Re: "diff -R" to swap file1 and file2?

[Chris Jones]

On Wed, Feb 02, 2011 at 06:59:55AM EST, Harald Dunkel wrote:
> Hi folks,
> 
> would it be possible to add a flag "-R" or "--reverse" 
> to the diff command line options to swap left and right 
> side file on the fly? 
> 
> If you made a mistake on writing the diff command line, 
> then adding a "-R" would be much easier and less error-
> prone than moving one of the pathnames within the command 
> line. 
> 
> This option would be pretty similar to "patch -R".
> 
> Just a suggestion, of course. Regards

Makes sense.. in the meantime, with bash+readline, this is how I do it:

1. I retrieve my command:

   CTRL-P

   $ diff file.file1 file.file2

2. I delete/yank the second file name:

   CTRL-W

   Result.. with ‘^’ marking the cursor's position:

   $ diff file.file1 
                     ^
3. I move the cursor to the first character of file #1:

   ALT-B ALT-B

   Results in:

   $ diff file.file1 
          ^

4. I paste the second file name:

   CTRL-Y

   Now it looks like so:

   $ diff file.file2file.file1
                    ^

5. And finally... I press the Space Bar & hit <Enter>:

   $ diff file.file2 file.file1

Takes less than a second (and about five minutes to put in words) .. and
since I'm only yanking & pasting, not error-prone.. :-)

cj