1 /*
2 * Copyright (c) 2014-2020 Pavel Kalvoda <me@pavelkalvoda.com>
3 *
4 * libcbor is free software; you can redistribute it and/or modify
5 * it under the terms of the MIT license. See LICENSE for details.
6 */
7
8 #include <stdio.h>
9 #include "cbor.h"
10
usage(void)11 void usage(void) {
12 printf("Usage: readfile [input file]\n");
13 exit(1);
14 }
15
16 /*
17 * Reads data from a file. Example usage:
18 * $ ./examples/readfile examples/data/nested_array.cbor
19 */
20
main(int argc,char * argv[])21 int main(int argc, char* argv[]) {
22 if (argc != 2) usage();
23 FILE* f = fopen(argv[1], "rb");
24 if (f == NULL) usage();
25 fseek(f, 0, SEEK_END);
26 size_t length = (size_t)ftell(f);
27 fseek(f, 0, SEEK_SET);
28 unsigned char* buffer = malloc(length);
29 fread(buffer, length, 1, f);
30
31 /* Assuming `buffer` contains `length` bytes of input data */
32 struct cbor_load_result result;
33 cbor_item_t* item = cbor_load(buffer, length, &result);
34 free(buffer);
35
36 if (result.error.code != CBOR_ERR_NONE) {
37 printf(
38 "There was an error while reading the input near byte %zu (read %zu "
39 "bytes in total): ",
40 result.error.position, result.read);
41 switch (result.error.code) {
42 case CBOR_ERR_MALFORMATED: {
43 printf("Malformed data\n");
44 break;
45 }
46 case CBOR_ERR_MEMERROR: {
47 printf("Memory error -- perhaps the input is too large?\n");
48 break;
49 }
50 case CBOR_ERR_NODATA: {
51 printf("The input is empty\n");
52 break;
53 }
54 case CBOR_ERR_NOTENOUGHDATA: {
55 printf("Data seem to be missing -- is the input complete?\n");
56 break;
57 }
58 case CBOR_ERR_SYNTAXERROR: {
59 printf(
60 "Syntactically malformed data -- see "
61 "https://www.rfc-editor.org/info/std94\n");
62 break;
63 }
64 case CBOR_ERR_NONE: {
65 // GCC's cheap dataflow analysis gag
66 break;
67 }
68 }
69 exit(1);
70 }
71
72 /* Pretty-print the result */
73 cbor_describe(item, stdout);
74 fflush(stdout);
75 /* Deallocate the result */
76 cbor_decref(&item);
77
78 fclose(f);
79 }
80