Only short filenames must be used so I need to convert long filename to short filename

[Naveed Anis]

Please reply immediately cause my task is
on the verge of being lost.

I just want to know; how can we convert long
filenames to short filenames.



A problem stays like a challenge till
I find the solution to it.

[Lothar Haensler]

use the GetShortPathName API!

[Naveed Anis]

I am using it from VB.
Can I get an example please!

A problem stays like a challenge till
I find the solution to it.

[Lothar Haensler]

Option Explicit
Private Declare Function GetShortPathName Lib "kernel32" _
Alias "GetShortPathNameA" (ByVal lpszLongPath as String _
, ByVal lpszShortPath as String, ByVal cchBuffer as Long) as Long

Private Sub Command1_Click()
Dim l as Long
Dim strLong as string * 255
Dim strshort as string * 255
strLong = "c:\winnt\niagnt32_install.log"
l = GetShortPathName(strLong, strshort, len(strLong))
MsgBox strshort
End Sub


tested with NT 4 and VB 6

[Naveed Anis]

I am very very thankful to you.
You have saved my day.
If there was anything more thanks
I could do, I would be obliged to do it.

If I have any other problems, can I contact
you?

if yes then; if you don't have problem with
that; then
please mail me at: naveed_anis_kh@yahoo.com

A problem stays like a challenge till
I find the solution to it.

[Lothar Haensler]

>If I have any other problems, can I contact
you?

the easiest way to contact "me" is by posting your question to this forum.
That way you have access to the knowledge of all other forum participants.

[Billkamm]

Hi, when using that function it fills the rest of the buffer with NULL characters (maybe the \0 character from c++ not sure).

Is there a VB function to remove the rest of that stuff from the buffer, so I can have just the short path as my string.

[Billkamm]

Ok I found a way around this using the following function:

Private Function VbNullTrim(strTextToTrim As String) As String
Dim lngPosition As Long ' Position of the NULL character

' Find the position of the first vbNullChar
lngPosition = InStr(strTextToTrim, vbNullChar)

' Trim the vbNullChars off the string
If lngPosition > 0 Then
VbNullTrim = Left$(strTextToTrim, lngPosition - 1)
Else
VbNullTrim = strTextToTrim
End If
End Function

Does anyone know of a built-in function to do this?

[Billkamm]

I have run into another problem with this code.

I read the documentation at:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/fileio/base/getshortpathname.asp

And found out that you shouldn't use len(strLong) as the size of the buffer. For example "c:\a b" converts as "c:\ab~1" which is longer that long filename's length.

The full short path can get quite longer than the long path sometimes (ironic in a way), so it is highly recommended you check to make the return value is not greater than the buffer size you are using

[Billkamm]

One more note, after I remove the vbNullChar from that buffer I have to Trim() the buffer and assign it to another String.

[Cimperiali]

[...]you shouldn't use len(strLong) as the size of the buffer

Dim strLong as string * 255
means it is a fixed len string
you can fill it with a single char, but it will always be 255 in len
Thus
strLong="a"
msgbox len(strLong) 'you see 255!


Api guide shows this example:

Private Declare Function GetShortPathName Lib "kernel32" Alias "GetShortPathNameA" (ByVal lpszLongPath As String, ByVal lpszShortPath As String, ByVal lBuffer As Long) As Long
Public Function GetShortPath(strFileName As String) As String
'KPD-Team 1999
'URL: http://www.allapi.net/
'E-Mail: KPDTeam@Allapi.net
Dim lngRes As Long, strPath As String
'Create a buffer
strPath = String$(165, 0)
'retrieve the short pathname
lngRes = GetShortPathName(strFileName, strPath, 164)
'remove all unnecessary chr$(0)'s
GetShortPath = Left$(strPath, lngRes)
End Function
Private Sub Form_Load()
MsgBox GetShortPath("c:\Program Files\")
End Sub