Is it possible to return the line available in FILE1 but not FILE2 in diff?

[Peng Yu]

Hi,

I just want to return the line available in FILE1 but not FILE2 in
diff. After I read the document, it seems that this is not possible.
Could anybody confirm whether this is true? If so, is there an
alternative tool that does this? Thanks!

--
Regards,
Peng

[Chris F.A. Johnson]

Perhaps you want comm instead of diff:

comm -23 FILE


--
Chris F.A. Johnson <http://cfajohnson.com>
Author: =======================
Pro Bash Programming: Scripting the GNU/Linux Shell (2009, Apress)
Shell Scripting Recipes: A Problem-Solution Approach (2005, Apress)

[Chris F.A. Johnson]

On 2012-11-13, Chris F.A. Johnson wrote:
> On 2012-11-12, Peng Yu wrote:
>> Hi,
>>
>> I just want to return the line available in FILE1 but not FILE2 in
>> diff. After I read the document, it seems that this is not possible.
>> Could anybody confirm whether this is true? If so, is there an
>> alternative tool that does this? Thanks!
>
> Perhaps you want comm instead of diff:
>
> comm -23 FILE

I meant:

comm -23 FILE1 FILE2

[Charles Swiger]

Hi--

On Nov 12, 2012, at 3:19 PM, Peng Yu wrote:
> I just want to return the line available in FILE1 but not FILE2 in
> diff. After I read the document, it seems that this is not possible.
> Could anybody confirm whether this is true? If so, is there an
> alternative tool that does this? Thanks!

Using diff will show removed lines with a "-"; otherwise, consider
using the comm utility since that might be closer to what you want...

% cat > FILE1
This
is
a
test
file.
% tail -4 FILE1 >! FILE2 % diff -bdu FILE1 FILE2
--- FILE1 2012-11-12 16:37:45.000000000 -0800
+++ FILE2 2012-11-12 16:38:11.000000000 -0800
@@ -1,4 +1,3 @@
-This
is
a
test

% comm FILE1 FILE2
This
is
a
test
file.

Regards,
--
-Chuck

[John Cowan]

Charles Swiger scripsit:

> Using diff will show removed lines with a "-";

That's diff -u format.

> using the comm utility since that might be closer to what you want...

That only works if the files are both sorted.

--
Using RELAX NG compact syntax to John Cowan <co...@ccil.org>
develop schemas is one of the simple http://www.ccil.org/~cowan
pleasures in life....
--Jeni Tennison <co...@ccil.org>

[Bob Proulx]

Charles Swiger wrote:
> Peng Yu wrote:
> > I just want to return the line available in FILE1 but not FILE2 in
> > diff. After I read the document, it seems that this is not possible.
> > Could anybody confirm whether this is true? If so, is there an
> > alternative tool that does this? Thanks!
>

> Using diff will show removed lines with a "-"; otherwise, consider

> using the comm utility since that might be closer to what you want...

You might consider that -u may take an optional number of context
lines to display.

`-U LINES'
`--unified[=LINES]'
Use the unified output format, showing LINES (an integer) lines of
context, or three if LINES is not given. *Note Unified Format::.
For proper operation, `patch' typically needs at least two lines of
context.

Allowing use like this:

$ printf "AA\nBB\nCC\n" > 1
$ printf "AA\nCC\n" > 2
$ diff -u 1 2
--- 1 2012-11-13 11:37:56.000000000 -0700
+++ 2 2012-11-13 11:38:03.000000000 -0700
@@ -1,3 +1,2 @@
AA
-BB
CC
$ diff -u0 1 2 | sed "1,2d;/^@@/d"
-BB
$ diff -u0 1 2 | sed "1,2d;/^@@/d;s/^-//"
BB

Bob