[Winmerge-user] deficiency of CompareMSExcelFiles

[TK S. <tee...@gm...>]

[same msg posted to open-discussion ML]

I have just started using WinMerge to compare MS-Excel files. Here's
my observation so far.

First, the output of CompareMSExcelFiles (used eventually for
comparison) are not structured very well, making it hard to locate the
sheets/modules/... on the differences.

Second, CompareMSExcelFiles becomes painfully slow when comparing
large files. In fact, I was never able to compare some files that
contains 100+ worksheet and modules (file size > 20MB), as I had to
kill WinMerge that appeared to have locked up on several tries.

A quick peek into the VB source suggested that it might be caused by
the fact that CompareMSExcelFiles actually try to capture all the data
in memory and only write them to the file for comparison at the end of
the capture cycle. On top of that, writing/reading the temp files
line-by-line may be yet another major factor.

Unfortunately I don't currently have the capability to develop on VB.
So I wonder if the maintainer of this plugin can help optimize it for
large Excel files. Thanks.