基础工程

---basictype.h---

#ifndef __BASICTYPE_H__
#define __BASICTYPE_H__

typedef unsigned char  uchar;
typedef   signed char  schar;
typedef unsigned short ushort;
typedef   signed short sshort;
typedef unsigned int   uint;
typedef   signed int   sint;
typedef unsigned long  ulong;
typedef   signed long  slong;

typedef unsigned char  uint8;
typedef   signed char  sint8;
typedef unsigned short uint16;
typedef   signed short sint16;
typedef unsigned int   uint32;
typedef   signed int   sint32;
typedef unsigned long  ulong32;
typedef   signed long  slong32;

typedef unsigned char  uint8_t;
typedef   signed char  sint8_t;
typedef unsigned short uint16_t;
typedef   signed short sint16_t;
typedef unsigned int   uint32_t;
typedef   signed int   sint32_t;
typedef unsigned long  ulong32_t;
typedef   signed long  slong32_t;

#endif

---char2hex.h---

#ifndef __CHAR2HEX_H__
#define __CHAR2HEX_H__

#include "basictype.h"

#define IS_HEX_CHAR(x) ((((x)>='0')&&((x)<='9'))||(((x)>='a')&&((x)<='f'))||(((x)>='A')&&((x)<='F')))

#define CHAR2HEX(x) ((((x)>='0')&&((x)<='9'))?((x)-'0'):(((x)>='a')&&((x)<='f'))?((x)-'a'+10):((x)-'A'+10))

bool is_hex_char(char x);

bool char2hex(char x, int* v);

bool char2num(char x, int* v);

int hex_char_str_to_byte_stream(const char* p, uchar* buf, uint n);

uint get_uint_value_from_hex_char_str(const char* p);

uint get_uint_value_from_char_str(const char* p);

#endif

---char2hex.cpp---

#include "char2hex.h"

#ifndef NULL
#define NULL ((void*)0)
#endif

bool is_hex_char(char x)
{
    if (x >= '0' && x <= '9') {
        return true;
    }
    if (x >= 'a' && x <= 'f') {
        return true;
    }
    if (x >= 'A' && x <= 'F') {
        return true;
    }
    return false;
}

bool char2hex(char x, int *v)
{
    if (v == NULL) {
        return false;
    }
    if (x >= '0' && x <= '9') {
        *v = x - '0';
        return true;
    }
    if (x >= 'a' && x <= 'f') {
        *v = x - 'a' + 10;
        return true;
    }
    if (x >= 'A' && x <= 'F') {
        *v = x - 'A' + 10;
        return true;
    }
    return false;
}

bool char2num(char x, int* v)
{
    if (v == NULL) {
        return false;
    }
    if (x >= '0' && x <= '9') {
        *v = x - '0';
        return true;
    }
    return false;
}

/*
 * p is a pointer point to string such like "12 34 56 78 9A BC DE F0" 
 * buf is a array to store convert result
 * n is the buf size
 * the return value is real convert size
 * in this example the convert size may be equal to 8 while n >= 8, if n < 8, the convert size is n
 */
int hex_char_str_to_byte_stream(const char* p, uchar* buf, uint n)
{
    int i = 0;
    uchar hex = 0;
    int tmp1;
    int tmp2;
    //check par
    if (p == NULL || buf == NULL || n == 0) {
        return 0;
    }
    while (1) {
        if (char2hex(*p, &tmp1)) {
            p++;
            if (char2hex(*p, &tmp2)) {
                p++;
                if (*p == ' ') {
                    p++;
                }
                hex = (tmp1 << 4) | tmp2;
                buf[i++] = hex;
                if (i >= n) {
                    return n;
                }
                if (*p == 0) {
                    return i;
                }
            }
            else {
                return 0;
            }
        }
        else {
            return 0;
        }
    }

}

uint get_uint_value_from_hex_char_str(const char* p)
{
    uint ret = 0;

    if (p == NULL) {
        return 0;
    }

    if (*p == '0' && (*(p+1)) == 'x') {
        p += 2;
    }
    else if (*p == '0' && (*(p+1)) == 'X') {
        p += 2;
    }

    int tmp;
    while (char2hex(*p, &tmp)) {
        ret = (ret << 4) + tmp;
        p++;
    }

    return ret;
}

uint get_uint_value_from_char_str(const char* p)
{
    uint ret = 0;
    uint base = 10;

    if (p == NULL) {
        return 0;
    }

    if (*p == '0' && (*(p + 1)) == 'x') {
        p += 2;
        base = 16;
    }
    else if (*p == '0' && (*(p + 1)) == 'X') {
        p += 2;
        base = 16;
    }

    int tmp;
    if (base == 16) {
        while (char2hex(*p, &tmp)) {
            ret = ret * base + tmp;
            p++;
        }
    }
    else {
        while (char2num(*p, &tmp)) {
            ret = ret * base + tmp;
            p++;
        }
    }

    return ret;
}