xml逸出字元轉換

//
#include <stdio.h>
#include <string.h>

#define MAXLEN_OF_SM_CONTENT 200

char uniTempStr[1024];
/*   five chars have transferred meaning in XML document
&lt;             < 
&gt;             > 
&   &       
'   '       
"    "
*/
char* txt_to_xml(const char* content, int length)
{
        const char *cursor=content;
        const char *end=content+((length>MAXLEN_OF_SM_CONTENT)?MAXLEN_OF_SM_CONTENT:length);
        char *newcontent=uniTempStr;
        char* pnew=newcontent;
        int len=MAXLEN_OF_SM_CONTENT;

//        memset(newcontent,'/0',MAXLEN_OF_SM_CONTENT+1);
        while ((cursor<end)&&(len>0))
        {
          switch(*cursor)
          {
                case '<':        
                        if (len>=4)
                        {memcpy(pnew,"&lt;",4); pnew+=4; cursor++; len-=4;}
                        else
                                len=0;
                        break;
                case '>':        
                        if (len>=4)
                        {memcpy(pnew,"&gt;",4); pnew+=4; cursor++; len-=4;}
                        else
                                len=0;
                        break;
                case '&':
                        if (len>=5)
                        {memcpy(pnew,"&amp;",5); pnew+=5; cursor++; len-=5;}
                        else
                                len=0;
                        break;
                case '/'':
                        if (len>=6)
                        {memcpy(pnew,"&apos;",6); pnew+=6; cursor++; len-=6;}
                        else
                                len=0;
                        break;
                case '"':
                        if (len>=6)
                        {memcpy(pnew,"&quot;",6); pnew+=6; cursor++; len-=6;}
                        else
                                len=0;
                        break;
                default: { *pnew++=*cursor++;        len-=1;}
                        break;
                       
          }
//          printf("%c len:%d/r/ncontent:%s/r/n",*(cursor-1),len,newcontent);
//          printf("pnew-newcontent=%d/n",pnew-newcontent);
        }
//         printf("pnew-newcontent=%d/n",pnew-newcontent);
//         printf("content:%s/n",newcontent);
        *pnew='/0';

        return newcontent;

}

char* xml_to_txt(const char* content, int length)
{
        const char *cursor=content;
        const char *end=content+((length>MAXLEN_OF_SM_CONTENT)?MAXLEN_OF_SM_CONTENT:length);
        char *newcontent=uniTempStr;
        char* pnew=newcontent;

        while (cursor<end)
        {
                if ('&'==*cursor)
                {
                        if (0==strncmp(cursor,"&lt;",4))
                                {*pnew++='<'; cursor+=4;}
                        else if (0==strncmp(cursor,"&gt;",4))
                                {*pnew++='>'; cursor+=4;}
                        else if (0==strncmp(cursor,"&amp;",5))
                                {*pnew++='&'; cursor+=5;}
                        else if (0==strncmp(cursor,"&apos;",6))
                                {*pnew++='/''; cursor+=6;}
                        else if (0==strncmp(cursor,"&quot;",6))
                                 {*pnew++='"'; cursor+=6;}
                        else
                                {*pnew++='.'; cursor++;}
                }
                else
                        {*pnew++=*cursor++;}
        }
        *pnew='/0';

        return newcontent;
}

int main(int argc, char** argv)
{
//         if (argc<2)
//                 return 0;

 char *pstr = "sdfsd;f/"<1234>&678";
 printf("%s/n",pstr);
 char *pstr2 = txt_to_xml(pstr,strlen(pstr));
 printf("%s/n",pstr2);

  printf("%s/n",xml_to_txt(pstr2,strlen(pstr2)));    
         
  getchar();
     
}