The diff command for files with empty content

Question

If I want to get the difference between the 2 directories, I use the command below:

diff -aruN dir1/ dir2/ > dir.patch

so the dir.patch file should comprise all differences I want, right?

But if dir2/ contains a file with empty content, and that file is not existent in dir1/, for example,

dir1/

dir2/empty_content_file.txt ------ with empty content.

Then the diff command will not generate any patch for empty_content_file.txt, but it is a needed file.

Is there any expertise or alternative way to do this?

Thank you in advance.

rakib_ · Accepted Answer · 2016-06-02 04:41:56Z

1

It's because you're using -N option, which is added to explicitly treat absent file as empty. man diff says :

     -N,  --new-file 
              treat absent file as empty

answered Jun 2, 2016 at 4:41

rakib_

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6 Comments

But the diff command never creates the patch without -N option for inexistent files in dir1/, so -N is necessary...

Well I've tested with or without -N option. Without -N option it does show the existence of a file.

No, no patch is generated without -N argument for inexistent files in the first directory, it shows "Only in dir2/: empty_content_file.txt".

I had uploaded the screenshot of the operations you mentioned.

Okay, I understand your point. You want new file to be added when applying the patch. I believe there's no better option than using git diff.

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David Hsu · Accepted Answer · 2016-06-02 05:36:44Z

0

The screenshot below shows the operation of "diff -aru" command for inexistent files in the first directory, a message "Only in xxx" will show.

answered Jun 2, 2016 at 5:36

David Hsu

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