ExamDiff Pro FAQ :: ExamDiff Pro :: Home

Answers to Frequently Asked Questions

Technical Questions:

  1. How do I start ExamDiff Pro from Windows Explorer?
  2. How do I start ExamDiff Pro from Total (formerly Windows) Commander?
  3. Why can't I edit files, and why are Delete Block and Add/Replace Block menu items disabled?
  4. What comparison algorithm does ExamDiff Pro use?
  5. Why does ExamDiff Pro's menu have white boxes around text?
  6. Are there limits to the sizes of input files?
  7. When I copy a directory (with a file), it still does not refresh like it does when I copy just a file. Why?
  8. Timestamps of copied files are 1-2 seconds ahead of their sources. Why?
  9. Can I compare two text fragments without files?
  10. Sometimes very long lines are not fully visible in Windows 95/98/Me. Why?
  11. How can I make comparison faster?
  12. How can I compare files on the Internet?
  13. How can integrate ExamDiff Pro with WinCVS?
  14. Is there a way to integrate ExamDiff Pro with SourceSafe?
  15. How do the "Ignore blank lines" and "Ignore lines matching regular expression" options work?
  16. Is there a way to turn on address columns in binary comparison panes?
  17. Why are almost identical files shown as completely different?
  18. Why are ExamDiff Pro menu items not visible when I right-click on a file in Windows Explorer?
  19. Why is a comparison plug-in producing no output or giving strange results when applied to clipboard contents?
  20. Can I migrate all ExamDiff Pro options from one computer to another?
  21. What can I do if ExamDiff Pro window has gone off screen?

Ordering and Licensing Questions:

  1. Where can I purchase ExamDiff Pro?
  2. How much does ExamDiff Pro cost?
  3. Can I purchase ExamDiff Pro with a purchase order?
  4. Can I purchase ExamDiff Pro by phone?
  5. How is ExamDiff Pro delivered? How long is its delivery time?
  6. Are there any delivery charges or processing fees for ExamDiff Pro?
  7. Is ExamDiff Pro a controlled product? What is its Export Control Classification Number (ECCN)?
  8. Will my license expire?
  9. How many users can use one ExamDiff Pro license? How many machines can it be installed on?
  10. I lost my license ... What do I do?
  11. Am I eligible for a free upgrade? How do I do it?
  12. How do I purchase an upgrade license?
  13. What operating systems can ExamDiff Pro run on?
  14. What languages does ExamDiff Pro support?
  15. Do you have any authorized resellers?
  16. I wish to purchase ExamDiff Pro licenses on behalf of someone else. How do I do this?
  17. Why does ExamDiff Pro show the evaluation dialog box after I copied my password file?
  18. Why are some of the features disabled even after I register the software?

Technical Questions

1. How do I start ExamDiff Pro from Windows Explorer?

Version 3.2c or above includes full Shell integration that allows you to select two files or directories in Windows Explorer, right-click on them and select compare from the menu. Alternatively, you can select one file or directory and choose it as the first item to compare, then select another file or directory and compare it with the fist item.

For versions 3.1 or earlier you need to add a shortcut to ExamDiff Pro to your Send To folder. Now you can simply select two files or directories, right-click and send to ExamDiff Pro.

2. How do I start ExamDiff Pro from Total (formerly Windows) Commander?

To compare files with IDENTICAL names in two panes:
Add a new button from the menu: Configuration > Button bar...
A new button setting will be added to the default.bar file:

button11=E:\ExamDiff\ExamDiff.exe
cmd11=E:\ExamDiff\ExamDiff.exe
param11=%p%n %t%n
path11=E:\ExamDiff\
menu11=Compare Files

Submitted by Daniel Liu

To compare files with DIFFERENT names in two panes:
Same as the above except for the following:

param11=%p%n %t%m

Submitted by Anders Borup

3. Why can't I edit files, and why are Delete Block and Add/Replace Block menu items disabled?

  • Your evaluation license has expired
  • View filter is used
  • Word Wrap mode is on
  • "Enable editing within ExamDiff Pro" option is off (you can turn it on in Options | File Editing)
  • Block in source file is not a part of a file but rather an empty space inserted by ExamDiff to synchronize file views
  • The files are out-of-sync due to manual addition or deletion of lines in either file (this only disables block operations; re-compare and try again)
  • Binary files in Hex comparison mode are not editable

4. What comparison algorithm does ExamDiff Pro use?

The diff algorithm ExamDiff Pro uses is based on Eugene Myers' algorithm that uses "longest common subsequences" to figure out the shortest diff script (see Myers' paper in PDF or PostScript format).

5. Why does ExamDiff Pro's menu have white boxes around text?

This happens in Windows XP after customizing a theme. Note that many Windows applications exhibit this behavior, including Notepad, Calculator, Paint, etc. For information on how to fix the menu white box problem please refer to this article.

6. Are there limits to the sizes of input files?

There are no limits imposed by the software. The limits are set by your memory and CPU speed. (For example, we were able to compare two registry dumps 100 MBytes each.) However, it may take a long time to compare huge files, especially if they have many differences.

7. When I copy a directory (with a file), it still does not refresh like it does when I copy just a file. Why?

Here's the problem: ExamDiff Pro uses Windows Explorer Shell API to do file operations such as copy. Unfortunately, there is no reliable way to figure out if a file operation was successful, especially when multiple items are copied (i.e. ExamDiff Pro doesn't know if the user pressed No or even Cancel; on one of the Explorer warning dialogs). For files ExamDiff Pro just checks if a certain file was really copied, i.e. that a target file's size and time match the ones of a source file. For directories this approach doesn't generally work. (It works if there are no selected subdirectories in the target directory, but it doesn't work if both source and target subdirectories existed before the copying). If the option Compare subdirectories only to determine their status is selected, the program can only advise a user to re-compare (changing the re-compare toolbar button) -- and again, it can only be a guess, since ExamDiff Pro doesn't know whether the subdirectories were really copied.

8. Timestamps of copied files are 1-2 seconds ahead of their sources. Why?

It seems to be a known problem that when you copy files to a Win95/98/Me system (especially from WinNT/2000/XP), the new files may be 1-2 seconds ahead since Win95/98/Me has a file time granularity of 2 seconds whereas NT/2000/XP with FAT has a granularity of 1 second, and NT/2000/XP with NTFS has a granularity of 100 nanoseconds. By the way, since all file operations in ExamDiff Pro are done by delegating them to the Windows Explorer Shell, you'll get the same results by using Windows Explorer to copy files.

9. Can I compare two text fragments without files?

Version 3.3 or above allows you to select clipboard contents instead of one or both files in the Compare dialog.

For version 3.2c or earlier open ExamDiff Pro without selecting files, then paste your text fragments to both of file panes and click Re-Compare.

10. Sometimes very long lines are not fully visible in Windows 98/Me. Why?

ExamDiff Pro uses the Win32 ExtTextOut API to draw lines, and Win95 and its successors use 16-bit GDI subsystem, which is, unlike NT/2000, unable to draw lines longer than 8192. ExamDiff Pro limits line lengths to 8192 characters, and after that it will require you to use word wrap. Apparently, 8192 is sometimes too long for ExtTextOut. The limit could be lowered but that would make NT/2000 users suffer for no reason. One user reported that reducing the font size makes long lines fully visible.

11. How can I make comparison faster?

Try these methods to speed up comparison of large text files:
  • Do not use Ignore settings in Options | Compare (or use View | Ignore the ignores).
  • Set Detail level... to Lines in Options | Compare.
  • Disable Fuzzy matching in Options | Compare | Advanced.
Large binary file comparison can be sped up by increasing the Comparison block size in Options | Binary.

These methods will speed up comparison of large directories:
  • Uncheck the Perform full file comparison option and check some of the options below it in Options | Dir Comparison.
  • Check the For faster comparison options in Options | Dir Comparison.
  • Use name and date/size filters in Options | Dir Comparison | Filters.
  • Uncheck the Process reparse points for subdirectories option in Options | Dir Comparison | Other.

12. How can I compare files on the Internet?

Version 3.5 or higher includes plug-ins that allow you to compare remote files and folders simply by inputting their URLs.

If you have version 3.4, you can manually set up the Fetch Remote File and Fetch Remote Directory plug-ins.

For earlier versions, you can use Web Folders. Web Folders support HTTP (through WebDAV) and FTP protocols, and will work with any Windows version as long as you have Internet Explorer 5 or higher installed. Check Windows Help on Web Folders.

13. How can I integrate ExamDiff Pro with WinCVS?

Go to the Admin | Preferences | WinCVS Tab, enable the External diff program option, and browse to your copy of the ExamDiff Pro executable. When you use the Diff command from WinCVS, don't forget to check the Use the external diff option in the Diff settings tab.

14. Is there a way to integrate ExamDiff Pro with SourceSafe?

SourceSafe 6.0 does not allow users to replace the diff utility they use - it appears to be a part of the SourceSafe executable ssexp.exe.

SourceSafe 2005 permits replacing its diff tool: go to Tools | Options | Custom Editors, then select the File Difference operation for the .* File Extension and specify the path to ExamDiff Pro followed by %1 %2 in the Command Line field, then click Add and OK.

One other useful tool is this convenient SourceSafe shell extension by David Y. Zhao. All you need to do is install and configure it, and then use ExamDiff Pro's Explorer Menu on right click in comparison panes.

15. How do the "Ignore blank lines" and "Ignore lines matching regular expression" options work?

Starting with version 3.3, if the Ignore blank lines and Ignore lines matching regular expression options are used, ExamDiff Pro does not include such lines in comparison (pretending that they don't exist).

Prior to version 3.3, these options caused ExamDiff Pro to ignore changes whose lines were all blank or matched a specified regular expression. In other words, ExamDiff Pro ignored modified blocks only if ALL lines in a block (which may be a block of added, deleted or changed lines) were blank or matched the regular expression.

16. Is there a way to turn on address columns in binary comparison panes?

No. And the reason is padding: in order for the files to be aligned, empty spaces are added. Thus there cannot be consistent byte numbering for both files. However if you click anywhere in a binary pane, the status bar will show the current offset.

17. Why are almost identical files shown as completely different?

Prior to version 4.5, ExamDiff Pro could only synchronize identical lines: it did not perform fuzzy comparison where, for example, 90% identical lines could be considered identical, and thus be synchronized. A common result of this is that files that are nearly the same are displayed as almost completely different. Sometimes the problem could be resolved by turning on Ignore options,Ignore all white space in lines being the top candidate. Starting with version 3.5 this problem could also be resolved by adding manual synchronization links.

Starting with version 4.5, ExamDiff Pro can perform fuzzy matching to resolve this issue. You can enable Fuzzy matching in Options | Compare | Advanced.

18. Why are ExamDiff Pro menu items not visible when I right-click on a file in Windows Explorer?

Sometimes ExamDiff Pro's Windows Explorer context menu is not properly registered during installation. First, make sure that the Enable Windows Explorer (Shell) integration option is checked in Options | Global. If it is, uncheck this option and press OK. Then go back to Options | Global, check Enable Windows Explorer (Shell) integration, and press OK.

19. Why is a comparison plug-in producing no output or giving strange results when applied to clipboard contents?

The problem probably lies in the fact that ExamDiff Pro saves temporary Unicode files when plug-ins are executed on Clipboard contents, and the plug-in you used is unable to handle Unicode files. (All plug-ins on the ExamDiff Pro plug-in page are able to correctly handle Unicode files.)

If you have a plug-in that doesn't support Unicode, one solution, suggested by a user, is to create a batch file with these contents:

@echo off
PATH=<path>
iconv.exe -f UTF-16 -t MS-ANSI %1 | <plug-in>


where <path> is the path to the directory where your plug-in is, <plug-in> is the plug-in with any necessary command-line parameters, and iconv.exe is an iconv implementation (such as GNU libiconv), stored in the same directory as the plug-in.

Then simply use this batch file in place of the original plug-in in ExamDiff Pro when you need to apply it to clipboard contents.

20. Can I migrate all ExamDiff Pro settings from one computer to another?

If you only need to migrate your options (comparison settings, color, etc.), simply use the Export/Import buttons on the Options dialog.

To migrate all ExamDiff Pro settings, including its visual elements (layouts, toolbars) and sessions with their options, you need to export the following Registry key: HKEY_CURRENT_USER\Software\PrestoSoft\ExamDiff Pro. Use Microsoft Registry Editor (regedit.exe) to export this key on the source computer, and to later import the resulting registration file on the target computer.

Version 7.0 or higher includes Export/Import Settings commands.

21. What can I do if ExamDiff Pro window has gone off screen?

Highlight ExamDiff Pro in the task bar, hit Alt + Space, then M (alternatively, use Shift + Right-Click), then press any arrow key. You can now move the hidden window with your mouse until it appears on your screen.

Ordering and Licensing Questions

1. Where can I purchase ExamDiff Pro?

A wide variety of secure purchase options is offered at ExamDiff Pro's purchase page.

2. How much does ExamDiff Pro cost?

For information about ExamDiff Pro's price, see the ExamDiff Pro pricing page. Multi-license discounts are applied to all orders for more than one license, and educational discounts are available to students and educators.

3. Can I purchase ExamDiff Pro with a purchase order?

Sure. See our PO page for information on how to buy ExamDiff Pro with a purchase order.

4. Can I purchase ExamDiff Pro by phone?

The payment processor SWREG will allow you to order via phone, for a nominal fee.

5. How is ExamDiff Pro delivered? How long is its delivery time?

Delivery is electronic and automatic. The software is downloaded here, and your password is emailed to you as soon as credit card charges are cleared. We do not ship ExamDiff Pro on physical media.

6. Are there any delivery charges or processing fees for ExamDiff Pro?

No.

7. Is ExamDiff Pro a controlled product? What is its Export Control Classification Number (ECCN)?

ExamDiff Pro is not a controlled product. The ECCN for our products is EAR99 (not on the Commerce Control List).

8. Will my license expire?

No, your license will never expire. You'll always be able to use your license with ExamDiff Pro versions you are eligible for, i.e. all versions released within one year from the time of your purchase (or longer if you purchased a longer maintenance period). You will not be forced to upgrade just because a new version is available.

9. How many users can use one ExamDiff Pro license? How many machines can it be installed on?

Each purchased license grants the right for ExamDiff Pro to be used either by a single person who uses the software personally on one or more computers, or installed on a single PC used nonsimultaneously by multiple people, but not both. Each license also includes unlimited email support and one year or more of free upgrades (depending on the number of maintenance years purchased).

10. I lost my license ... What do I do?

If you lost your license, simply send an email to PrestoSoft with as much of the following information as you can give us: your registration name, your purchase date, and the email address you used to register ExamDiff Pro. The more information that you give us the better the chance that we can recover your password.

11. Am I eligible for a free upgrade? How do I do it?

Your ExamDiff Pro license enables you to use any version of ExamDiff Pro released up to a year after your purchase. To get a newer version of ExamDiff Pro that you are eligible to use, simply go to our download page.

12. How do I purchase an upgrade license?

If you wish to use a version of ExamDiff Pro released more than a year after you purchased your last license, you need to purchase an upgrade license. To order an upgrade, please send an email to PrestoSoft with your current registration name and number of licenses you own (you can find this information in the About Box). In return you will be emailed instructions on how to purchase an upgrade. If you purchased ExamDiff Pro more than once, and you wish to upgrade all of your separate licenses in one consolidated upgrade, please email all of your registration names along with the number of licenses for each registration.

13. What operating systems can ExamDiff Pro run on?

The latest version of ExamDiff Pro supports Windows XP, 2003, Vista, 7, 2008, 8, 2012, 8.1, both 32- and 64-bit. It has been reported that ExamDiff Pro can be run reasonably well on Unix/Linux/Mac OS X systems using Wine.

14. What languages does ExamDiff Pro support?

At present, we offer ExamDiff Pro only in English. A Japanese version is available from our partner SolitonWave.

15. Do you have any authorized resellers?

We don't use resellers. All our e-commerce providers can be found on the ExamDiff Pro purchase page.

16. I wish to purchase ExamDiff Pro licenses on behalf of someone else. How do I do this?

To purchase ExamDiff Pro licenses on behalf of someone else, simply enter their name as the Registration Name during the purchase process, and either include your client's email address on the purchase form or use your email address and then forward to your client the password email you receive after the purchase.

17. Why does ExamDiff Pro show the evaluation dialog box after I copied my password file?

This is usually due to one (or both) of the following reasons:
  1. Your password file was generated for a different version of ExamDiff Pro.
  2. You used the right file but put it in a wrong directory. Please make sure that your ExamDiff Pro shortcut points to the same directory where the password.bin file is located.

18. Why are some of the features disabled even after I register the software?

When the 30-day evaluation period ends, certain advanced features of ExamDiff Pro become disabled, and for some of these features it is done by resetting the program options. After registration these options do not become automatically enabled (after all, they may be disabled by a user for any reason). This is why, if you want to get all of the advanced features restored after the registration, you need to go to ExamDiff Pro Options and enable the following:
  • Set detail mode to words or characters (Options | Compare)
  • Ignore lines matching regular expression (Options | Compare)
  • Ignore parts of each line (Options | Compare)
  • Ignore comments (Options | Ignore comments | Ignore comments)
  • Use word wrap (Options | Word Wrap)
  • Perform recursive directory comparison (Options | Dir Comparison)
  • Edit files within ExamDiff Pro (Options | File Editing)
  • Use plug-ins (Options | Plug-ins)
  • Use Windows Explorer (Shell) integration (Options | Global)