Provided by: libmongoc-doc_1.15.0-1_all bug


       mongoc_cursor_t - mongoc_cursor_t

       Client-side cursor abstraction


          typedef struct _mongoc_cursor_t mongoc_cursor_t;

       mongoc_cursor_t  provides access to a MongoDB query cursor.  It wraps up the wire protocol
       negotiation required to initiate a query and retrieve an unknown number of documents.

       Common cursor operations include:

       · Determine which host we've connected to with mongoc_cursor_get_host().

       · Retrieve more records with repeated calls to mongoc_cursor_next().

       · Clone a query to repeat execution at a later point with mongoc_cursor_clone().

       · Test for errors with mongoc_cursor_error().

       Cursors are lazy, meaning that no connection is established and no network traffic  occurs
       until the first call to mongoc_cursor_next().


       mongoc_cursor_t is NOT thread safe. It may only be used from within the thread in which it
       was created.


       Query MongoDB and iterate results

          /* gcc example-client.c -o example-client $(pkg-config --cflags --libs
           * libmongoc-1.0) */

          /* ./example-client [CONNECTION_STRING [COLLECTION_NAME]] */

          #include <mongoc/mongoc.h>
          #include <stdio.h>
          #include <stdlib.h>

          main (int argc, char *argv[])
             mongoc_client_t *client;
             mongoc_collection_t *collection;
             mongoc_cursor_t *cursor;
             bson_error_t error;
             const bson_t *doc;
             const char *collection_name = "test";
             bson_t query;
             char *str;
             const char *uri_string = "mongodb://";
             mongoc_uri_t *uri;

             mongoc_init ();
             if (argc > 1) {
                uri_string = argv[1];

             if (argc > 2) {
                collection_name = argv[2];

             uri = mongoc_uri_new_with_error (uri_string, &error);
             if (!uri) {
                fprintf (stderr,
                         "failed to parse URI: %s\n"
                         "error message:       %s\n",
                return EXIT_FAILURE;

             client = mongoc_client_new_from_uri (uri);
             if (!client) {
                return EXIT_FAILURE;

             mongoc_client_set_error_api (client, 2);

             bson_init (&query);

          #if 0
             bson_append_utf8 (&query, "hello", -1, "world", -1);

             collection = mongoc_client_get_collection (client, "test", collection_name);
             cursor = mongoc_collection_find_with_opts (
                NULL,  /* additional options */
                NULL); /* read prefs, NULL for default */

             while (mongoc_cursor_next (cursor, &doc)) {
                str = bson_as_canonical_extended_json (doc, NULL);
                fprintf (stdout, "%s\n", str);
                bson_free (str);

             if (mongoc_cursor_error (cursor, &error)) {
                fprintf (stderr, "Cursor Failure: %s\n", error.message);
                return EXIT_FAILURE;

             bson_destroy (&query);
             mongoc_cursor_destroy (cursor);
             mongoc_collection_destroy (collection);
             mongoc_uri_destroy (uri);
             mongoc_client_destroy (client);
             mongoc_cleanup ();

             return EXIT_SUCCESS;


       MongoDB, Inc


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