十六进制与ascii码互转 C语言实现

曾经终败给现在 2022-12-18 13:56 194阅读 0赞

十六进制与ascii码互转 C语言实现

1. ascii转16进制

/**
     * func  : char_to_hex()
     * desc  : convert ascii to 16 hex
     * input : ascii
     * return: hex
     */
    unsigned char char_to_hex(unsigned char chr)
    {
        if((chr>='0')&&(chr<='9'))
            chr = 0x30+(chr-'0');
        else if((chr>='A')&&(chr<='Z'))//capital
            chr = 0x41+(chr - 'A');
        else if((chr>='a')&&(chr<='z'))//little
            chr = 0x61+(chr-'a');
        else
            chr = 0xff;
        return chr;
    }

2.  16进制转ascii

/**
     * func  ：hex_to_char() 
     * desc  ：transform hex to ascii 
     * input ：hex 
     * return：ascii
     */
    unsigned char hex_to_char(unsigned char hex)
    {
        if((hex>=0x30)&&(hex<=0x39))
            hex = hex-0x30;
        else if((hex>=0x41)&&(hex<=0x5A)) // capital
            hex = 'A' + (hex - 0x41);
        else if((hex>=0x61)&&(hex<=0x7A)) // little case
            hex = 'a' + (hex - 0x61);
        else 
            hex = 0xff;
        return hex;
    }

3. 验证

int main(void)
    {
    #if 0
        unsigned char chr = 'x';
        unsigned char hex = 0x45;
        unsigned char buff = 0xff;
    
        buff = hex_to_char(hex);
        printf("hex_to_char:%c\n", buff);
        
        buff = char_to_hex(chr);
        printf("0x%02x\n",buff);
    #else
        unsigned char str[] = "hello";
        unsigned char hex[4] = {0x61,0x62,0x41,0x42};
        unsigned char buff[32] = {0};
        int i,len;
    
        len = strlen(str);
        for(i = 0; i < len; i++)
            buff[i] =char_to_hex(str[i]);
        for(i = 0;i < len; i++)
            printf("char_to_hex:0x%02x\n",buff[i]);
    
        for(i = 0; i < 4; i++) 
            buff[i] = hex_to_char(hex[i]);
        buff[4] = '\0';
        printf("hex_to_char:%s\n",buff);
    #endif
        return 0;
    }

执行结果：

![20201027014830283.png][]

[20201027014830283.png]: /images/20221122/eccf05d50c3f422fb3a56a28dcec210c.png