1BSON_READER_T(3)                    libbson                   BSON_READER_T(3)
2
3
4
5Streaming BSON Document Reader
6

SYNOPSIS

8          #include <bson/bson.h>
9
10          typedef struct _bson_reader_t bson_reader_t;
11
12          bson_reader_t *
13          bson_reader_new_from_handle (void *handle,
14                                       bson_reader_read_func_t rf,
15                                       bson_reader_destroy_func_t df);
16          bson_reader_t *
17          bson_reader_new_from_fd (int fd, bool close_on_destroy);
18          bson_reader_t *
19          bson_reader_new_from_file (const char *path, bson_error_t *error);
20          bson_reader_t *
21          bson_reader_new_from_data (const uint8_t *data, size_t length);
22
23          void
24          bson_reader_destroy (bson_reader_t *reader);
25

DESCRIPTION

27       bson_reader_t  is a structure used for reading a sequence of BSON docu‐
28       ments. The sequence can come from a file-descriptor, memory region,  or
29       custom callbacks.
30

EXAMPLE

32          /*
33           * Copyright 2013 MongoDB, Inc.
34           *
35           * Licensed under the Apache License, Version 2.0 (the "License");
36           * you may not use this file except in compliance with the License.
37           * You may obtain a copy of the License at
38           *
39           *   http://www.apache.org/licenses/LICENSE-2.0
40           *
41           * Unless required by applicable law or agreed to in writing, software
42           * distributed under the License is distributed on an "AS IS" BASIS,
43           * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
44           * See the License for the specific language governing permissions and
45           * limitations under the License.
46           */
47
48
49          /*
50           * This program will print each BSON document contained in the provided files
51           * as a JSON string to STDOUT.
52           */
53
54
55          #include <bson/bson.h>
56          #include <stdio.h>
57
58
59          int
60          main (int argc, char *argv[])
61          {
62             bson_reader_t *reader;
63             const bson_t *b;
64             bson_error_t error;
65             const char *filename;
66             char *str;
67             int i;
68
69             /*
70              * Print program usage if no arguments are provided.
71              */
72             if (argc == 1) {
73                fprintf (stderr, "usage: %s [FILE | -]...\nUse - for STDIN.\n", argv[0]);
74                return 1;
75             }
76
77             /*
78              * Process command line arguments expecting each to be a filename.
79              */
80             for (i = 1; i < argc; i++) {
81                filename = argv[i];
82
83                if (strcmp (filename, "-") == 0) {
84                   reader = bson_reader_new_from_fd (STDIN_FILENO, false);
85                } else {
86                   if (!(reader = bson_reader_new_from_file (filename, &error))) {
87                      fprintf (
88                         stderr, "Failed to open \"%s\": %s\n", filename, error.message);
89                      continue;
90                   }
91                }
92
93                /*
94                 * Convert each incoming document to JSON and print to stdout.
95                 */
96                while ((b = bson_reader_read (reader, NULL))) {
97                   str = bson_as_canonical_extended_json (b, NULL);
98                   fprintf (stdout, "%s\n", str);
99                   bson_free (str);
100                }
101
102                /*
103                 * Cleanup after our reader, which closes the file descriptor.
104                 */
105                bson_reader_destroy (reader);
106             }
107
108             return 0;
109          }
110

AUTHOR

112       MongoDB, Inc
113

115       2017-present, MongoDB, Inc
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1201.25.1                           Nov 08, 2023                 BSON_READER_T(3)
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