1BSON_JSON(3) Libbson BSON_JSON(3)
2
6 bson_json - JSON
7 Libbson provides routines for converting to and from the JSON format.
9 In particular, it supports the MongoDB extended JSON format.
10
12 There are often times where you might want to convert a BSON document
13 to JSON. It is convenient for debugging as well as an interchange for‐
14 mat. To help with this, Libbson contains the functions bson_as_canoni‐
15 cal_extended_json() and bson_as_relaxed_extended_json(). The canonical
16 format preserves BSON type information for values that may have ambigu‐
17 ous representations in JSON (e.g. numeric types).
18 bson_t *b;
20 size_t len;
21 char *str;
22 b = BCON_NEW ("a", BCON_INT32 (1));
24 str = bson_as_canonical_extended_json (b, &len);
26 printf ("%s\n", str);
27 bson_free (str);
28 bson_destroy (b);
30 { "a" : { "$numberInt": "1" } }
32 The relaxed format prefers JSON primitives for numeric values and may
34 be used if type fidelity is not required.
35 bson_t *b;
37 size_t len;
38 char *str;
39 b = BCON_NEW ("a", BCON_INT32 (1));
41 str = bson_as_relaxed_extended_json (b, &len);
43 printf ("%s\n", str);
44 bson_free (str);
45 bson_destroy (b);
47 { "a" : 1 }
49
51 Converting back from JSON is also useful and common enough that we
52 added bson_init_from_json() and bson_new_from_json().
53 The following example creates a new bson_t from the JSON string
55 {"a":1}.
56 bson_t *b;
58 bson_error_t error;
59 b = bson_new_from_json ("{\"a\":1}", -1, &error);
61 if (!b) {
63 printf ("Error: %s\n", error.message);
64 } else {
65 bson_destroy (b);
66 }
67
69 Libbson provides bson_json_reader_t to allow for parsing a sequence of
70 JSON documents into BSON. The interface is similar to bson_reader_t but
71 expects the input to be in the MongoDB extended JSON format.
72 /*
74 * Copyright 2013 MongoDB, Inc.
75 *
76 * Licensed under the Apache License, Version 2.0 (the "License");
77 * you may not use this file except in compliance with the License.
78 * You may obtain a copy of the License at
79 *
80 * http://www.apache.org/licenses/LICENSE-2.0
81 *
82 * Unless required by applicable law or agreed to in writing, software
83 * distributed under the License is distributed on an "AS IS" BASIS,
84 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
85 * See the License for the specific language governing permissions and
86 * limitations under the License.
87 */
88 /*
91 * This program will print each JSON document contained in the provided files
92 * as a BSON string to STDOUT.
93 */
94 #include <bson/bson.h>
97 #include <stdlib.h>
98 #include <stdio.h>
99 int
102 main (int argc, char *argv[])
103 {
104 bson_json_reader_t *reader;
105 bson_error_t error;
106 const char *filename;
107 bson_t doc = BSON_INITIALIZER;
108 int i;
109 int b;
110 /*
112 * Print program usage if no arguments are provided.
113 */
114 if (argc == 1) {
115 fprintf (stderr, "usage: %s FILE...\n", argv[0]);
116 return 1;
117 }
118 /*
120 * Process command line arguments expecting each to be a filename.
121 */
122 for (i = 1; i < argc; i++) {
123 filename = argv[i];
124 /*
126 * Open the filename provided in command line arguments.
127 */
128 if (0 == strcmp (filename, "-")) {
129 reader = bson_json_reader_new_from_fd (STDIN_FILENO, false);
130 } else {
131 if (!(reader = bson_json_reader_new_from_file (filename, &error))) {
132 fprintf (
133 stderr, "Failed to open \"%s\": %s\n", filename, error.message);
134 continue;
135 }
136 }
137 /*
139 * Convert each incoming document to BSON and print to stdout.
140 */
141 while ((b = bson_json_reader_read (reader, &doc, &error))) {
142 if (b < 0) {
143 fprintf (stderr, "Error in json parsing:\n%s\n", error.message);
144 abort ();
145 }
146 if (fwrite (bson_get_data (&doc), 1, doc.len, stdout) != doc.len) {
148 fprintf (stderr, "Failed to write to stdout, exiting.\n");
149 exit (1);
150 }
151 bson_reinit (&doc);
152 }
153 bson_json_reader_destroy (reader);
155 bson_destroy (&doc);
156 }
157 return 0;
159 }
160
162 The following example reads BSON documents from stdin and prints them
163 to stdout as JSON.
164 /*
166 * Copyright 2013 MongoDB, Inc.
167 *
168 * Licensed under the Apache License, Version 2.0 (the "License");
169 * you may not use this file except in compliance with the License.
170 * You may obtain a copy of the License at
171 *
172 * http://www.apache.org/licenses/LICENSE-2.0
173 *
174 * Unless required by applicable law or agreed to in writing, software
175 * distributed under the License is distributed on an "AS IS" BASIS,
176 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
177 * See the License for the specific language governing permissions and
178 * limitations under the License.
179 */
180 /*
183 * This program will print each BSON document contained in the provided files
184 * as a JSON string to STDOUT.
185 */
186 #include <bson/bson.h>
189 #include <stdio.h>
190 int
193 main (int argc, char *argv[])
194 {
195 bson_reader_t *reader;
196 const bson_t *b;
197 bson_error_t error;
198 const char *filename;
199 char *str;
200 int i;
201 /*
203 * Print program usage if no arguments are provided.
204 */
205 if (argc == 1) {
206 fprintf (stderr, "usage: %s [FILE | -]...\nUse - for STDIN.\n", argv[0]);
207 return 1;
208 }
209 /*
211 * Process command line arguments expecting each to be a filename.
212 */
213 for (i = 1; i < argc; i++) {
214 filename = argv[i];
215 if (strcmp (filename, "-") == 0) {
217 reader = bson_reader_new_from_fd (STDIN_FILENO, false);
218 } else {
219 if (!(reader = bson_reader_new_from_file (filename, &error))) {
220 fprintf (
221 stderr, "Failed to open \"%s\": %s\n", filename, error.message);
222 continue;
223 }
224 }
225 /*
227 * Convert each incoming document to JSON and print to stdout.
228 */
229 while ((b = bson_reader_read (reader, NULL))) {
230 str = bson_as_canonical_extended_json (b, NULL);
231 fprintf (stdout, "%s\n", str);
232 bson_free (str);
233 }
234 /*
236 * Cleanup after our reader, which closes the file descriptor.
237 */
238 bson_reader_destroy (reader);
239 }
240 return 0;
242 }
243
245 MongoDB, Inc
246
248 2017-present, MongoDB, Inc
2491.15.2 Nov 06, 2019 BSON_JSON(3)