int gethostname()

in src/sagemaker_training/c/gethostname.c [29:88]

• 39 lines of code
• 6 McCabe index (conditional complexity)

int gethostname(char *name, size_t len)
{
    int r;
    FILE *file = fopen("/opt/ml/input/config/resourceconfig.json", "r");

    fseek(file, 0, SEEK_END);

    long length = ftell(file);
    fseek(file, 0, SEEK_SET);

    char *json_string = malloc(length + 1);
    fread(json_string, 1, length, file);
    fclose(file);
    json_string[length] = '\0';

    jsmn_parser parser;
    jsmntok_t token[1024];


    jsmn_init(&parser);
    r = jsmn_parse(&parser, json_string, strlen(json_string), token, sizeof(token) / sizeof(token[0]));


    if (r < 0) {
        printf("Failed to parse JSON: %d\n", r);
        return 1;
    }

    /* Assume the top-level element is an object */
    if (r < 1 || token[0].type != JSMN_OBJECT) {
        printf("Object expected\n");
        return 1;
    }

    /* Loop over all keys of the root object */
    int i;
    for (i = 1; i < r; i++)
    {
        if (jsoneq(json_string, &token[i], "current_host") == 0)
        {
            // strndup guarantees that val is null terminated. See https://linux.die.net/man/3/strndup
            char *val = strndup(json_string + token[i + 1].start, token[i + 1].end - token[i + 1].start);

            // Copy val into name. If strlen(val) > strlen(name) only len characters are copied
            strncpy(name, val, len);

            // As per posix (http://man7.org/linux/man-pages/man2/gethostname.2.html),
            // len is the size of the buffer, so we null terminate the last
            // position in the buffer
            name[len - 1] = '\0';

            free(val);
            free(json_string);
            return 0;
        }
    }

    free(json_string);
    return 1;
}