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Extracting Path / Filename from a String

Posted by Chris Abbott on February 7th, 2004
This procedure takes a Windows compatible path and breaks it into the filename with extension and without extension, the extension alone, the path, and whether it's a valid file or not. 

option Explicit

private Type PathInfo
    FileNamewExt as string
    FileNamewoExt as string
    FileExt as string
    FilePath as string
    FileIsValid as Boolean
End Type

private Sub ExtractInfo(Source as string, _
        ReturnInfo as PathInfo)

    Dim intCurrentPos as Integer, intFileNamePos as Integer
    Dim intFileExtPos as Integer
    
    'clear UDT passed in if there is any existing data
    ReturnInfo.FileExt = ""
    ReturnInfo.FileIsValid = false
    ReturnInfo.FileNamewExt = ""
    ReturnInfo.FileNamewoExt = ""
    ReturnInfo.FilePath = ""

    If Source <> "" then

        'get file name by finding the last slash in the string
        Do
            intCurrentPos = InStr(intCurrentPos + 1, Source, "\", _
                            vbTextCompare)
            If intCurrentPos <> 0 then
                intFileNamePos = intCurrentPos
            else
                intFileNamePos = intFileNamePos + 1
                Exit Do
            End If
        Loop
        
        'get file extension position if any
        intFileExtPos = InStr(intFileNamePos, Source, ".", _
                        vbTextCompare) + 1
        If intFileExtPos = 1 then
            Exit Sub
        End If
    
        'put data in UDT passed in
        If intFileNamePos <> 1 then
            ReturnInfo.FileNamewExt = mid(Source, intFileNamePos, _
                                      len(Source) - intFileNamePos + 1)
            ReturnInfo.FilePath = mid(Source, 1, _
                                  intFileNamePos - 2)
        End If
        If intFileNamePos <> 1 And intFileExtPos <> 1 then
            ReturnInfo.FileNamewoExt = mid(Source, intFileNamePos, _
                                       intFileExtPos - _
                                       intFileNamePos - 1)
            ReturnInfo.FileExt = mid(Source, intFileExtPos, _
                                 len(Source) - intFileExtPos + 1)
        End If
        If Dir(Source, vbArchive + vbHidden + vbNormal + _
               vbReadOnly + vbSystem) <> "" then
            ReturnInfo.FileIsValid = true
        else
            ReturnInfo.FileIsValid = false
        End If

    End If

End Sub

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Comments

  • Good Code

    Posted by Legacy on 06/18/2002 12:00am

    Originally posted by: Rodrigo Silva

    Thanks to the Net that I found this solution: I know I could not be the first in having the problem that you solved

    Reply

  • Please send me a solution

    Posted by Legacy on 05/15/2002 12:00am

    Originally posted by: Manojkumar Vattakkat

    Dear friend

    If any one of you are having an .OCX/Function for JUSTIFY A TEXT BOX in VB (JUSTIFY means both
    left and right side of paragraph should be aligned properly. you can confirm it with typing a paragraph in
    MSWORD and press JUSTIFY button of FORMATTING tool bar after selecting the para.) , Kindly send me.
    It will be a greate help for me for doing some works in Visual basic 6.

    Regards
    Manojkumar Vattakkatt

    Reply

  • Try this approach

    Posted by Legacy on 07/27/2001 12:00am

    Originally posted by: Sameeg Kader 

    Function GetFilePath(filespec) As String

       'This would retrieve only the Path

      Dim fso

        Set fso = CreateObject("Scripting.FileSystemObject")

        GetFilePath = fso.GetParentFolderName(filespec)

    End Function


    Function GetFileName(filespec) As String

       'This would retrieve Filename including Extension

      Dim fso

        Set fso = CreateObject("Scripting.FileSystemObject")

        GetFileName = fso.GetFileName(filespec)

    End Function


    Function GetBaseName(filespec) As String

       'This would retrieve Filename excluding Extension

      Dim fso

        Set fso = CreateObject("Scripting.FileSystemObject")

        GetBaseName = fso.GetParentFolderName(filespec)

    End Function


    Function GetExtensionName(filespec) As String

       'This would retrieve on the File Extension

      Dim fso

        Set fso = CreateObject("Scripting.FileSystemObject")

        GetExtensionName= fso.GetFileName(filespec)

    End Function

    Reply

  • Extracting Path / Filename from a String

    Posted by Legacy on 07/24/2001 12:00am

    Originally posted by: v.udai kumar 

    instead of useing InStr() function and going for a do loop, simply use InStrRev() function and replace the do loop with a single line statement.


    EXISTING

    ========

    Do

    intCurrentPos = InStr(intCurrentPos + 1, Source, "\", vbTextCompare)

                If intCurrentPos <> 0 then

                    intFileNamePos = intCurrentPos

                else

                    intFileNamePos = intFileNamePos + 1

                    Exit Do

                End If

    Loop


    REPLACE IT WITH

    ===============

    intFileNamePos =1

    intFileNamePos = InStrRev(Source, "\") + 1

    Reply

  • Another bug

    Posted by Legacy on 05/18/2001 12:00am

    Originally posted by: Paul Groot

    This code also fails if the filename contains more than one dot (like "c:\temp\somefile.doc.zip").

    A more reliable aproach is to use FileSystemObject:

    Function GetTheBase(filespec)
    Dim fso
    Set fso = CreateObject("Scripting.FileSystemObject")
    GetTheBase = fso.GetBaseName(filespec)
    End Function

    Reply

  • Extracting Path / Filename from a String

    Posted by Legacy on 12/15/1999 12:00am

    Originally posted by: Jorge Patr�o 

    This procedure works OK, but there are some problems:

       1. It does not deal with filenames without extension

       2. It does not deal with filenames like C:FILENAME.EXT


    So, I made a few changes to your code.

    To correct the first problem, I just eliminated 3 lines of code:


            If intFileExtPos = 1 Then

                'Exit Sub

            End If


    This way, if there is no extension, FileNamewoExt="" and FileNamewExt=FILENAME.


    To solve the second problem, I made little changes:

    . Introduced a new IF block to check whether there's a    

      slash in the filename

    . Introduced a new variable, intCorrection, to deal with 2 

      possibilities of specifying the filename:

            C:FILENAME[.EXT]

            C:\FILENAME[.EXT]


    I also added a new field to the PathInfo structure: PathIsValid is a boolean that tells if the filepath is valid or not.          


    Here's the complete code:


    Option Explicit


    Private Type PathInfo

        FileNamewExt As String

        FileNamewoExt As String

        FileExt As String

        FilePath As String

        FileIsValid As Boolean

        PathIsValid As Boolean

    End Type


    

    Private Sub ExtractInfo(Source As String, ReturnInfo As PathInfo)


        Dim intCurrentPos As Integer, intFileNamePos As Integer

        Dim intFileExtPos, intCorrection As Integer

        

        'clear UDT passed in if there is any existing data

        ReturnInfo.FileExt = ""

        ReturnInfo.FileIsValid = False

        ReturnInfo.FileNamewExt = ""

        ReturnInfo.FileNamewoExt = ""

        ReturnInfo.FilePath = ""


        If Source <> "" Then


            'get file name by finding the last slash in the string

            Do

                intCurrentPos = InStr(intCurrentPos + 1, Source, "\", vbTextCompare)

                If intCurrentPos <> 0 Then

                    intFileNamePos = intCurrentPos

                Else

                    intFileNamePos = intFileNamePos + 1

                    Exit Do

                End If

            Loop

            

            'get file extension position if any

            intFileExtPos = InStr(intFileNamePos, Source, ".", vbTextCompare) + 1

            

            If intFileNamePos = 1 Then

                ' Filename specified as C:FILENAME or C:FILENAME.EXT

                intFileNamePos = 3

                intCorrection = 1

            Else

                intCorrection = 0

            End If

            'put data in UDT passed in

            If intFileNamePos <> 1 Then

                ReturnInfo.FileNamewExt = Mid(Source, intFileNamePos, Len(Source) - intFileNamePos + 1)

                ReturnInfo.FilePath = Mid(Source, 1, intFileNamePos - 2 + intCorrection)

            End If

            If intFileNamePos <> 1 And intFileExtPos <> 1 Then

                ReturnInfo.FileNamewoExt = Mid(Source, intFileNamePos, intFileExtPos - intFileNamePos - 1)

                ReturnInfo.FileExt = Mid(Source, intFileExtPos, Len(Source) - intFileExtPos + 1)

            End If

            If Dir(Source, vbArchive + vbHidden + vbNormal + vbReadOnly + vbSystem) <> "" Then

                ReturnInfo.FileIsValid = True

            Else

                ReturnInfo.FileIsValid = False

            End If

            If Dir(ReturnInfo.FilePath, vbDirectory) <> "" Then

                ReturnInfo.PathIsValid = True

            Else

                ReturnInfo.PathIsValid = False

            End If

        End If


    End Sub

    Reply
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