GetFullPathNameA function (fileapi.h)

Article
02/09/2023

Retrieves the full path and file name of the specified file.

To perform this operation as a transacted operation, use the GetFullPathNameTransacted function.

For more information about file and path names, see File Names, Paths, and Namespaces.

Note See the Remarks section for discussion of the use of relative paths with the GetFullPathName function in multithreaded applications or shared library code.

Syntax

DWORD GetFullPathNameA(
  [in]  LPCSTR lpFileName,
  [in]  DWORD  nBufferLength,
  [out] LPSTR  lpBuffer,
  [out] LPSTR  *lpFilePart
);

Parameters

[in] lpFileName

The name of the file.

This parameter can be a short (the 8.3 form) or long file name. This string can also be a share or volume name.

[in] nBufferLength

The size of the buffer to receive the null-terminated string for the drive and path, in TCHARs.

[out] lpBuffer

A pointer to a buffer that receives the null-terminated string for the drive and path.

[out] lpFilePart

A pointer to a buffer that receives the address (within lpBuffer) of the final file name component in the path.

This parameter can be NULL.

If lpBuffer refers to a directory and not a file, lpFilePart receives zero.

Return value

If the function succeeds, the return value is the length, in TCHARs, of the string copied to lpBuffer, not including the terminating null character.

If the lpBuffer buffer is too small to contain the path, the return value is the size, in TCHARs, of the buffer that is required to hold the path and the terminating null character.

If the function fails for any other reason, the return value is zero. To get extended error information, call GetLastError.

Remarks

GetFullPathName merges the name of the current drive and directory with a specified file name to determine the full path and file name of a specified file. It also calculates the address of the file name portion of the full path and file name.

This function does not verify that the resulting path and file name are valid, or that they see an existing file on the associated volume.

Note that the lpFilePart parameter does not require string buffer space, but only enough for a single address. This is because it simply returns an address within the buffer that already exists for lpBuffer.

Share and volume names are valid input for lpFileName. For example, the following list identities the returned path and file names if test-2 is a remote computer and U: is a network mapped drive whose current directory is the root of the volume:

If you specify "\\test-2\q$\lh" the path returned is "\\test-2\q$\lh"
If you specify "\\?\UNC\test-2\q$\lh" the path returned is "\\?\UNC\test-2\q$\lh"
If you specify "U:" the path returned is the current directory on the "U:\" drive

GetFullPathName does not convert the specified file name, lpFileName. If the specified file name exists, you can use GetLongPathName or GetShortPathName to convert to long or short path names, respectively.

If the return value is greater than or equal to the value specified in nBufferLength, you can call the function again with a buffer that is large enough to hold the path. For an example of this case in addition to using zero-length buffer for dynamic allocation, see the Example Code section.

Note Although the return value in this case is a length that includes the terminating null character, the return value on success does not include the terminating null character in the count.

Relative paths passed to the GetFullPathName function are interpreted as relative to the process's current directory. The current directory state written by the SetCurrentDirectory function is global to the process and can be changed by any thread at any time. Applications should be aware that consecutive calls to the GetFullPathName function with a relative path may produce different results if the current directory changes between the two calls.

To avoid problems caused by inconsistent results, multithreaded applications and shared library code should avoid using relative paths. If a relative path is received, it should be consumed exactly once, either by passing the relative path directly to a function like CreateFile, or by converting it to an absolute path and using the absolute path from that point forward.

In Windows 8 and Windows Server 2012, this function is supported by the following technologies.

Technology	Supported
Server Message Block (SMB) 3.0 protocol	Yes
SMB 3.0 Transparent Failover (TFO)	Yes
SMB 3.0 with Scale-out File Shares (SO)	Yes
Cluster Shared Volume File System (CsvFS)	Yes
Resilient File System (ReFS)	Yes

Examples

The following C++ example shows a basic use of GetFullPathName, GetLongPathName, and GetShortPathName. For another example using dynamic allocation, see GetShortPathName.

#include <windows.h>
#include <tchar.h>
#include <stdio.h>

#define BUFSIZE 4096
#define LONG_DIR_NAME TEXT("c:\\longdirectoryname")

void _tmain(int argc, TCHAR *argv[])
{
    DWORD  retval=0;
    BOOL   success; 
    TCHAR  buffer[BUFSIZE]=TEXT(""); 
    TCHAR  buf[BUFSIZE]=TEXT(""); 
    TCHAR** lppPart={NULL};

   if( argc != 2 )
   {
      _tprintf(TEXT("Usage: %s [file]\n"), argv[0]);
      return;
   }

// Retrieve the full path name for a file. 
// The file does not need to exist.

    retval = GetFullPathName(argv[1],
                 BUFSIZE,
                 buffer,
                 lppPart);
    
    if (retval == 0) 
    {
        // Handle an error condition.
        printf ("GetFullPathName failed (%d)\n", GetLastError());
        return;
    }
    else 
    {
        _tprintf(TEXT("The full path name is:  %s\n"), buffer);
        if (lppPart != NULL && *lppPart != 0)
        {
            _tprintf(TEXT("The final component in the path name is:  %s\n"), *lppPart);
        }
    }


// Create a long directory name for use with the next two examples.

    success = CreateDirectory(LONG_DIR_NAME,
                              NULL);

    if (!success)
    {
        // Handle an error condition.
        printf ("CreateDirectory failed (%d)\n", GetLastError());
        return;
    }


// Retrieve the short path name.  

    retval = GetShortPathName(LONG_DIR_NAME,
                  buf,
                  BUFSIZE);

    if (retval == 0) 
    {
        // Handle an error condition.
         printf ("GetShortPathName failed (%d)\n", GetLastError());
         return;
    }
    else _tprintf(TEXT("The short name for %s is %s\n"), 
                  LONG_DIR_NAME, buf);


// Retrieve the long path name.  

    retval = GetLongPathName(buf,
              buffer,
              BUFSIZE);

    if (retval == 0) 
    {
        // Handle an error condition.
         printf ("GetLongPathName failed (%d)\n", GetLastError());
         return;
    }
    else _tprintf(TEXT("The long name for %s is %s\n"), buf, buffer);

// Clean up the directory.

    success = RemoveDirectory(LONG_DIR_NAME);
    if (!success)
    {
        // Handle an error condition.
        printf ("RemoveDirectory failed (%d)\n", GetLastError());
        return;
    }
}

Note

The fileapi.h header defines GetFullPathName as an alias which automatically selects the ANSI or Unicode version of this function based on the definition of the UNICODE preprocessor constant. Mixing usage of the encoding-neutral alias with code that not encoding-neutral can lead to mismatches that result in compilation or runtime errors. For more information, see Conventions for Function Prototypes.

Requirements

Requirement	Value
Minimum supported client	Windows XP [desktop apps \| UWP apps]
Minimum supported server	Windows Server 2003 [desktop apps \| UWP apps]
Target Platform	Windows
Header	fileapi.h (include Windows.h)
Library	Kernel32.lib
DLL	Kernel32.dll

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