head,tail: add the -z,--zero-terminated option

* doc/coreutils.texi: Reference the option description.
* src/head.c: Parameterize the delimiter character.
* src/tail.c: Likewise.
* tests/misc/head.pl: Add test case.
* tests/misc/tail.pl: Likewise.
* NEWS: Mention the new feature.

1 files changed, 4 insertions, 0 deletions

diff --git a/tests/misc/tail.pl b/tests/misc/tail.pl
index c23102fe8..0d9bc4834 100755
--- a/tests/misc/tail.pl
+++ b/tests/misc/tail.pl
@@ -101,6 +101,10 @@ my @tv = (
 
 # With textutils-1.22, this failed.
 ['f-pipe-1', '-f -n 1', "a\nb\n", "b\n", 0],
+
+# --zero-terminated
+['zero-1', '-z -n 1', "x\0y", "y", 0],
+['zero-2', '-z -n 2', "x\0y", "x\0y", 0],
 );
 
 my @Tests;