C++ implements an example of reading a configuration file to memory line by line
- 2020-04-02 02:22:11
- OfStack
Do not parse the configuration content, just read the file content, cut out the comments and Spaces before writing cache: vector
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The string
>
In the. For other methods.
The code was written while making an MFC widget.
ReadProtocol. H
#pragma once
#include <vector>
#include <map>
#include <list>
#include <string>
using namespace std;
#define MAX_FILEPATH 512
#define COMMENT_FLG '#'
#define SECTION_BEGIN_FLG '['
#define SECTION_END_FLG ']'
class ReadProtocol {
public:
ReadProtocol(char* FilePath);
~ReadProtocol();
char* GetErrInfo(char* errMsg, int errNo = 0);
int ReadIniFile();
int GetOneSection(string Section, list<string> &Protocol);
private:
void PushBackToVector(string oneLine);
private:
char m_IniFile[MAX_FILEPATH];
string m_ErrPos;
map<string, unsigned int> m_SectionMap;
vector<string> m_StrVect;
};
ReadProtocol. CPP
//
//#include "stdafx.h"
#include <fstream>
#include "ReadProtocol.h"
//Remove Spaces at the beginning and end of a string
static string strTrim(string aStr)
{
string s = aStr;
unsigned int first, last;
if (string::npos != (first = s.find_first_not_of(' ') ))
s = s.substr(first, s.length()-first);
if (string::npos != (last = s.find_last_not_of(' ') ))
s = s.substr(0, last+1);
return s;
}
///=====================================================================================
ReadProtocol::ReadProtocol(char* FilePath)
{
int iLen = (strlen(FilePath) > MAX_FILEPATH) ? MAX_FILEPATH : strlen(FilePath);
memset(m_IniFile, 0, MAX_FILEPATH);
memcpy(m_IniFile, FilePath, iLen);
}
ReadProtocol::~ReadProtocol()
{
m_SectionMap.clear();
m_StrVect.clear();
}
int ReadProtocol::GetOneSection(string Section, list<string> &Protocol)
{
unsigned int Start = 0;
//Note that the [] operator cannot be used here
map<string, unsigned int>::iterator itr = m_SectionMap.find(Section);
if (m_SectionMap.end() == itr)
{
m_ErrPos = Section;
return -5; // Unknown Section!!
}
else
{
Start = itr->second;
}
vector<string>::iterator it = m_StrVect.begin() + Start + 1;
for (; it!=m_StrVect.end(); ++it)
{
unsigned int First, Last;
First = it->find_first_of ( SECTION_BEGIN_FLG );
Last = it->find_last_of ( SECTION_END_FLG );
// stop when the next Section
if( string::npos != First && string::npos != Last)
{
break;
}
Protocol.push_back(*it);
}
return (int)Protocol.size();
}
int ReadProtocol::ReadIniFile()
{
ifstream fin(m_IniFile);
if (!fin.is_open())
{
return -1; //can'topen file
}
string strLine;
unsigned int Last;
while (std::getline(fin, strLine).good())
{
if ( string::npos !=(Last = strLine.find_last_not_of('r') ))
{
//delete r
strLine = strLine.substr(0, Last + 1);
}
PushBackToVector(strLine);
}
fin.close();
if (m_StrVect.empty())
{
return -2; //get noting from file
}
return 0;
}
void ReadProtocol::PushBackToVector(string oneLine)
{
unsigned int uPos;
//Remove end-of-line comments
if ( string::npos != (uPos = oneLine.find_first_of( COMMENT_FLG ) ) )
{
oneLine = oneLine.substr(0, uPos + 1);
}
//Go to Spaces
oneLine = strTrim(oneLine);
if (oneLine.empty() || oneLine.length() < 2) return;
//There can be only one record in a row
unsigned int First, Last;
First = oneLine.find_first_of(SECTION_BEGIN_FLG);
Last = oneLine.find_last_of(SECTION_END_FLG);
// is Section
if( string::npos != First && string::npos != Last)
{
m_SectionMap[ oneLine.substr(First + 1, Last - First - 1) ] = m_StrVect.size();
}
m_StrVect.push_back(oneLine);
}
char* ReadProtocol::GetErrInfo(char* errMsg, int errNo)
{
string errInfo;
switch (errNo)
{
case 0:
{
errInfo = "Success!";
break;
}
case -1:
{
char Path[1024] = {0};
int pLength = 1024;
GetCurrentDirectory(pLength, Path);
errInfo.append("Can't open file. The file name is:==>"");
errInfo.append( m_IniFile);
errInfo.append(""rnMaybe no such file in Path:");
errInfo.append(Path);
break;
}
case -2:
{
errInfo = "Get noting from file: ";
errInfo.append(m_IniFile);
break;
}
case -3:
{
errInfo = "Analyze file failed. In ==> ";
errInfo.append(m_ErrPos);
break;
}
case -5:
{
errInfo = "rnUnknown Section!! ==> "[";
errInfo.append(m_ErrPos);
errInfo.append("]"rn Check the configuration file for omissions. ");
break;
}
default:
{
errInfo = " Please follow the correct steps ";
}
}
memcpy(errMsg, errInfo.c_str(), errInfo.length());
return errMsg;
}