将下面代码中结构体的定义变为指针 #include <stdio.h> #include <stdlib.h> #include <string.h> #include <jansson.h> typedef struct { char vin[20]; long timestamp; char sdkVersion[128]; char deviceId[20]; } MyStruct; int main() { MyStruct s = { .vin = "12345", .timestamp = 1614279599, .sdkVersion = "1.0.0", .deviceId = "67890" }; // Convert struct to JSON json_t *root = json_object(); json_object_set_new(root, "vin", json_string(s.vin)); json_object_set_new(root, "timestamp", json_integer(s.timestamp)); json_object_set_new(root, "sdkVersion", json_string(s.sdkVersion)); json_object_set_new(root, "deviceId", json_string(s.deviceId)); char *json_str = json_dumps(root, JSON_INDENT(2)); printf("%s\n", json_str); // Clean up free(json_str); json_decref(root); return 0; }
时间: 2024-01-16 18:03:01 浏览: 29
下面是将结构体定义为指针并修改相关代码的示例:
```c
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <jansson.h>
typedef struct {
char vin[20];
long timestamp;
char sdkVersion[128];
char deviceId[20];
} *MyStructPtr;
int main() {
MyStructPtr s = malloc(sizeof(*s));
strcpy(s->vin, "12345");
s->timestamp = 1614279599;
strcpy(s->sdkVersion, "1.0.0");
strcpy(s->deviceId, "67890");
// Convert struct to JSON
json_t *root = json_object();
json_object_set_new(root, "vin", json_string(s->vin));
json_object_set_new(root, "timestamp", json_integer(s->timestamp));
json_object_set_new(root, "sdkVersion", json_string(s->sdkVersion));
json_object_set_new(root, "deviceId", json_string(s->deviceId));
char *json_str = json_dumps(root, JSON_INDENT(2));
printf("%s\n", json_str);
// Clean up
free(json_str);
json_decref(root);
free(s);
return 0;
}
```
在新代码中, `MyStruct` 被定义为指针类型 `MyStructPtr`,在 `main()` 函数中使用 `malloc()` 分配内存来创建 `MyStruct` 的实例,并使用 `->` 运算符来访问结构体成员。其余部分与之前的代码类似。
输出结果与之前的示例代码相同。
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