c++ 利用boost 实现文件操作

对文件夹里面的文件进行遍历操作是基本技能之一，python，perl以及bash等脚本都很好的实现了文件遍历方法，对于c/c++来说，只能通过系统自定的api获取。虽然文件夹操作本身是调用操作系统内核的接口，但毕竟接口不够友好。

boost不愧是准标准库，filesystem提供了极为简便的方法，如下所示:

[cpp] view plain copy
//  filesystem tut3.cpp  ---------------------------------------------------------------//

//  Copyright Beman Dawes 2009

//  Distributed under the Boost Software License, Version 1.0.
//  See http://www.boost.org/LICENSE_1_0.txt 
//  Library home page: http://www.boost.org/libs/filesystem 
#include <iostream>
#include <iterator>
#include <algorithm>
#include <boost/filesystem.hpp>
using namespace std;
using namespace boost::filesystem;

int main(int argc, char* argv[])
{
if (argc < 2)
{
cout << "Usage: tut3 path\n";
return 1;
}

path p (argv[1]);   // p reads clearer than argv[1] in the following code

try
{
if (exists(p))    // does p actually exist?
{
if (is_regular_file(p))        // is p a regular file?
cout << p << " size is " << file_size(p) << '\n';

else if (is_directory(p))      // is p a directory?
{
cout << p << " is a directory containing:\n";

copy(directory_iterator(p), directory_iterator(),  // directory_iterator::value_type
ostream_iterator<directory_entry>(cout, "\n"));  // is directory_entry, which is
// converted to a path by the
// path stream inserter
}
else
cout << p << " exists, but is neither a regular file nor a directory\n";
}
else
cout << p << " does not exist\n";
}

catch (const filesystem_error& ex)
{
cout << ex.what() << '\n';
}

return 0;
}

然而，每次写程序都要附上如此一大篇代码，很不美观。故作了简单封装。

.h文件

[cpp] view plain copy
#ifndef DIRFILEOPT_HHHH
#define DIRFILEOPT_HHHH

#include <iostream>
#include <vector>
#include <string>

using std::vector;
using std::string;

class CFileOpt
{
private:
bool m_bIsDir;
bool m_bIsFile;
char* m_pFileName;
bool mDirOrFile();

public:
CFileOpt(char*);
vector<string>& mGetSubFiles(vector<string>& lstpFileNames);
~CFileOpt();
};#endif

.cpp文件

[cpp] view plain copy
#define _SCL_SECURE_NO_WARNINGS
#include "FileOpt.h"
#include <iterator>
#include <algorithm>
#include <boost/filesystem.hpp>
#include <boost/algorithm/string/classification.hpp>
#include <boost/algorithm/string.hpp>
using namespace std;
using namespace boost::filesystem;

bool CFileOpt::mDirOrFile()
{
if(NULL == m_pFileName)
return false;
path p(m_pFileName);
try{
if(exists(p)){
if (is_regular_file(p))
m_bIsFile = true;
else if (is_directory(p)){
m_bIsDir = true;
}
}else{
return false;
}
}catch (const filesystem_error& ex){
#ifdef DEBUG
printf(ex.what());
#endif
}
return true;
}
CFileOpt::CFileOpt(char* pfilename):
m_pFileName(pfilename),m_bIsDir(false),m_bIsFile(false){
mDirOrFile();
}
vector<string>& CFileOpt::mGetSubFiles(vector<string>& lstpFileNames)
{
if(m_bIsDir){
path p(m_pFileName);
typedef vector<path> vec;             // store paths,
vec pathes;
#ifdef DEBUG
copy(directory_iterator(p), directory_iterator(),ostream_iterator<directory_entry>(cout,"\n"));
#endif
copy(directory_iterator(p), directory_iterator(), back_inserter(pathes));
for(auto iter = pathes.begin();iter != pathes.end();iter ++){
lstpFileNames.push_back(iter->generic_string());
}
return lstpFileNames;
}else{
#ifdef DEBUG
printf("No SubFiles In %s\n",m_pFileName);
#endif
}
return lstpFileNames;
}
CFileOpt::~CFileOpt(){
m_pFileName = NULL;
}

调用构造函数，传入文件夹的名字，通过mGetSubFiles()函数就可以返回文件夹内的文件路径

转载地址：http://blog.csdn.net/zyaiwx/article/details/11659335

感谢作者 zybjtu