Compare very large files: need indication of what the difference is

[Gerdd]

Often I already know the files are "DIFFERENT", but a small indication of what the difference would look like would be a great help - a display mode that skips the non-different parts could be the answer; sort of like what happens when it skips forward to the first (and later next) difference.

I know this has been requested before, but it stays on my wish list ...

[Horst.Epp]

There is already the option "Show only differences, with extra line".

[Gerdd]

Ah, thanks, hadn't noticed - let me try that ...

[Gerdd]

That could be a great way, except - it doesn't help:

mark two files,
files->compare by contents (no way to mark the option at this stage) ... "not enough space ... DIFFERENT"
now I have the header with the clickable option, so I click it and click "compare" ... "not enough space ... DIFFERENT"

so, same as before. In all fairness, I was using two completely different 5GB files for this test. But it would have helped me to see if the differences start at the first byte or some 10 MB into the files or if there are only a few differences rather than completely different files.

[Dalai]

If you use TC 32-bit, try TC 64-bit instead for such tasks. If you already use TC 64-bit, then reboot your system. The compare by contents feature requires contiguous (i.e. non-fragmented) memory to read the files into. Memory fragments more and more the longer the system runs.

Regards
Dalai

[Horst.Epp]

That could be a great way, except - it doesn't help:

mark two files,
files->compare by contents (no way to mark the option at this stage) ... "not enough space ... DIFFERENT"
now I have the header with the clickable option, so I click it and click "compare" ... "not enough space ... DIFFERENT"

so, same as before. In all fairness, I was using two completely different 5GB files for this test. But it would have helped me to see if the differences start at the first byte or some 10 MB into the files or if there are only a few differences rather than completely different files.

There is no such problem using x64 TC with enough free memory.
I can even compare 60 GB large files.
This takes a long time but works

[Gerdd]

Hmm - just using the 64bit version? I must try that!!!

I still recall reading something that one should never need it as long as 64bit Windows can run 32bit apps. But times they are a'changing ... with 16GB real memory per box I shouldn't have too much trouble with videos that rarely exceed 5 GB in size

(I never would have stumbled across this if I hadn't had a few single bit errors copying across USB controllers (listed as a potential problem elsewhere in this forum - but I believe I nailed it to one particular USB adapter card in one specific machine (back in the days of Windows 7 ...))

That was when I first discovered that the compare option had a size limitation and then discovered the full extent of the usefulness of the Start menu. But that is another story ...

[Horst.Epp]

A 32 Bit program can't have more than 2 GB continues memory without special configs.
It's one of the restrictions which makes it useless to run a 32bit tool on a x64 OS, when you have a x64 version of this tool.

[Gerdd]

I agree, that is exactly what I told my MVS/XA and z/OS users when IBM switched from 24 to 31 and from 31 to 64 bit addressing, but then there are legions of developers that warn you that their "more bits" versions have not been tested very much and the older code was working very well, after all.

Now that 64bit code is seriously mainstream I may need to get off the beaten path and try the no longer untested (?) 64bit code. I repent!

[Dalai]

2Gerdd
There's nothing wrong with continuing to use TC 32-bit - I do the same thing. However, it's a good idea to have TC 64-bit ready to use for tasks like these where memory is a concern or limiting factor. It's also useful for checking bugs, but that certainly doesn't apply to everybody.

NB: There's also nothing wrong with developers being cautious about new platforms. When a platform or architecture is brand new, it can't be tested very much. Bugs and quirks of systems/platforms tend to take time to be discovered and fixed or worked around.

Regards
Dalai

[Gerdd]

Thanks, Dalai! Yes, I recall the days when I lead the way of many users from MVS (24bit) to MVS/XA and later MV/ESA (31bit) as an Assembler developer - but I also took opportunities to coax my users into testing the "above the line" memory usage, just so I could widen the user base and get more environments tested.

As it turns out, now I am just as conservative as some of my users back then

[Horst.Epp]

The usage of x64 OS's and tools is no longer a new world since a long time.
Today, the only reason for a 32bit or combined TC is using some old plugins.

[Gerdd]

Yes, when you think about it ... as a rookie IT user I never would have believed that some day I would be using a phone with a 64bit operating system (and eight processors, no cable and a handful of cameras that would have made photographers of the day weep - plus it doesn't even use film ...))

[ghisler(Author)]

If you need to use 32-bit Total Commander for some old plugins without 64-bit support, you can install the combined 32+64-bit version of Total Commander and then call just the 64-bit version of compare by content, e.g. via a button:
Command: %commander_exe%
Parameters: /S=C %C1 %C2
The parameters %C1 and %C2 behave the same way as when you open the internal compare tool directly: They pass the first 2 selected files to the external tool, or the file under cursor and the same name in the target.

[Horst.Epp]

If you need to use 32-bit Total Commander for some old plugins without 64-bit support, you can install the combined 32+64-bit version of Total Commander and then call just the 64-bit version of compare by content, e.g. via a button:
Command: %commander_exe%
Parameters: /S=C %C1 %C2
The parameters %C1 and %C2 behave the same way as when you open the internal compare tool directly: They pass the first 2 selected files to the external tool, or the file under cursor and the same name in the target.

I use these to start an 32 bit TC and then the normal compare button.
%COMMANDER_PATH%\TOTALCMD.EXE
%Z /N /P %X %P%N* %T%M*