various: general adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

No functional change intended.

1 files changed, 6 insertions, 1 deletions

diff --git a/usr.bin/at/parsetime.h b/usr.bin/at/parsetime.h
index 30c3f207aa3d..c3201645b081 100644
--- a/usr.bin/at/parsetime.h
+++ b/usr.bin/at/parsetime.h
@@ -1,5 +1,8 @@
-/* 
+/*-
  *  at.h -  header for at(1)
+ *
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
  *  Copyright (C) 1993  Thomas Koenig
  *
  * Redistribution and use in source and binary forms, with or without
@@ -21,6 +24,8 @@
  * THEORY OF LIABILITY, WETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * $FreeBSD$
  */
 
 time_t parsetime(int argc, char **argv);