1 files changed, 51 insertions, 0 deletions
diff --git a/refer/shell.c b/refer/shell.c
new file mode 100644
index 0000000000000..3dbc9f41aa988
--- /dev/null
+++ b/refer/shell.c
@@ -0,0 +1,51 @@
+/*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
+/*	  All Rights Reserved  	*/
+
+
+/*
+ * Copyright (c) 1980 Regents of the University of California.
+ * All rights reserved. The Berkeley software License Agreement
+ * specifies the terms and conditions for redistribution.
+ */
+
+/*
+ * Copyright (c) 1983, 1984 1985, 1986, 1987, 1988, Sun Microsystems, Inc.
+ * All Rights Reserved.
+ */
+
+/*	from OpenSolaris "shell.c	1.3	05/06/02 SMI" 	*/
+
+/*
+ * Portions Copyright (c) 2005 Gunnar Ritter, Freiburg i. Br., Germany
+ *
+ * Sccsid @(#)shell.c	1.4 (gritter) 12/25/06
+ */
+
+/*
+ * SORTS UP.
+ * IF THERE ARE NO EXCHANGES (IEX=0) ON A SWEEP
+ * THE COMPARISON GAP (IGAP) IS HALVED FOR THE NEXT SWEEP
+ */
+void
+shell (int n, int (*comp)(int, int), int (*exch)(int, int))
+{
+	int igap, iplusg, iex, i, imax;
+	igap=n;
+	while (igap > 1)
+	{
+		igap /= 2;
+		imax = n-igap;
+		do
+		    {
+			iex=0;
+			for(i=0; i<imax; i++)
+			{
+				iplusg = i + igap;
+				if ((*comp) (i, iplusg) ) continue;
+				(*exch) (i, iplusg);
+				iex=1;
+			}
+		} 
+		while (iex>0);
+	}
+}