GNU bug report logs - #16329
`head --lines=-0' prints nothing if no newline at the EOF

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Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: Алексей Шилин <rootlexx <at> mail.ru>
To: bug-coreutils <at> gnu.org
Subject: `head --lines=-0' prints nothing if no newline at the EOF
Date: Fri, 03 Jan 2014 19:50:56 +0400

[Message part 1 (text/plain, inline)]

Hi,

If one runs `head --lines=-0 somefile', he'll sometimes get no output instead of full file contents as
expected after reading the manual:

-n, --lines=[-]K
        print the first K lines instead of the first 10; with the lead‐
        ing `-', print all but the last K lines of each file

It depends on whether the file has a trailing newline.

For example:

$ printf '1\n2\n3' > test1
$ printf '4\n5\n' > test2
$ head -n -0 test*
==> test1 <==

==> test2 <==
4
5
$ tail -n +0 test*   # Just for comparison
==> test1 <==
1
2
3
==> test2 <==
4
5
$ 

I'm using Debian GNU/Linux 7 wheezy and coreutils-8.13; I've also tested coreutils-8.22, and it has the
same issue.

A proposed patch fixing the bug is attached. It makes head behave exactly like `tail -n +0' on same files.

-- 
Алексей Шилин

[head_nlines_fix.patch (application/x-patch, attachment)]

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