# bson_json_reader_t

## Bulk JSON to BSON conversion

## Synopsis

    #include <bson.h>

    typedef struct _bson_json_reader_t bson_json_reader_t;

    typedef enum
    {
       BSON_JSON_ERROR_READ_CORRUPT_JS = 1,
       BSON_JSON_ERROR_READ_INVALID_PARAM,
       BSON_JSON_ERROR_READ_CB_FAILURE,
    } bson_json_error_code_t;

## Description

The bson_json_reader_t structure is used for reading a sequence of JSON documents and transforming them to bson_t documents.

This can often be useful if you want to perform bulk operations that are defined in a file containing JSON documents.

bson_json_reader_t works upon JSON documents formatted in MongoDB extended JSON format.

## 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 JSON document contained in the provided files
     * as a BSON string to STDOUT.
     */

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

    int
    main (int   argc,
          char *argv[])
    {
       bson_json_reader_t *reader;
       bson_error_t error;
       const char *filename;
       bson_t doc = BSON_INITIALIZER;
       int i;
       int b;

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

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

          /*
           * Open the filename provided in command line arguments.
           */
          if (0 == strcmp (filename, "-")) {
             reader = bson_json_reader_new_from_fd (STDIN_FILENO, false);
          } else {
             if (!(reader = bson_json_reader_new_from_file (filename, &error))) {
                fprintf (stderr, "Failed to open \"%s\": %s\n",
                         filename, error.message);
                continue;
             }
          }

          /*
           * Convert each incoming document to BSON and print to stdout.
           */
          while ((b = bson_json_reader_read (reader, &doc, &error))) {
             if (b < 0) {
                fprintf (stderr, "Error in json parsing:\n%s\n", error.message);
                abort ();
             }

             if (fwrite (bson_get_data(&doc), 1, doc.len, stdout) != doc.len) {
                fprintf (stderr, "Failed to write to stdout, exiting.\n");
                exit (1);
             }
             bson_reinit (&doc);
          }

          bson_json_reader_destroy (reader);
          bson_destroy (&doc);
       }

       return 0;
    }