How to diff two file lists and ignoring place in list

Question

I have two lists of files which I want to diff. The second list has more files in it, and because they are all in alphabetical order when I diff these two lists I get files (lines) that exists in both lists, but in a different place.

I want to diff these two lists, ignoring line place in the list. This way I would get only the new or missing lines in the list.

Thank you.

Answer 1

If the lines are sorted, diff should catch the insertions and deletions just fine and only report the differences.

Answer 2

Sorting the two list before you diff them will provide a more useful diff data.

Answer 3

For the example you quotes @Sparr

a contains

a.txt
b.txt
c.txt

b contains

a.txt
a1.txt
b.txt
b2.txt

diff a b gives

1a2
> a1.txt
3c4
< c.txt
---
> b2.txt

What is it about this output that does not meet your needs?

Answer 4

You can try this approach which involves "subtracting" the two lists as follows:

$ cat file1
a.txt
b.txt
c.txt

$ cat file2
a.txt
a1.txt
b.txt
b2.txt

1) print everything in file2 that is not in file1 i.e. file2 - file1

$ grep -vxFf file1 file2
a1.txt
b2.txt

2) print everything in file1 that is not in file2 i.e. file1 - file2

$ grep -vxFf file2 file1
c.txt

(You can then do what you want with these diffs e.g. write to file, sort etc)

grep options descriptions:

  -v, --invert-match        select non-matching lines
  -x, --line-regexp         force PATTERN to match only whole lines
  -F, --fixed-strings       PATTERN is a set of newline-separated strings
  -f, --file=FILE           obtain PATTERN from FILE

Answer 5

Do the following:

cat file1 file2 | sort | uniq -u

This will give you a list of files which are uniq (ie, not duplicated).

Explanation:
1) cat file1 file2 will put all of the entries into one list
2) sort will sort the combined list
3) uniq -u will only output the entries which don't have duplicates