在使用PathFileExists输入参数LPCTSTR出错!!!下面是转来的方法,还没有验证!
判断文件夹是否存在:
1.用CreateDirectory(".\\FileManege",NULL);如果文件夹FileManege不存在,则创建。
2.或者if(_access(".\\FileManege",0)==-1),表示FileManege不存在。
3.或者BOOL PathIsDirectory(LPCTSTR pszPath);
二、判断文件是否存在:
1.用if((file=fopen(".\\FileManege\\F\\F.dat","rb"))==NULL)
file=fopen(".\\FileManege\\F\\F.dat","ab+"); // 先判断有无文件,没的话新建一个
2.用if(_access(".\\FileManege\\F\\F.dat",0)==-1),表示文件不存在。
函数int _access( const char *path, int mode );可以判断文件或者文件夹的mode属性
mode=00;//Existence only
mode=02;//Write permission
mode=04;//Read permission
mode=06;//Read and write permission
需要包含头文件<io.h>。
下面是从优快云论坛转来的
- #include < iostream >
- #include < fstream >
- using namespace std;
- #define FILENAME "stat.dat"
- int main()
- {
- fstream _file;
- _file.open(FILENAME,ios:: in );
- if ( ! _file)
- {
- cout << FILENAME << " 没有被创建 " ;
- }
- else
- {
- cout << FILENAME << " 已经存在 " ;
- }
- return 0 ;
- }
函数名: _access
功 能: 确定文件的访问权限
用 法: int access(const char *filename, int amode);
Determine file-access permission.
int _access( const char *path, int mode );
int _waccess( const wchar_t *path, int mode );
参考MSDN
Return Value
Each of these functions returns 0 if the file has the given mode. The function returns –1 if the named file does not exist or is not accessible in the given mode; in this case, errno is set as follows:
EACCES
Access denied: file’s permission setting does not allow specified access.
ENOENT
Filename or path not found.
Parameters
path
File or directory path
mode
Permission setting
Remarks
When used with files, the _access function determines whether the specified file exists and can be accessed as specified by the value of mode . When used with directories, _access determines only whether the specified directory exists; in Windows NT, all directories have read and write access.
mode Value Checks File For
00 Existence only
02 Write permission
04 Read permission
06 Read and write permission
Generic-Text Routine Mappings
TCHAR.H Routine | _UNICODE & _MBCS Not Defined | _MBCS Defined | _UNICODE Defined |
_taccess | _access | _access | _waccess |
Example
- /* ACCESS.C: This example uses _access to check the
- * file named "ACCESS.C" to see if it exists and if
- * writing is allowed.
- */
- #include <io.h>
- #include <stdio.h>
- #include <stdlib.h>
- void main( void )
- {
- /* Check for existence */
- if( (_access( "ACCESS.C", 0 )) != -1 )
- {
- printf( "File ACCESS.C exists/n" );
- /* Check for write permission */
- if( (_access( "ACCESS.C", 2 )) != -1 )
- printf( "File ACCESS.C has write permission/n" );
- }
- }
Output
File ACCESS.C exists File ACCESS.C has write permission
3.在windows平台下用API函数FindFirstFile(...):
(1)检查文件是否存在:
- #define _WIN32_WINNT 0x0400
- #include <windows.h>
- int main( int argc, char * argv[])
- {
- WIN32_FIND_DATA FindFileData;
- HANDLE hFind;
- printf ( " Target file is %s. " , argv[ 1 ]);
- hFind = FindFirstFile(argv[ 1 ], & FindFileData);
- if (hFind == INVALID_HANDLE_VALUE) {
- printf ( " Invalid File Handle. Get Last Error reports %d " , GetLastError ());
- } else {
- printf ( " The first file found is %s " , FindFileData.cFileName);
- FindClose(hFind);
- }
- return ( 0 );
- }
(2)检查某一目录是否存在:
- /// 目录是否存在的检查:
- bool CheckFolderExist( const string & strPath)
- {
- WIN32_FIND_DATA wfd;
- bool rValue = false ;
- HANDLE hFind = FindFirstFile(strPath.c_str(), & wfd);
- if ((hFind != INVALID_HANDLE_VALUE) && (wfd.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY))
- {
- rValue = true ;
- }
- FindClose(hFind);
- return rValue;
- }
4.使用boost的filesystem类库的exists函数
- #include < boost / filesystem / operations.hpp >
- #include < boost / filesystem / path.hpp >
- #include < boost / filesystem / convenience.hpp >
- int GetFilePath(std:: string & strFilePath)
- {
- string strPath;
- int nRes = 0 ;
- // 指定路径
- strPath = " D:/myTest/Test1/Test2 " ;
- namespace fs = boost::filesystem;
- // 路径的可移植
- fs::path full_path( fs::initial_path() );
- full_path = fs::system_complete( fs::path(strPath, fs::native ) );
- // 判断各级子目录是否存在,不存在则需要创建
- if ( ! fs::exists( full_path ) )
- {
- // 创建多层子目录
- bool bRet = fs::create_directories(full_path);
- if ( false == bRet)
- {
- return - 1 ;
- }
- }
- strFilePath = full_path.native_directory_string();
- return 0 ;
- }