Best method of determining path, relative path and/or flie name
in [Visual Basic]
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From: Tony Toews on 11 Jun 2010 18:06 Folks I have a string which must contain just a file name, a sub folder and file name or a complath path and file name. So what's the best means of validating it? This file could be in the same path as the VB6 EXE. The simplest approach would be to see if it starts with a \\ or x: where x is A-Z. If so then it's a path and file name. Otherwise it's a relative path and file name so insert the App.Path in front. Am I missing something? Tony
From: Karl E. Peterson on 11 Jun 2010 18:36 Tony Toews wrote: > Folks > > I have a string which must contain just a file name, a sub folder and > file name or a complath path and file name. So what's the best means > of validating it? This file could be in the same path as the VB6 > EXE. > > The simplest approach would be to see if it starts with a \\ or x: > where x is A-Z. If so then it's a path and file name. > > Otherwise it's a relative path and file name so insert the App.Path in > front. > > Am I missing something? To be sure I understand, you want to be sure it's a "valid" filename? Not necessarily that it exists? This function will tell you whether the path is relative or absolute, if that's what you're wanting: Private Declare Function PathIsRelativeW Lib "shlwapi" (ByVal lpszPath As Long) As Boolean Public Function PathIsRelative(ByVal Path As String) As Boolean ' Searches a path and determines if it is relative. PathIsRelative = PathIsRelativeW(StrPtr(Path)) End Function And this is my favorite way to build paths, now: Private Declare Function PathCombineW Lib "shlwapi" (ByVal lpszDest As Long, ByVal lpszDir As Long, ByVal lpszFile As Long) As Boolean Public Function PathCombine(ByVal Directory As String, ByVal File As String) As String Dim Buffer As String ' Concatenates two strings that represent properly formed ' paths into one path, as well as any relative path pieces. Buffer = String$(MAX_PATH, 0) If PathCombineW(StrPtr(Buffer), StrPtr(Directory), StrPtr(File)) Then PathCombine = TrimNull(Buffer) End If End Function PathCombine means you don't have to worry about backslashes anymore. (Requires Win98/2000 or IE4 or higher.) -- ..NET: It's About Trust! http://vfred.mvps.org Customer Hatred Knows No Bounds at MSFT ClassicVB Users Regroup! comp.lang.basic.visual.misc Free usenet access at http://www.eternal-september.org
From: Thorsten Albers on 11 Jun 2010 18:37 Tony Toews <ttoews(a)telusplanet.net> schrieb im Beitrag <dhc516tqmbea168re9b6u1erue8m8js9c5(a)4ax.com>... > I have a string which must contain just a file name, a sub folder and > file name or a complath path and file name. So what's the best means > of validating it? This file could be in the same path as the VB6 > EXE. > > The simplest approach would be to see if it starts with a \\ or x: > where x is A-Z. If so then it's a path and file name. > > Otherwise it's a relative path and file name so insert the App.Path in > front. > > Am I missing something? Another possibility is a drive/server+share specification with a file name without a diretcory path, e.g. C:autoexec.bat. In this case you have to remove the drive specification from App.Path and insert the remaining directory path between drive/server+share specification. But why App.Path? If a relative path is given, usually it is not relative to the application directory but to the current directory of the application (curdir$). My approach to this would be as follows: 1. Check, if the given relative or absolute path points to an existing file (GetFileAttributes() etc.) 2. Get the absolute file path by calling GetFullPathName() of the Windows API. Step 1 is necessary since on some version of windows GetFullPathName() sometimes returns curious results if the file does not exist.... Other usefull procedures for validating, etc. a path can be found in SHLWAPI.DLL (e.g. PathIsRelative()). -- Thorsten Albers albers (a) uni-freiburg.de
From: Karl E. Peterson on 11 Jun 2010 18:38 Tony Toews wrote: > Folks > > I have a string which must contain just a file name, a sub folder and > file name or a complath path and file name. So what's the best means > of validating it? This file could be in the same path as the VB6 > EXE. > > The simplest approach would be to see if it starts with a \\ or x: > where x is A-Z. If so then it's a path and file name. > > Otherwise it's a relative path and file name so insert the App.Path in > front. > > Am I missing something? It occurs to me you may want to do more than just realize whether the path is relative or not. Here's a function that will fully qualify a relative path based on the working directory: Private Declare Function PathSearchAndQualifyW Lib "shlwapi" (ByVal lpszPath As Long, ByVal lpszFullyQualifiedPath As Long, ByVal cchFullyQualifiedPath As Long) As Boolean Public Function PathQualify(ByVal Path As String) As String Dim Buffer As String ' Returns True if the path is correctly formatted and ' fully qualified. If the path name doesn't contain ' folder info, the name of the active directory is used ' to create a qualified path. Buffer = String$(MAX_PATH, 0) If PathSearchAndQualifyW(StrPtr(Path), StrPtr(Buffer), MAX_PATH) Then PathQualify = TrimNull(Buffer) End If End Function I realize that may not be what you want, because you seem to have an anchor at App.Path, but just in case? -- ..NET: It's About Trust! http://vfred.mvps.org Customer Hatred Knows No Bounds at MSFT ClassicVB Users Regroup! comp.lang.basic.visual.misc Free usenet access at http://www.eternal-september.org
From: Tony Toews on 11 Jun 2010 19:02
On Fri, 11 Jun 2010 15:36:00 -0700, Karl E. Peterson <karl(a)exmvps.org> wrote: >To be sure I understand, you want to be sure it's a "valid" filename? >Not necessarily that it exists? Yes, the file must exist. >(Requires Win98/2000 or IE4 or higher.) Yup, that's fine. Although a few years ago I did get a report of a bug in A2.0 which dates from 1994 and a few years before that a bug with NT 4.0. Tony |