BSON_READER_T(3)

NAME
bson_reader_t - bson_reader_t

Streaming BSON Document Reader

SYNOPSIS

        #include <bson/bson.h>

        typedef struct _bson_reader_t bson_reader_t;

        bson_reader_t *
        bson_reader_new_from_handle (void *handle,
                                     bson_reader_read_func_t rf,
                                     bson_reader_destroy_func_t df);
        bson_reader_t *
        bson_reader_new_from_fd (int fd, bool close_on_destroy);
        bson_reader_t *
        bson_reader_new_from_file (const char *path, bson_error_t *error);
        bson_reader_t *
        bson_reader_new_from_data (const uint8_t *data, size_t length);

        void
        bson_reader_destroy (bson_reader_t *reader);

DESCRIPTION

bson_reader_t is a structure used for reading a sequence of BSON documents. The sequence can come from a file-descriptor, memory region, or custom callbacks.

EXAMPLE

        /*
         * Copyright 2013 MongoDB, Inc.
         *
         * Licensed under the Apache License, Version 2.0 (the "License");
         * you may not use this file except in compliance with the License.
         * You may obtain a copy of the License at
         *
         *   http://www.apache.org/licenses/LICENSE-2.0
         *
         * Unless required by applicable law or agreed to in writing, software
         * distributed under the License is distributed on an "AS IS" BASIS,
         * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
         * See the License for the specific language governing permissions and
         * limitations under the License.
         */

        /*
         * This program will print each BSON document contained in the provided files
         * as a JSON string to STDOUT.
         */

        #include <bson/bson.h>
        #include <stdio.h>

        int
        main (int argc, char *argv[])
        {
           bson_reader_t *reader;
           const bson_t *b;
           bson_error_t error;
           const char *filename;
           char *str;
           int i;

           /*
            * Print program usage if no arguments are provided.
            */
           if (argc == 1) {
              fprintf (stderr, "usage: %s [FILE | -]...\nUse - for STDIN.\n", argv[0]);
              return 1;
           }

           /*
            * Process command line arguments expecting each to be a filename.
            */
           for (i = 1; i < argc; i++) {
              filename = argv[i];

              if (strcmp (filename, "-") == 0) {
                 reader = bson_reader_new_from_fd (STDIN_FILENO, false);
              } else {
                 if (!(reader = bson_reader_new_from_file (filename, &error))) {
                    fprintf (
                       stderr, "Failed to open \"%s\": %s\n", filename, error.message);
                    continue;
                 }
              }

              /*
               * Convert each incoming document to JSON and print to stdout.
               */
              while ((b = bson_reader_read (reader, NULL))) {
                 str = bson_as_canonical_extended_json (b, NULL);
                 fprintf (stdout, "%s\n", str);
                 bson_free (str);
              }

              /*
               * Cleanup after our reader, which closes the file descriptor.
               */
              bson_reader_destroy (reader);
           }

           return 0;
        }

AUTHOR
MongoDB, Inc

COPYRIGHT
2017-present, MongoDB, Inc