hexToAscii AsciitoHex 网上收集

//
//eg1:hexToAscii
//
#include <stdio.h>
#include <stdlib.h>

/*
* To convert 53 to the character 'S':
* char returnVal = hexToString('5', '3');
*/
char hexToAscii(char first, char second)
{
　char hex[5], *stop;
　hex[0] = '0';
  hex[1] = 'x';
  hex[2] = first;
  hex[3] = second;
  hex[4] = 0;
  return　 strtol(hex, &stop, 16);
}

int main(int argc, char* argv[])
{
 printf("%c/n", hexToAscii('5', '3'));
}

//
//eg2:AsciitoHex  in C
//

#include <stdio.h>

void text_to_hex(char *is_ascii_string, char *os_hex_string, int ii_ascii_string_size);

int main()
{
   FILE *pf_in_file  = NULL;
   char ps_in_filename[20] = "";
   int  pi_input_chunk_size  = 0;
   char ps_input_chunk[161] = "";
   long pl_bytes_to_read = 160;
   char ls_input_chunk_raw[220] = "";

   strcpy(ps_input_chunk, "<8f><80>âY^SZÃpS  ðï^Y");
   pi_input_chunk_size = strlen(ps_input_chunk);

   printf("INput chunk   = [%s]/n", ps_input_chunk);
   printf("Read buf size = [%d]/n", pi_input_chunk_size);

   text_to_hex(ps_input_chunk, ls_input_chunk_raw, pi_input_chunk_size);

   printf("ls_input_chunk_raw = [%s]/n", ls_input_chunk_raw);

   return (0);
}

void text_to_hex(char *is_ascii_string, char *os_hex_string, int ii_ascii_string_size)
{
   char *function = "text_to_hex";

   char   ls_hex[3] = "";
   int    i = 0;
   int    j = 0;

   memset(ls_hex, '/0', 3);

   j = 0;
   for (i=0; i < ii_ascii_string_size; i++)
   {
      sprintf(ls_hex, "%.2X", is_ascii_string[i]);

      os_hex_string[j++] = ls_hex[0];
      os_hex_string[j++] = ls_hex[1];
   }

   os_hex_string[j] = '/0';

}
 

///
//eg3.Convert the Ascii to Hex in C
///
int main()
{
    char symbols [] = "0123456789abcdef";
    char result [4];
    unsigned i, j, lsd, hexNum;
    for (i = 0; i < 256; ++i)
    {
        hexNum = i;
        j = 0;
        strcpy (result, "0");
        do
        {
            lsd = hexNum % 16;
            result [j++] = symbols [lsd];
            hexNum /= 16;
        } while (hexNum);
        result [j] = '/0';
        printf ("Hex: %s/n", _strrev (result));
    }
    return (0);
}
 

///
//eg4.
///
cout<<hex<<(int)'tian'<<endl;//貌似这样也行。。
 
///
//eg5. Transform a word into ASCII code
///

#include <iostream>
using namespace std;
int main()
{
    char word[32];
    int x = 0;
    cout << "Please enter the word (maximum 32 characters):/n";
    cin >> word;
    cout << "The ASCII for this word is:/n";
    while (word[x] != '/0')    // While the string isn't at the end...
    {
        cout << int(word[x]);    // Transform the char to int
        x++;
    }
    cout << "/n";
    return 0;
}

///
//eg6.
///
#include <iostream>
#include <string>
#include <sstream>
#include <iomanip>

using namespace std;

int main()
{
 string val("54657374");
 stringstream ss(val);
 long l;
 ss >hex >l;
 cout << "val ='" << val << "', l = " << l << ", hex(l) ='" << hex << l << "'"<< endl;
 return 0;
}

///
//eg6. If you want to convert hex string into a number use strtol()
///
#include <cstdlib>
#include <cstdio>

using namespace std;

int main(int argc, char **argv)
{
 if (argc==1)
 {
  fptus("need an argument/n", stderr);
  return 1;
 }

 while (--argc)
 {
  char *end;
  long num = strtol(*++argv, &end, 16);
  if (*end)
  {
   /* you could also add errno checking */
   fprintf(stderr, "%s: invalid number/n", *argv);
  }
  else
  {
   printf("%d/n", num);
  }
 } 
 return 0;
}

///
//eg7. One way is using stringstreams:
///

#include <iostream>
#include <cstdlib>
#include <string>
#include <sstream>

std::string hex2DecString(std::string hexStr)
{
 std::stringstream ss;

 // Read hexadecimal number into stream
 if (!(ss << std::hex << hexStr))
 {
  throw "hex2DecString: Conversion 1 error.";
 }

 // Read integer from stream
 int intVal;
 if (!(ss >intVal))
 {
  throw "hex2DecString: Conversion 2 error.";
 }

 // Read integer back into stream as decimal
 ss.clear(); // **See note below**
 ss.str("");
 if (!(ss << std::dec << intVal))
 {
  throw "hex2DecString: Conversion 3 error.";
 }

 // Extract decimal string of number
 return ss.str();
}

int main()
{
 std::string hexStr = "1AB";
 std::string decStr = hex2DecString(hexStr);
 std::cout << "Hex = " << hexStr << "/tDecimal = " << decStr << std::endl;
 return EXIT_SUCCESS;
}

 

Table of ASCII Characters
http://web.cs.mun.ca/~michael/c/ascii-table.html