_session_append() to add the session to `opts`. See the example code for mongoc_client_session_t.

- `hint`: A document or string that specifies the index to use to support the query predicate.

- `let`: A BSON document consisting of any number of parameter names, each followed by definitions of constants in the MQL Aggregate Expression language.

- `comment`: A `bson_value_t` specifying the comment to attach to this command. The comment will appear in log messages, profiler output, and currentOp output. Requires MongoDB 4.4 or later.

## Returns

Returns true on success. If any arguments are invalid, returns false and logs an error.

## Appending options to findAndModify

opts.c

    void
    fam_opts (mongoc_collection_t *collection)
    {
       mongoc_find_and_modify_opts_t *opts;
       bson_t reply;
       bson_t *update;
       bson_error_t error;
       bson_t query = BSON_INITIALIZER;
       mongoc_write_concern_t *wc;
       bson_t extra = BSON_INITIALIZER;
       bool success;

       /* Find Zlatan Ibrahimovic, the striker */
       BSON_APPEND_UTF8 (&query, "firstname", "Zlatan");
       BSON_APPEND_UTF8 (&query, "lastname", "Ibrahimovic");
       BSON_APPEND_UTF8 (&query, "profession", "Football player");

       /* Bump his age */
       update = BCON_NEW ("$inc", "{", "age", BCON_INT32 (1), "}");

       opts = mongoc_find_and_modify_opts_new ();
       mongoc_find_and_modify_opts_set_update (opts, update);

       /* Abort if the operation takes too long. */
       mongoc_find_and_modify_opts_set_max_time_ms (opts, 100);

       /* Set write concern w: 2 */
       wc = mongoc_write_concern_new ();
       mongoc_write_concern_set_w (wc, 2);
       mongoc_write_concern_append (wc, &extra);

       /* Some future findAndModify option the driver doesn't support conveniently
        */
       BSON_APPEND_INT32 (&extra, "futureOption", 42);
       mongoc_find_and_modify_opts_append (opts, &extra);

       success = mongoc_collection_find_and_modify_with_opts (
          collection, &query, opts, &reply, &error);

       if (success) {
          char *str;

          str = bson_as_canonical_extended_json (&reply, NULL);
          printf ("%s\n", str);
          bson_free (str);
       } else {
          fprintf (
             stderr, "Got error: \"%s\" on line %d\n", error.message, __LINE__);
       }

       bson_destroy (&reply);
       bson_destroy (&extra);
       bson_destroy (update);
       bson_destroy (&query);
       mongoc_write_concern_destroy (wc);
       mongoc_find_and_modify_opts_destroy (opts);
    }