需要解析一种类xml的数据文件，数据格式1如下：
<head> //文件头
<type>xtype</type>
<condition>
key1=value1
key2=value2
</condition>
<mea>
key3=value3
key4=value4
</mea>
<xxxx>//多个
...
</xxx>
</head>
<data> //数据域，多个
phi rcs ang </data>
<data>
phi rcs ang </data>
数据格式2：
#xtype
//comment
[condition]
项1=值1
项2=值2
[/condition]
[mea]
key3=value3
key4=value4
[/mea]
[data]
phi rcs ang [/data]
[data]
phi rcs ang [/data]
该数据格式类似xml，我们需要解析的是head中的所有标签，及标签中的键值对（key=value），并将data域中的数据保存成浮点型数组。
采用类似xml的解析方式，递归进行解析
具体代码如下：
#ifndef MYPARSEGJBDATA_H_20170114
#define MYPARSEGJBDATA_H_20170114 #include <string>
#include <map>
#include <vector>
#include <iostream>
#include <fstream>
#include <sstream>
using namespace std; /*file format1:
<head>
<type>xtype</type>
<conditon>
key1=value1
key2=value2
</condition>
<mea>
key3=value3
key4=value4
</mea>
</head>
<data>
phi rcs ang
1 1 1
2 2 2
</data>
*/ typedef struct stMyDataLabel{
string Label;//标签名称
vector<string> Content;//对于<lable>content</label>的形式，纯字符串，非键值对
vector<float> Values;//对应数据域，一维数组表示二维数组；数组的列数为Contens'size
map<string,string> KeyVal;//<label>内的键值对
vector<stMyDataLabel> SubItems;//子节点列表 stMyDataLabel(){
Label = "";
Content.clear();
Values.clear();
KeyVal.clear();
SubItems.clear();
}
void Clear(){//递归清空内存
for (vector<stMyDataLabel>::iterator itr = SubItems.begin();itr!=SubItems.end();itr++)
{
itr->Clear();
}
Content.clear();
Values.clear();
KeyVal.clear();
SubItems.clear();
} friend ostream& operator <<(ostream& myout,stMyDataLabel& m_Data){//输出流
myout<<m_Data.Label<<endl;
for (vector<string>::iterator sitr = m_Data.Content.begin(); sitr != m_Data.Content.end(); sitr++)
{
myout<<"\t"<<*sitr<<"\t";
}
myout<<endl;
for (auto mitr = m_Data.KeyVal.begin(); mitr != m_Data.KeyVal.end(); mitr++)
{
myout<<"\t"<<mitr->first<<" = "<<mitr->second<<"\t";
}
myout<<endl; int dsize = m_Data.Content.size();
int curdidx = ;
for(vector<float>::iterator fitr = m_Data.Values.begin(); fitr != m_Data.Values.end(); fitr++){
myout<<"\t"<<*fitr<<"\t";
curdidx++;
if(curdidx >= dsize){
cout<<endl;
curdidx=;
}
}
myout<<endl;
for (vector<stMyDataLabel>::iterator itr = m_Data.SubItems.begin();itr != m_Data.SubItems.end(); itr++)
{
myout<<*itr<<endl;
}
return myout;
}
}stMyDataLabel; class MyDataParse{//数据类型1的解析类
public:
vector<stMyDataLabel> m_Data;
stMyDataLabel m_Header;
char m_StartLabel;
char m_EndLabel;
public:
MyDataParse(){
m_StartLabel = '<';
m_EndLabel = '>';
}
void Init(){
m_Header.Clear();
for (vector<stMyDataLabel>::iterator itr = m_Data.begin();itr!=m_Data.end();itr++)
{
itr->Clear();
}
} void Print(ostream& myout){
myout<<m_Header<<endl;
for (vector<stMyDataLabel>::iterator ditr = m_Data.begin();ditr!=m_Data.end();ditr++)
myout<<*ditr<<endl;
} bool Parse(char* filename){
if(filename == NULL) return false;
ifstream myin(filename,ios::in);
bool flag = ParseLabel(myin,m_Header);
if(!flag) return false;
while(!myin.eof()){
stMyDataLabel data;
flag = ParseLabel(myin,data);
m_Data.push_back(data);
}
return flag;
} bool ParseLabel(istream& myin,stMyDataLabel& label){
string str;
bool flag = true;
do{
myin >> str;
int sidx=,eidx=;
sidx = str.find(m_StartLabel);
eidx = str.find(m_EndLabel);
if(sidx >= && eidx >= && eidx > sidx){//<lable> or </label>
if(str.at(sidx+) != '/')//start of <label>
{
//string substr(int pos = 0,int n = npos) const;//返回pos开始的n个字符组成的字符串
bool isSub=false;
string lableName = str.substr(sidx+,eidx-sidx-);
if(label.Label != "") isSub = true;//start of subitem's <label> //find </label>
int sidx2=,eidx2=;
sidx2 = str.rfind(m_StartLabel);
eidx2 = str.rfind(m_EndLabel);
if(eidx != eidx2 && str.at(sidx2+) == '/')//<label>content</label>, has </label>
{
string strelab = str.substr(sidx2+,eidx2-sidx2-);
if(strelab == lableName){
if(isSub){
stMyDataLabel sublabel;
sublabel.Label = lableName;
sublabel.Content.clear();
sublabel.Content.push_back( str.substr(eidx+,sidx2-eidx-) );
label.SubItems.push_back(sublabel);
}
else{
label.Label = lableName;
label.Content.clear();
label.Content.push_back( str.substr(eidx+,sidx2-eidx-) );
}
continue;
}
else{
return false;
}
}
else{
if(isSub){
stMyDataLabel sublabel;
sublabel.Label = lableName;
label.SubItems.push_back(sublabel);
int curIdx = label.SubItems.size()-;
bool bres = ParseLabel(myin,label.SubItems.at(curIdx));
if(!bres) return false;//subitem format error
else continue;//
}
else
label.Label = lableName;
}
}
else{// </lable>
string elabel = str.substr(sidx+,eidx-sidx-);
if(elabel == label.Label){//end of this label
return true;
}
else{//format error
return false;
}
}
}
else{//content
if(label.Label == "data" || label.Label == "DATA"){//data block
// 判断字符串是不是数字
stringstream sin(str);
float val;
if(!(sin >> val))//不是数字
label.Content.push_back(str);
else
label.Values.push_back(val);
}
else//header
{
int idx = str.find('=');
if(idx >= ){//key=value
string strkey = str.substr(,idx);
string strval = str.substr(idx+);
label.KeyVal.insert(make_pair(strkey,strval));
}
else{
label.Content.push_back(str);
}
}
}
}while(flag);
}
// 判断字符串是不是数字
bool isNum(string str)
{
stringstream sin(str);
double d;
char c;
if(!(sin >> d))
return false;
if (sin >> c)
return false;
return true;
}
}; /*file format2:
#xtype
//comment
[condition]
项1=值1
项2=值2
[/condition]
[mea]
key3=value3
key4=value4
[/mea]
[data]
phi rcs ang
1 1 1
2 2 2
[/data]
*/
class MyDataParse2{//数据类型2的解析类
public:
stMyDataLabel m_Data;//single root
char m_StartLabel;
char m_EndLabel;
public:
MyDataParse2(){
m_StartLabel = '[';
m_EndLabel = ']';
}
void Init(){
m_Data.Clear();
} void Print(ostream& myout){
myout<<m_Data;
} bool Parse(char* filename){
if(filename == NULL) return false;
ifstream myin(filename,ios::in);
string str;
myin>>str;
if(str.at() == '#'){
m_Data.Label = str.substr();
}
bool flag = true;
while(!myin.eof() && flag){
flag = ParseLabel(myin,m_Data);
}
return flag;
} bool ParseLabel(istream& myin,stMyDataLabel& label){
string str;
bool flag = true;
do{
myin >> str;
if(str.substr(,) == "//")//comment,skip
continue; int sidx=,eidx=;
sidx = str.find(m_StartLabel);
eidx = str.find(m_EndLabel);
if(sidx >= && eidx >= && eidx > sidx){//[lable] or [/label]
if(str.at(sidx+) != '/')//start of <label>
{
//string substr(int pos = 0,int n = npos) const;//返回pos开始的n个字符组成的字符串
bool isSub=false;
string lableName = str.substr(sidx+,eidx-sidx-);
if(label.Label != "") isSub = true;//start of subitem's [label] if(isSub){
stMyDataLabel sublabel;
sublabel.Label = lableName;
label.SubItems.push_back(sublabel);
int curIdx = label.SubItems.size()-;
bool bres = ParseLabel(myin,label.SubItems.at(curIdx));
if(!bres) return false;//subitem format error
else continue;//
}
else
label.Label = lableName;
}
else{// </lable>
string elabel = str.substr(sidx+,eidx-sidx-);
if(elabel == label.Label){//end of this label
return true;
}
else{//format error
return false;
}
}
}
else{//content
if(label.Label == "data" || label.Label == "DATA"){//data block
// 判断字符串是不是数字
stringstream sin(str);
float val;
if(!(sin >> val))//不是数字
label.Content.push_back(str);
else
label.Values.push_back(val);
}
else//header
{
int idx = str.find('=');
if(idx >= ){//key=value
string strkey = str.substr(,idx);
string strval = str.substr(idx+);
label.KeyVal.insert(make_pair(strkey,strval));
}
else{
label.Content.push_back(str);
}
}
}
}while(!myin.eof());
}
};
#endif
测试（命令行方式）
MyDataParse parse;
parse.Init();
parse.Parse("test.txt");//待解析的数据文件
parse.Print(cout);
测试数据：
//test11.txt
<head>
<type>xtype</type>
<condition>
key1=value1
key2=value2
</condition>
<mea>
key3=value3
key4=value4
</mea>
</head>
<data>
phi rcs ang </data>
<data>
phi rcs ang </data>
//test12.txt
<head>
<type>xtype</type>
<condition>
key1=value1
key2=value2
</condition>
<group>
<part1>
key3=value3
key4=value4
</part1>
<part2>
key3=value3
key4=value4
</part2>
</group>
</head>
<data>
phi rcs ang </data>
<data>
phi rcs ang </data>
//test21.txt
#xtype
//comment
[condition]
项1=值1
项2=值2
[/condition]
[mea]
key3=value3
key4=value4
[/mea]
[data]
phi rcs ang [/data]
[data]
phi rcs ang [/data]
//test22.txt
#xtype
//comment
[condition]
项1=值1
项2=值2
[/condition]
[group]
[part1]
key3=value3
[/part1]
[part2]
key4=value4
key5=value5
[/part2]
[/group]
[data]
phi rcs ang [/data]
[data]
phi rcs ang [/data]