core: Add which.

* core/which/which.spec: New file.

core/which/which.spec

@@ -0,0 +1,25 @@
+Name:           which
+Version:        2.23
+Release:        0
+Summary:        Displays where a particular program in your path is located
+License:        GPL-3.0-or-later
+Group:          System/Base
+URL:            https://savannah.gnu.org/projects/which/
+Source0:        https://ftpmirror.gnu.org/gnu/%{name}/%{name}-%{version}.tar.gz
+Source1:        https://ftpmirror.gnu.org/gnu/%{name}/%{name}-%{version}.tar.gz.sig
+Source2:        https://savannah.gnu.org/people/viewgpg.php?user_id=3639#/%{name}.keyring
+Provides:       util-linux:%{_bindir}/which
+BuildSystem:    autotools
+
+%description
+The which command shows the full pathname of a specified program, if the
+specified program is in your PATH.
+
+%files
+%license COPYING
+%doc EXAMPLES README README.alias AUTHORS NEWS
+%{_bindir}/which
+%{_infodir}/which.info%{?ext_info}
+%{_mandir}/man1/which.1%{?ext_man}
+
+%changelog