Linux 下读XML 的类

Linux下XML解析器实现

最新推荐文章于 2025-06-05 16:03:50 发布

原创最新推荐文章于 2025-06-05 16:03:50 发布 · 2.7k 阅读

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#xml #linux #null #buffer #delete #encoding

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本文介绍了一种在Linux环境下自行实现的XML解析器，该解析器能够处理基本的XML文件结构，包括元素、属性及层级关系。通过示例代码展示了如何解析XML文件并获取所需数据。

在Linux下写程序，常需要读一些配置文件。现有的XML工具很多，可以方便的编辑和生成XML。

但VC中用的XML解析器在Linux下不能用。只好自已写了个。用了一下，还不错。

#include <stdio.h>
#include <stdlib.h>

// ********************************************************************** //
// XML解析类(honghaier写于2008-11-19)
// ********************************************************************** //

struct SXMLAttrib
{
char mKeyName[100]; //键名
char mValue[100]; //键值
}
;

struct SXMLFrame
{
public:
char  mFrameName[100]; //帧名
int   mAttrNum;   //属性数量
SXMLAttrib* mAttrArray;   //属性数组

SXMLFrame* mpSiblFrame;  //兄弟结点
SXMLFrame* mpChiFrame;   //子结点
SXMLFrame* mpParentFrame;  //父结点
public:

SXMLFrame();
~SXMLFrame();

void Release_Depath();

SXMLFrame* GetFrame_Depth(char *szFrameName);

int GetChildNum();
SXMLFrame* GetChildFrame(int Index);
SXMLFrame* GetChildFrame(char *szFrameName);
SXMLFrame* GetSiblFrame();
SXMLFrame* GetParentFrame();
SXMLAttrib* GetAttrib(char *szKeyName);

bool ParseAttrString(char *szXMLString);
}
;
class CXMLFile
{
SXMLFrame mRoot;
SXMLFrame* mpCurrentFrame;
bool mbDepthClose; //闭合
private:
bool ParseFrameString(char *szXMLString);

public:
int pFile;

CXMLFile();
~CXMLFile();
void Close();
void Release();
bool Open( const char * pFileName);

SXMLFrame* GetRoot();
SXMLFrame* GetFrame_Depth(char *szFrameName);

}
;

//====================================================

SXMLFrame::SXMLFrame()
{
memset(mFrameName,0,sizeof(mFrameName));
mAttrNum = 0;
mAttrArray = NULL;
mpSiblFrame = NULL;
mpChiFrame = NULL;
mpParentFrame = NULL;
}
SXMLFrame::~SXMLFrame()
{
Release_Depath();
}

void SXMLFrame::Release_Depath()
{
if(mAttrNum > 0)
{
  if(mAttrArray)
  {
   delete[] mAttrArray;
   mAttrArray = NULL;
  }
  mAttrNum = 0;
}
if(mpChiFrame)
{
  mpChiFrame->Release_Depath();
  delete mpChiFrame;
  mpChiFrame = NULL;
}
if(mpSiblFrame)
{
  mpSiblFrame->Release_Depath();
  delete mpSiblFrame;
  mpSiblFrame = NULL;
}
}

SXMLFrame* SXMLFrame::GetFrame_Depth(char *szFrameName)
{
if(strcmp(mFrameName,szFrameName)==0)
{
  return this;
}
if(mpChiFrame)
{
  SXMLFrame* tResFrame = mpChiFrame->GetFrame_Depth(szFrameName);
  if(tResFrame)return tResFrame;
}
if(mpSiblFrame)
{
  SXMLFrame* tResFrame = mpSiblFrame->GetFrame_Depth(szFrameName);
  if(tResFrame)return tResFrame;
}

return NULL;
}
int SXMLFrame::GetChildNum()
{
int count = 0;
for(SXMLFrame *temp = mpChiFrame ; temp != NULL ;temp = temp->mpSiblFrame)
{
count++;
}
return count;
}

SXMLFrame* SXMLFrame::GetChildFrame(int Index)
{
int count = 0;
for(SXMLFrame *temp = mpChiFrame ; temp != NULL ;temp = temp->mpSiblFrame)
{
if(count == Index)return temp;
count++;
}
return NULL;
}

SXMLFrame* SXMLFrame::GetChildFrame(char *szFrameName)
{
for(SXMLFrame *temp = mpChiFrame ; temp != NULL ;temp = temp->mpSiblFrame)
{
  if(strcmp(temp->mFrameName,szFrameName)==0)
  {
   return temp;
  }
}
return NULL;
}

SXMLFrame* SXMLFrame::GetSiblFrame()
{
return mpSiblFrame;
}

SXMLFrame* SXMLFrame::GetParentFrame()
{
return mpParentFrame;
}

SXMLAttrib* SXMLFrame::GetAttrib(char *szKeyName)
{
for(int i = 0 ; i < mAttrNum ; i++)
{
  if(strcmp(mAttrArray[i].mKeyName,szKeyName)==0)
  {
   return &mAttrArray[i];
  }
}
return NULL;
}

bool SXMLFrame::ParseAttrString(char *szXMLString)
{
SXMLAttrib AttribArray[100];
int len = strlen(szXMLString);
mAttrNum = 0;
int StrPos = 0;
bool HaveFrameName = false;
for(int i = 0 ;i < len ; i++)
{
  if(i==(len-1))
  {
   if(false == HaveFrameName)
   {
    memcpy(mFrameName,szXMLString,len);
    mFrameName[len]='/0';
    HaveFrameName = true;
   }
   else
   {
    if(( len - StrPos-1 )== 0)
    {
     memset(AttribArray[mAttrNum].mValue,0,sizeof(AttribArray[mAttrNum].mValue));
    }
    else
    {
     memcpy(AttribArray[mAttrNum].mValue,szXMLString+StrPos,len-StrPos-1);
     AttribArray[mAttrNum].mValue[len-StrPos-1]='/0';
    }
    mAttrNum++;
    StrPos = 0;
   }
   break;
  }
  if(szXMLString[i] == ' '&&szXMLString[i-1] == ' ')
  {
   StrPos = i+1;
   continue;
  }
  if(szXMLString[i] == ' ')
  {
   if(false == HaveFrameName)
   {
    memcpy(mFrameName,szXMLString,i);
    mFrameName[i]='/0';
    HaveFrameName = true;
    StrPos = i+1;
    continue;
   }
   else
   {
    if(( i - StrPos-1 )== 0)
    {
     memset(AttribArray[mAttrNum].mValue,0,sizeof(AttribArray[mAttrNum].mValue));
    }
    else
    {
     memcpy(AttribArray[mAttrNum].mValue,szXMLString+StrPos,i-StrPos-1);
     AttribArray[mAttrNum].mValue[i-StrPos-1]='/0';
    }
    mAttrNum++;
    StrPos = i+1;
    continue;
   }
  }

  if(szXMLString[i] == '=')
  {
   memcpy(AttribArray[mAttrNum].mKeyName,szXMLString+StrPos,i-StrPos);
   AttribArray[mAttrNum].mKeyName[i-StrPos]='/0';
   i++;//跳过一个"""
   StrPos = i+1;
   continue;
  }

}

mAttrArray = new SXMLAttrib[mAttrNum];
if(!mAttrArray)return false;
memcpy(mAttrArray,AttribArray,mAttrNum*sizeof(SXMLAttrib));
return true;
}

CXMLFile::CXMLFile()
{
pFile = 0;
mpCurrentFrame = NULL;
mbDepthClose = false;
}

CXMLFile::~CXMLFile()
{
Close();
}

void CXMLFile::Close()
{
if( pFile>0)
{
  int error = close( pFile);
  if( error!=0)
  {
   perror("close file failed");
  }else
  {
   pFile=-1;
  }
  Release();
}
}
void CXMLFile::Release()
{
mRoot.Release_Depath();
}

bool CXMLFile::Open( const char * pFileName)
{
pFile =0;
pFile = open( pFileName,O_RDONLY);
if( pFile==-1)
{
perror(pFileName);
return false;
}

int num = 0;
char buffer;

bool bReadXMLString = false;
int XMLStringNum = 0;
char XMLString[1024];
while(num = read(pFile,&buffer,1)>0)
{
  if(buffer =='<')
  {
   bReadXMLString = true;
   XMLStringNum = 0;
   continue;
  }
  if(buffer == '>')
  {
   XMLString[XMLStringNum]='/0';
   if( false == ParseFrameString(XMLString))
   {
    printf("Read XML error: %s /n",XMLString);
    return false;
   }

   bReadXMLString = false;

   continue;
  }
  if(true == bReadXMLString)
  {
   XMLString[XMLStringNum++] = buffer;
  }

}

mpCurrentFrame = NULL;
mbDepthClose = true;
return true;
}

SXMLFrame* CXMLFile::GetRoot()
{
return &mRoot;
}

SXMLFrame* CXMLFile::GetFrame_Depth(char *szFrameName)
{
return mRoot.GetFrame_Depth(szFrameName);
}

bool CXMLFile::ParseFrameString(char *szXMLString)
{
if(szXMLString[0] == '?')return true;
if(szXMLString[0] == '!')return true;

if(szXMLString[0] == '/')
{
  //如果是结束
  mpCurrentFrame = mpCurrentFrame->GetParentFrame();
  mbDepthClose = true;
}
else
{
  mbDepthClose = false;

  if( NULL == mpCurrentFrame)
  {
   mpCurrentFrame = &mRoot;
  }

  SXMLFrame* tNewFrame = new SXMLFrame;
  tNewFrame->ParseAttrString(szXMLString);

  if(false == mbDepthClose)
  {
   tNewFrame->mpParentFrame = mpCurrentFrame;
   if( NULL == mpCurrentFrame->mpChiFrame)
   {
    mpCurrentFrame->mpChiFrame = tNewFrame;
   }
   else
   {
    for(SXMLFrame *temp = mpCurrentFrame->mpChiFrame ; temp != NULL ;temp = temp->mpSiblFrame)
    {
     if( NULL == temp->mpSiblFrame)
     {
      temp->mpSiblFrame = tNewFrame;
      break;
     }
    }
   }
   mpCurrentFrame = tNewFrame;
  }
  else
  {
   tNewFrame->mpParentFrame = mpCurrentFrame->GetParentFrame();
   mpCurrentFrame->mpSiblFrame = tNewFrame;

mpCurrentFrame = tNewFrame;
}

}

return true;
}

用XML工具做了一个简单的XML文件。

<?xml version="1.0" encoding="UTF-8"?>

<root>
<Honghaier Name="红孩儿" Age="26"></Honghaier>
</root>

========================================================

在C++代码中

可以这样使用

CXMLFile xmlfile;

xmlfile.Open("1.xml");

SXMLFrame* mRootFrame = CXMLFile::GetRoot();

int ChildNum = mRootFrame ->GetChildNum();

for(int i = 0 ; i < ChildNum ; i++)

{

SXMLFrame* tChileFrame = mRootFrame ->GetChildFrame (i);

SXMLAttrib* tAttrib = tChileFrame->GetAttrib("Age");

print("%s : %s= %s /n",mChileFrame ->mFrameName,tAttrib->mKeyName,tAttrib->mValue);