数据转换-16进制字符

（一）在utils.h和utils.c中完成16进制字符'0'-'9','A'-'F','a'-'f'与十六进制数据0-15的转换功能

main.c

#include<stdio.h>
#include"utils.h"
int main(){
   //把整型数字转化为字节数组
  int p;
  char bytearr[100];
  printf("请输入一个整型数字\n");
  scanf("%d",&p);
  printf("把整型数转化为字节数组\n");
  INT2ByteArr(p,bytearr);
  printf("字节数组为%s\n",bytearr);
 
  //把字节数组转化为整型数字
  
  char barr[100];
  int h;
  printf("请输入一个字节数组:");
  scanf("%s",barr);
  printf("把字节数组转化为整型数字:");
  ByteArr2INT(barr,&h);
  printf("%d\n",h);
   

}

utils.c

#include<stdio.h>
#include"utils.h"
#include<string.h>
int Hex2Char(int fromi,char *toc)
{
    if(fromi>=0&&fromi<=9)
    {
        *toc= fromi+'0';
    } 
    else if(fromi>=10&&fromi<=15)
    {
        *toc = fromi+'A'-10;
    }
    else
    {
        printf("输入的16进制数据不正确！");
     }
    return 0;
}
int Char2Hex(char fromc,int *toi)
{
    if(fromc>='0'&& fromc<='9')
    {
             *toi= fromc-'0';
    }
    else if(fromc>='A'&& fromc<='F')
    {
             *toi= fromc-'A'+10;
    
        }
        else 
        {
            printf("输入的16进制字符不正确");
        }
    return 0;
}

int INT2ByteArr(int i,char *ba){
   int j;
   int a;
   int sum=0;
   int k=i;
   for(j=0;;j++)
   {
     k=k/16;
     if(k!=0)
      sum++;
     else
       break;
   }
   for(j=sum;j>=0;j--){
     a = i%16;
     Hex2Char(a,&ba[j]);
     i=i/16;   

   }
   ba[sum+1]='\0';


}
int ByteArr2INT(char *ba,int *i)
{
   int len;
   int j;
   int n=0;
   *i=0;
   len = strlen(ba);
   for(j=0;j<len;j++)
   {
      Char2Hex(ba[j],&n);
      //printf("%d\n",n);
      *i=(*i)*16+n;  

   }
   
}

（二）在utils.h和utils.c中完成位串与８位字节串的转换功能

utils1.h

#ifndef _UTIL_H_
#define _UTIL_H_

//char Hex2Char(int i);
//int Char2Hex(char c);

int Hex2Char(int fromi,char * toc);
int Char2Hex(char fromc,int * toi);

int Bitstr2ByteArr(char * bs,char * ba);
int ByteArr2Bitstr(char * ba,char * bs);

int Int2ByteArr(int i,char * ba);
int ByteArr2Int(char * ba,int * i);

#endif

utils1.c

#include<stdio.h>
#include"util.h"
char Hstr = {'0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F'};
char Hex2Char(int i){
if(i >= 0 && i <= 9){
return i + 0x30;
// return i + '0'
}
if(i >= 10 && i <= 15){
return i + 0x37;
// return i + 'A' - 10
}
return 0;
}

/*
int Hex2Char(int fromi,char *toc)
{
    if(fromi>=0&&fromi<=9)
    {
            *toc= fromi+'0';
    }
    else if(fromi>=10&&fromi<=15)
    {
            *toc = fromi+'A'-10;
    }
    else
    {
        printf("error");
     }
    return 0;
}
int Char2Hex(char fromc,int *toi)
{
        if(fromc>='0'&& fromc<='9')
        {
             *toi= fromc-'0';
        }
        else if(fromc>='A'&& fromc<='F')
        {
             *toi= fromc-'A'+10;

        }
        else
        {
            printf("error");
        }
        return 0;
}

*/

main1.c

#include<stdio.h>
#include"utils.h"
int main(){
  int n1,n2;
  char c1,c2;
  printf("请输入一个0~15的数：");
  scanf("%d",&n1);
  Hex2Char(n1,&c1);
  printf("对应的16进制字符是%c\n",c1);
  printf("请输入一个16进制字符：");
  scanf("%c",&c2);
  Char2Hex(c2,&n2);
  printf("%c对应的数是%d\n",c2,n2);
}