CMakeList.txt:

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1 cmake_minimum_required(VERSION 3.8) 2 project(Demo) 3  4 set(CMAKE_CXX_STANDARD 11) 5  6 set(SOURCE_FILES main.cpp) 7  8 //需要添加filesystem组件 9 find_package(Boost REQUIRED COMPONENTS system filesystem)10 11 if (Boost_FOUND)12     INCLUDE_DIRECTORIES(${Boost_INCLUDE_DIRS})13     add_executable(Demo ${SOURCE_FILES})14     target_link_libraries(Demo ${Boost_LIBRARIES})15 endif ()16 17 find_package(Boost REQUIRED COMPONENTS system)

 

 

boost::filesystem

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boost::filesystem库的核心类是path类,他屏蔽了不同文件系统的差异,使用了可移植的POSIX语法提供了通用的目录和路径表示,并且支持POSIX的符号链接

 

 

 

boost::filesystem::path

 

 

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path的构造函数可接受char*类型和string类型的参数构造，也可以是一个字符串迭代范围,路径的分割符由constexpr preferred_separator定义,UNIX是正斜杠(/),WINDOWS是反斜杠(\),C++中需要转义;

path使用的是POSIX语法标准,使用正斜杠(/)来分割目录,(./)代表当前路径,(..)代表当前目录上层; 

path类中基本实现了大部分文件属性操作，具体查看官方文档,以下只做了少部分测试

 

基本方法:

 

1 #include 
     
       2 #include 
      
        3  4  5 int 6 main(int argc, char **argv) 7 { 8     //因为文件属于程序外的不可控资源，随时抛出异常,try{}catch处理 9     try10     {11         //unix12         boost::filesystem::path path1("./Demo/Demo.txt");13         //windows14         boost::filesystem::path path2("C:\\Boost\\Demo\\include\\");15 16         //空路径,可用empty()判断17         boost::filesystem::path path3;18         assert(path3.empty());19 20         //path构造时不会检查路径的合法性(可使用函数判断)21         boost::filesystem::path path4("asdwqdqdasd");22 23 24         boost::filesystem::path path5("/usr/local/include/");25         auto path6 = path5 / "boost/filesystem/";                    //path重载了operator/()方法可追加路径26         std::cout << path6 << std::endl;                             //path重载operator<
      
     

 

 

查看磁盘和当前路径,修改文件时间(linux::touch)

1 #include 
     
       2 #include 
      
        3 #include 
       
         4  5 int 6 main() 7 { 8     //因为文件属于程序外的不可控资源，随时抛出异常,try{}catch处理 9     try10     {11 12         boost::filesystem::path path("/Users/xuaidong/Desktop/test.txt");13         boost::filesystem::path path1("/Users/xuaidong");14         //进入(程序启动时)main函数时的路径15         std::cout << boost::filesystem::initial_path() << std::endl;16         //返回当前路径，和initial_path()都是返回绝对路径(完整路径)17         std::cout << boost::filesystem::current_path() << std::endl;18 19 20         assert(boost::filesystem::is_regular_file(path));21 22         //返回文件最后一次修改时间23         std::cout << boost::filesystem::last_write_time(path) << std::endl;24         //更改文件修改时间(linux touch)25         boost::filesystem::last_write_time(path, time(0));26         std::cout << boost::filesystem::last_write_time(path) << std::endl;27 28         //查看磁盘空间29 30         boost::filesystem::space_info sp = boost::filesystem::space(path);31         std::cout << "磁盘空间: " << sp.capacity / boost::giga::num << std::endl;32         std::cout << "磁盘可用空间: " << sp.free / boost::giga::num << std::endl;33         std::cout << "磁盘可用空间: " << sp.available / boost::giga::num << std::endl;34 35 36         std::cout << boost::filesystem::file_size(path) << std::endl;37 38 39     }40     catch (boost::filesystem::filesystem_error &e)41     {42 43         std::cout << e.path1() << std::endl;44         std::cout << e.path2() << std::endl;45         std::cout << e.what() << std::endl;46     }47 48 49     return 0;50 }51
       
      
     

 

创建目录,删除目录,拷贝文件

1 #include 
     
       2 #include 
      
        3 #include 
       
         4  5 int 6 main(int argc, char **argv) 7 { 8     //因为文件属于程序外的不可控资源，随时抛出异常,try{}catch处理 9     try10     {11         boost::filesystem::path path("/Users/xuaidong/Desktop/ABABAB");12 13         //assert(boost::filesystem::is_regular_file(path));14         assert(boost::filesystem::is_directory(path));15 16         //删除空目录/文件17         //boost::filesystem::remove(path);18         //递归删除多个目录或者文件19         boost::filesystem::remove_all(path);20 21 22         //根据path创建一个目录23         boost::filesystem::create_directories(path);24         assert(boost::filesystem::exists(path));25         //拷贝文件到这个目录下26         boost::filesystem::copy_file("/Users/xuaidong/Desktop/Some.txt", path / "Some2.txt");27 28         //重命名29         boost::filesystem::rename(path/"Some2.txt",path/"Demo.txt");30 31         //创建多及目录32         boost::filesystem::create_directories(path/"Director1"/"Director2"/"Director3");33 34 35     }36     catch (boost::filesystem::filesystem_error &e)37     {38 39         std::cout << e.path1() << std::endl;40         std::cout << e.path2() << std::endl;41         std::cout << e.what() << std::endl;42     }43 44 45     return 0;46 }47
       
      
     

 

使用boost::filesystem::director_iterator迭代当前目录下文件(不向下层目录迭代),但是也可实现目录下层目录循环递归,其实boost也提供了boost::filesystem::recursive_directory_iterator向下递归而且遍历目录是可控制的(深度/浅度),且速度比递归的director_itertaor快

 

1 #include 
     
        2 #include 
      
         3 #include 
       
          4   5 void resource_direction(const boost::filesystem::path& path)  6 {  7     //递归文件目录下的所有文件路径  8     boost::filesystem::directory_iterator end;  9     for(boost::filesystem::directory_iterator begin(path);begin!=end;begin++) 10     { 11         //如果是目录继续向下解析 12         if (boost::filesystem::is_directory(*begin)) 13             resource_direction(*begin); 14         else 15             std::cout<<*begin<
        
          48 #include 
         
           49 #include 
          
            50 #include 
           
          
         
        
       
      
     

 

实例1:实现简单文件查找

1 #include 
     
       2 #include 
      
        3 #include 
       
         4 #include 
        
          5  6 //boost filesystem realize find file 7  8 boost::optional
         
           find_file(const boost::filesystem::path& path,const std::string& file) 9 {10     typedef boost::optional
          
            result_value;11 if (!boost::filesystem::exists(path)&&!boost::filesystem::is_directory(path))12 return result_value();13 14 //递归目录查找15 boost::filesystem::recursive_directory_iterator end;16 for(boost::filesystem::recursive_directory_iterator iter(path);iter!=end;++iter)17 {18 if (!boost::filesystem::is_directory(*iter)&&iter->path().filename()==file)19 return result_value(iter->path());20 }21 22 return result_value();23 }24 25 26 27 int28 main(int argc, char **argv)29 {30 //因为文件属于程序外的不可控资源，随时抛出异常,try{}catch处理31 try32 {33 auto path=find_file("/Users/xuaidong/Desktop/","application.cpp");34 35 if (path)36 {37 std::cout<<"CMakeLists.txt is here: "<<*path<
          
         
        
       
      
     

 

实例2:利用boost::xpressive正则匹配实现模糊查找(只实现"*"匹配)

 

1 #include 
     
       2 #include 
      
        3 #include 
       
         4 #include 
        
          5 #include 
         
           6  7 //boost filesystem realize obscure find file 8  9 std::vector
          
           10 find_file(const boost::filesystem::path &path, const std::string &file)11 {12 13 //之后查找使用- -14 static boost::xpressive::sregex_compiler rc; //正则表达式工厂15 if (!rc[file].regex_id())16 {17 std::string str = boost::replace_all_copy(boost::replace_all_copy(file, ".", "\\."), "*", ".*");18 rc[file] = rc.compile(str);19 }20 21 22 typedef std::vector
           
             result_value;23 result_value v;24 if (!boost::filesystem::exists(path) && !boost::filesystem::is_directory(path))25 {26 return v;27 }28 29 //递归目录查找30 boost::filesystem::recursive_directory_iterator end;31 for (boost::filesystem::recursive_directory_iterator iter(path); iter != end; ++iter)32 {33 if (!boost::filesystem::is_directory(*iter) &&34 boost::xpressive::regex_match(iter->path().filename().string(), rc[file]))35 {36 v.push_back(iter->path());37 }38 }39 40 return v;41 }42 43 44 int45 main(int argc, char **argv)46 {47 //因为文件属于程序外的不可控资源，随时抛出异常,try{}catch处理48 try49 {50 auto path = find_file("/Users/xuaidong/Desktop/", "*.txt");51 52 for (auto &iter:path)53 {54 std::cout << "file match: " << iter << std::endl;55 }56 57 58 }59 catch (boost::filesystem::filesystem_error &e)60 {61 62 std::cout << e.path1() << std::endl;63 std::cout << e.path2() << std::endl;64 std::cout << e.what() << std::endl;65 }66 67 68 return 0;69 }70
           
          
         
        
       
      
     

 

实例3:实现目录文件拷贝(空目录也考了)

 

1 #include 
     
        2 #include 
      
         3 #include 
       
          4 #include 
        
           5 #include 
         
            6 #include 
          
            7 8 9 std::vector
           
             10 find_file(const boost::filesystem::path &path, const std::string &file) 11 { 12 13 //之后查找使用- - 14 static boost::xpressive::sregex_compiler rc; //正则表达式工厂 15 if (!rc[file].regex_id()) 16 { 17 std::string str = boost::replace_all_copy(boost::replace_all_copy(file, ".", "\\."), "*", ".*"); 18 rc[file] = rc.compile(str); 19 } 20 21 22 typedef std::vector
            
              result_value; 23 result_value v; 24 if (!boost::filesystem::exists(path) && !boost::filesystem::is_directory(path)) 25 { 26 return v; 27 } 28 29 //递归目录查找 30 boost::filesystem::recursive_directory_iterator end; 31 for (boost::filesystem::recursive_directory_iterator iter(path); iter != end; ++iter) 32 { 33 if (boost::xpressive::regex_match(iter->path().filename().string(), rc[file])) 34 { 35 v.push_back(iter->path()); 36 } 37 } 38 39 return v; 40 } 41 42 43 std::size_t 44 copy_files( 45 const boost::filesystem::path &from_dir, 46 const boost::filesystem::path &to_dir, 47 const std::string &filename = "*" 48 ) 49 { 50 if (!boost::filesystem::exists(from_dir)) 51 { 52 std::cout << "file not find" << std::endl; 53 return -1; 54 } 55 56 57 std::cout << "prepare copy please wait....." << std::endl; 58 auto vcontain = find_file(from_dir, filename); 59 60 if (vcontain.empty()) 61 { 62 std::cout << "file is empty" << std::endl; 63 return -1; 64 } 65 66 67 boost::filesystem::path temp; 68 boost::progress_display display(vcontain.size()); 69 70 for (auto &iter:vcontain) 71 { 72 temp = to_dir / iter.string().substr(from_dir.string().length()); 73 std::cout << "file: " << temp << std::endl; 74 if (!boost::filesystem::exists(temp.parent_path())) 75 { 76 boost::filesystem::create_directories(temp.parent_path()); 77 } 78 79 if(boost::filesystem::is_directory(iter)) 80 { 81 boost::filesystem::create_directories(temp); 82 } 83 else{ 84 boost::filesystem::copy_file(iter, temp, boost::filesystem::copy_option::overwrite_if_exists); 85 } 86 87 ++display; 88 } 89 90 std::cout << vcontain.size() << " filed copyed" << std::endl; 91 92 return vcontain.size(); 93 94 } 95 96 97 int 98 main(int argc, char **argv) 99 {100 //因为文件属于程序外的不可控资源，随时抛出异常,try{}catch处理101 try102 {103 copy_files("/Users/xuaidong/Desktop/Boost", "/Users/xuaidong/Desktop/Test");104 105 106 }107 catch (boost::filesystem::filesystem_error &e)108 {109 110 std::cout << e.path1() << std::endl;111 std::cout << e.path2() << std::endl;112 std::cout << e.what() << std::endl;113 }114 115 116 }117