看似一个简单的问题。。。。。。。关于文件指针
本帖最后由 setoy 于 2012-12-13 20:12:53 编辑 怎么输出文件指针对应文件的文件名呢？
是linux，命令提示符下编程，文件名仅为英文字母
void output_file_name (FILE *f1, FILE *f2)
{
//在这里输出f1的文件名，怎么搞？
}
//Obtaining a File Name From a File Handle
//
//GetFinalPathNameByHandle, introduced in Windows Vista and Windows Server 2008, will return a path from a handle.
//If you need to do this on earlier releases of Windows, the following example obtains a file name from a handle
//to a file object using a file mapping object. It uses the CreateFileMapping and MapViewOfFile functions to create
//the mapping. Next, it uses the GetMappedFileName function to obtain the file name. For remote files, it prints
//the device path received from this function. For local files, it converts the path to use a drive letter and prints
//this path. To test this code, create a main function that opens a file using CreateFile and passes the resulting
//handle to GetFileNameFromHandle.
#include <windows.h>
#include <stdio.h>
#include <tchar.h>
#include <string.h>
#include <psapi.h>
//#include <strsafe.h>
#define BUFSIZE 512
BOOL GetFileNameFromHandle(HANDLE hFile)
{
BOOL bSuccess = FALSE;
TCHAR pszFilename[MAX_PATH+1];
HANDLE hFileMap;
// Get the file size.
DWORD dwFileSizeHi = 0;
DWORD dwFileSizeLo = GetFileSize(hFile, &dwFileSizeHi);
if( dwFileSizeLo == 0 && dwFileSizeHi == 0 )
{
_tprintf(TEXT("Cannot map a file with a length of zero.\n"));
return FALSE;
}
// Create a file mapping object.
hFileMap = CreateFileMapping(hFile,
NULL,
PAGE_READONLY,
0,
1,
NULL);
if (hFileMap)
{
// Create a file mapping to get the file name.
void* pMem = MapViewOfFile(hFileMap, FILE_MAP_READ, 0, 0, 1);
if (pMem)
{
if (GetMappedFileNameA (GetCurrentProcess(),
pMem,
pszFilename,
MAX_PATH))
{
// Translate path with device name to drive letters.
TCHAR szTemp[BUFSIZE];
szTemp[0] = '\0';
if (GetLogicalDriveStrings(BUFSIZE-1, szTemp))
{
TCHAR szName[MAX_PATH];
TCHAR szDrive[3] = TEXT(" :");
BOOL bFound = FALSE;
TCHAR* p = szTemp;
do
{
// Copy the drive letter to the template string
*szDrive = *p;
// Look up each device name
if (QueryDosDevice(szDrive, szName, MAX_PATH))
{
size_t uNameLen = _tcslen(szName);
if (uNameLen < MAX_PATH)
{
bFound = _tcsnicmp(pszFilename, szName, uNameLen) == 0
&& *(pszFilename + uNameLen) == _T('\\');
if (bFound)
{
// Reconstruct pszFilename using szTempFile
// Replace device path with DOS path
TCHAR szTempFile[MAX_PATH];
sprintf(szTempFile,
TEXT("%s%s"),
szDrive,
pszFilename+uNameLen);
strcpy(pszFilename, szTempFile);
}
}
}
// Go to the next NULL character.
while (*p++);
} while (!bFound && *p); // end of string
}
}
bSuccess = TRUE;
UnmapViewOfFile(pMem);
}
CloseHandle(hFileMap);
}
_tprintf(TEXT("File name is %s\n"), pszFilename);
return(bSuccess);
}
int _tmain(int argc, TCHAR *argv[])
{
HANDLE hFile;
if( argc != 2 )
{
_tprintf(TEXT("This sample takes a file name as a parameter.\n"));
return 0;
}
hFile = CreateFile(argv[1], GENERIC_READ, FILE_SHARE_READ, NULL,
OPEN_EXISTING, 0, NULL);
if(hFile == INVALID_HANDLE_VALUE)
{
_tprintf(TEXT("CreateFile failed with %d\n"), GetLastError());
return 0;
}
GetFileNameFromHandle( hFile );
}
void output_file_name(FILE* fp)
{
char target_path[256];
char file_path[256];
int fd=fileno(fp);
pid_t pid=getpid();
sprintf(file_path,"/proc/%d/fd/%d",pid,fd);
int len=readlink(file_path,target_path,256);
if(len==-1){
printf("readlink error!");
return;
}
target_path[len]='\0';
printf("Path=%s\n",target_path);
}
