(7条消息) C字符串 与 uint32类型互相转换

  1. 字符串转换为 unsigned int 类型
/*将传入的字符串转换为无符号的的32位整形 *@param: str : 传入的字符串 *retval: The converted value.*/static unsigned int atoui(const char *str);unsigned int atoui(const char *str){    unsigned int result = 0, i = 0;    char *tmp = NULL;    for (i = 0; isspace(str[i]) && i < strlen(str); i++)//跳过空白符;            ;    tmp = str+i;    while (*tmp)    {        result = result * 10 + *tmp - '0';        tmp++;    }    return result;}

2. 将uint32 类型转换为 C字符串, 默认采用 10进制

char* uitoa(unsigned int n, char *s){    int i, j;    i = 0;    char buf[20];    memset(buf, 0, sizeof(buf));    do{        buf[i++] = n % 10 + '0';//取下一个数字    } while ((n /= 10)>0);//删除该数字       i -= 1;    for (j = 0; i >= 0; j++, i--)//生成的数字是逆序的，所以要逆序输出        s[j] = buf[i];    s[j] = '\0';        return s;}

3. 自定义LOG输出宏函数,

 #define myprint( x...) do {char bufMessagePut_Stdout_[1024];            sprintf(bufMessagePut_Stdout_, x);            fprintf(stdout, "%s [%d], [%s]\n", bufMessagePut_Stdout_,__LINE__, __FILE__ );    }while (0)    int main() {                myprint("The num : %d, The string : %s", 98, "nihao");             return 0; } //该函数宏要注意的地方: 宏中的局部参数: bufMessagePut_Stdout_, 不可以与外面的传进参数同名 ,同名时,宏替换会产生歧义:sprintf(bufMessagePut_Stdout_, "%s", bufMessagePut_Stdout_);此时: 前后bufMessagePut_Stdout_应代表不同的参数类型及意义,而程序上并不会这样认为.

4.将C风格 16进制的字符串 转换为十进制(即: 默认字符串中存的内容为 16进制数据)

//获取x的y次方; x^yunsigned int power(int x, int y){    unsigned int result = 1;    while (y--)        result *= x;    return result;}//将字符串的内容转换为 16进制unsigned int hex_conver_dec(char *src){    char *tmp = src;    int len = 0;    unsigned int hexad = 0;    char sub = 0;    while (1)    {        if (*tmp == '0')            //去除字符串 首位0        {            tmp++;            continue;        }                   else if (*tmp == 'X')        {            tmp++;            continue;        }        else if (*tmp == 'x')        {            tmp++;            continue;        }        else            break;    }    len = strlen(tmp);    for (len; len > 0; len--)    {                sub = toupper(*tmp++) - '0';        if (sub > 9)            sub -= 7;        hexad += sub * power(16, len - 1);          }    return hexad;}int main(){    hex_conver_dec("31");    //49    hex_conver_dec("abcd02");    //11259138}

5.在一块内存中查找子串位置：该函数主要是为了在二进制文本中进行查找操作。

//获取字符流中的指定子串的位置char* memstr(char* full_data, int full_data_len, char* substr) {      if (full_data == NULL || full_data_len <= 0 || substr == NULL) {          return NULL;      }      if (*substr == '\0') {          return NULL;      }      int sublen = strlen(substr);      int i;      char* cur = full_data;      int last_possible = full_data_len - sublen + 1;      for (i = 0; i < last_possible; i++) {          if (*cur == *substr) {              //assert(full_data_len - i >= sublen);               if (memcmp(cur, substr, sublen) == 0) {                  //found                   return cur;              }         }          cur++;      }                                                                                                                                                         return NULL; }

6. 查看指定目录下的文件是否存在

bool if_file_exist(const char *filePath){    if(filePath == NULL)        assert(0);    if(access(filePath, F_OK) == 0)        return true;    return false;}

7. 将unsigned int 转换为16进制C字符串

char *unsigned_int_to_hex(unsigned int number, char *hex_str){    char b[17] = { "0123456789ABCDEF" };    int c[8], i = 0, j = 0, d, base = 16;    do{        c[i] = number % base;        i++;        number = number / base;    } while (number != 0);    hex_str[j++] = '0';    hex_str[j++] = 'X';    for (--i ; i >= 0; --i, j++)    {        d = c[i];        hex_str[j] = b[d];    }    hex_str[j] = '\0';    return hex_str;}
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