Question

Using VBA with a reference to Microsoft Scripting Runtime. I’m trying to compare filenames in two different directories, to find whether or not the same file is in both directories. However, I’m not looking for an exact match; I’d like to strip certain types of prefixes off, so, e.g., A-12234.pdf, 12234.pdf, and A_ 12234.pdf should be considered equal to each other.

Let’s say I have a function stripPrefix() that performs the necessary string operations to change a filename into a version that can be compared with others–in the prior case, stripPrefix() would return 12234.pdf for all 3. Then I could compare filenames in directories c:\dir1 and c:\dir2 using the following code:

sub findMatchFilenames()

dim fso as fileSystemObject
dim dir1 as folder
dim dir2 as folder
dim file1 as file
dim file2 as file

set fso=new fileSystemObject
set dir1=fso.getfolder("c:\dir1")
set dir2=fso.getfolder("c:\dir2")
for each file1 in dir1.files
 for each file2 in dir2.files
  if stripPrefix(file1.name)=stripPrefix(file2.name) then
   debug.print file1.name & " matches " & file2.name
  end if
 next file2
next file1

end sub

Big problem here: I’m calling stripPrefix() for the same filenames in dir2 every time I iterate the for..next file1 loop. I could build arrays dir1Array and dir2Array of stripped versions of each filename, but it seems I can’t correlate them with the Files collections in dir1 and dir2 because Files collections don’t have numerical indexes. I know because I tried using:

Set fso = New FileSystemObject
Set folderObj = fso.GetFolder("c:\data")
fileCount = folderObj.Files.Count
For c = 1 To fileCount
    MsgBox c & " " & folderObj.Files(c).name
Next

and got an “Invalid procedure call or argument” from folderObj.Files(c).name. I suppose I could increment a counter as I go in the for..next loops and use the counter to refer back to the array, like:

'after creating arrays of stripPrefix() for dir1 and dir2
ctr1=0
for each file1 in dir1.files
 ctr2=0
 for each file2 in dir2.files
  if dir1array(ctr1)=dir2array(ctr2) then
   debug.print file1.name & " matches " & file2.name
  end if
  ctr2=ctr2+1
 next file2
 ctr1=ctr1+1
next file1

but that seems really clunky. Is there a better way to handle this filename comparison operation?

Answer 1

Why not make a dictionary object of directory 2 and then search that using directory 1. You can strip off the prefixes when inserting into the dictionary object.

Only problem is, you might not then have a unique filename in the dictionary

For example A-12345 would be the same as A12345 after stripping the prefix