字符串中提取数字

int main(int argc, char** argv){   char str[] = ":SE:FR:STOP 38.2MHz";       char *p = str;   char temp[12];   int i = 0;    memset(temp, 0, sizeof(temp));   while( *p != '\0' )   {      if(isdigit(*p) || (*p == '.') )      {         temp[i++] = *p;      }      p++;   }   float num = atof(temp);    }