Way to output differences between two files (preferably using command line)

Question

I am familiar with tools such as tkDiff and WinMerge and am aware of how to see the difference between two files.

What I'm looking to do is to produce a report of elements in one file that are not present in another.

For example:

File1 contains:

apple cool dude flan 

File2 contains:

apple ball cool dude elephant 

I want to produce a report that contains:

ball elephant 

Or, better yet, a report like this:

+ball +elephant -flan 

Does anybody know of a tool that can do this? Preferably with command line options.

The report feature in WinMerge isn't too far off what I'd like but there is no command line option to do this (as far as I know).

Thanks in advance.

Answer 1

This might work for you (GNU diff):

diff -u file1 file2 | sed -n '1,2d;/^[-+]/p' +ball -flan +elephant 

Answer 2

You probably want the Unix comm utility. Windows versions are included in gnuwin32

NAME

   comm - compare two sorted files line by line 

SYNOPSIS

   comm [OPTION]... FILE1 FILE2 

DESCRIPTION

   Compare sorted files FILE1 and FILE2 line by line.     With  no    options,  produce  three-column  output.  Column one contains    lines unique to FILE1, column two contains lines unique to  FILE2,  and    column three contains lines common to both files.     -1     suppress lines unique to FILE1     -2     suppress lines unique to FILE2     -3     suppress lines that appear in both files