source: Include/Classes/System/IO/Path.ab@ 61

Class Path
Public
    Static AltDirectorySeparatorChar = &H2F As Byte '/
    Static DirectorySeparatorChar = &H5C As Byte    '\
    Static PathSeparator = &H3B As Byte             ';
    Static VolumeSeparatorChar = &H3A As Byte       ':

    Static Function GetFileName(path As String) As String
        path.Remove(0, getLastSeparatorPosision(path) + 1)
        Return path
    End Function

    Static Function GetFileNameWithoutExtension(path As String) As String
        Dim fileName As String
        Dim extPos As Long

        fileName = GetFileName(path)
        extPos = getExtensionPosition(fileName)
        If extPos = -1 Then Return ""

        fileName.Remove(extPos)
        Return fileName
    End Function

    '手抜き
    Static Function GetRandomFileName() As String
        Randomize
        Dim temp As Long
        temp = Rnd() * 900000000 + 10000000
        Return Str$(temp)
    End Function

    Static Function GetExtension(path As String) As String
        Dim extPos As Long
        extPos = getExtensionPosition(path)
        If extPos = -1 Then Return ""

        path.Remove(0, extPos)
        Return path
    End Function
    
    Static Function ChangeExtension(path As String, extension As String) As String
        Dim extPos As Long
        extPos = getExtensionPosition(path)
        If extPos => 0 Then
            path.Remove(extPos)
        End If

        Return path + extension
    End Function

    Static Function HasExtension(ByRef path As String) As BOOL
        If GetExtension(path) <> "" Then
            Return _System_TRUE
        Else
            Return _System_FALSE
        End If
    End Function

    Static Function GetTempFileName() As String
        ' TODO: 実装
    End Function

    Static Function GetTempPath() As String
        GetTempPath.ReSize(__GetTempPath(0, 0) - 1)
        __GetTempPath(GetTempPath.Length + 1, GetTempPath)
    End Function

    Static Function GetFullPath(path As String) As String
        Dim cd As String
        cd.ReSize = GetCurrentDirectory(0, 0) - 1
        GetCurrentDirectory(cd.Length + 1, cd)

        Dim dirSepChar As String(Chr$(DirectorySeparatorChar))
        Return cd + dirSepChar + path
    End Function

    Static Function GetDirectoryName(path As String) As String
        Dim lastSepPos As Long
        lastSepPos = getLastSeparatorPosision(path)
        If lastSepPos = -1 Then Return ""

        path.Remove(lastSepPos)
        If path.Length <= 3 Then
            If IsPathRooted(path) Then Return ""
        End If
        Return path
    End Function

    Static Function GetPathRoot(path As String) As String
        If IsPathRooted(path) Then
            path.Remove(3)
            Return path
        Else
            Return ""
        End If
    End Function

    Static Function IsPathRooted(path As String) As BOOL
        Dim volSepChar As String(Chr$(VolumeSeparatorChar))
        If path.IndexOf(volSepChar, 1, 1) = 1 Then
            Return _System_TRUE
        Else
            Return _System_FALSE
        End If
    End Function

    Static Function Combine(path1 As String, path2 As String) As String
        Dim volSepChar As String(Chr$(VolumeSeparatorChar))
        Dim dirSepChar As String(Chr$(DirectorySeparatorChar))
        If path1.LastIndexOf(volSepChar) And path1.Length = 2 Then
            Return path1 + path2
        End If

        If path1.LastIndexOf(dirSepChar, ELM(path1.Length), 1) = -1 Then
            Return path1 + dirSepChar + path2
        Else
            Return path1 + path2
        End If
    End Function

Private
    Static Function getExtensionPosition(ByRef path As String) As Long
        Dim lastSepPos As Long
        lastSepPos = getLastSeparatorPosision(path)
        getExtensionPosition = path.LastIndexOf(".", ELM(path.Length), path.Length - lastSepPos)
    End Function

    Static Function getLastSeparatorPosision(ByRef path As String) As Long
        Dim dirSepChar As String(Chr$(DirectorySeparatorChar))
        Dim lastSepPos As Long
        lastSepPos = path.LastIndexOf(dirSepChar)

        If lastSepPos = -1 Then
            Dim volSepChar As String(Chr$(VolumeSeparatorChar))
            lastSepPos = path.LastIndexOf(volSepChar)
        End If
        Return lastSepPos
    End Function
End Class

'今はメソッド内で使えないので、実装されるまで回避
Function __GetTempPath(nBufferLength As DWord, lpBuffer As LPSTR) As DWord
    Return GetTempPath(nBufferLength, lpBuffer)
End Function