如何删除字符数组中转换为无符号字符数组的警告

Hi i have the following code in c under Linux platform

你好，我在Linux平台下有以下c语言的代码

#include <stdio.h>
#include <string.h>

int main(void) {
  unsigned char client_id[8];
  char id[17] = "00000001";
  sscanf(id,"%02X%02X%02X%02X", &client_id[0], &client_id[1], &client_id[2], &client_id[3]);
  printf("%02X%02X%02X%02X", client_id[0], client_id[1], client_id[2], client_id[3]);
}

When I run this code I get the output

当我运行这段代码时，我得到了输出

00000001

but with following warning

但由于以下警告

> test.c: In function ‘main’: test.c:7:1: warning: format ‘%X’ expects
> argument of type ‘unsigned int *’, but argument 3 has type ‘unsigned
> char *’ [-Wformat=] 
> sscanf(id,"%02X%02X%02X%02X",&client_id[0],&client_id[1],&client_id[2],&client_id[3]);
> ^ test.c:7:1: warning: format ‘%X’ expects argument of type ‘unsigned
> int *’, but argument 4 has type ‘unsigned char *’ [-Wformat=]
> test.c:7:1: warning: format ‘%X’ expects argument of type ‘unsigned
> int *’, but argument 5 has type ‘unsigned char *’ [-Wformat=]
> test.c:7:1: warning: format ‘%X’ expects argument of type ‘unsigned
> int *’, but argument 6 has type ‘unsigned char *’ [-Wformat=]

The warnings are but obvious but how can I remove them?

这些警告是显而易见的，但我如何才能删除它们呢?

I do not want to use

我不想用

-Wno-pointer-sign

-Wno-pointer-sign

Should I use sprintf or any changes in sscanf?

我应该使用sprintf还是sscanf中的任何更改?

1 个解决方案

#1

You need to tell sscanf that the arguments are of a char type. This is done by putting the hh modifier before the X format specifier:

您需要告诉sscanf参数是char类型的。通过将hh修饰符放在X格式说明符之前完成:

sscanf(id,"%02hhX%02hhX%02hhX%02hhX",&client_id[0],&client_id[1],&client_id[2],&client_id[3]);