1 files changed, 66 insertions, 0 deletions
diff --git a/libX11/src/DisName.c b/libX11/src/DisName.c
new file mode 100644
index 000000000..59b5b3e1f
--- /dev/null
+++ b/libX11/src/DisName.c
@@ -0,0 +1,66 @@
+/* $Xorg: DisName.c,v 1.4 2001/02/09 02:03:32 xorgcvs Exp $ */
+
+/*
+
+Copyright 1994, 1998  The Open Group
+
+Permission to use, copy, modify, distribute, and sell this software and its
+documentation for any purpose is hereby granted without fee, provided that
+the above copyright notice appear in all copies and that both that
+copyright notice and this permission notice appear in supporting
+documentation.
+
+The above copyright notice and this permission notice shall be included
+in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR
+OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+OTHER DEALINGS IN THE SOFTWARE.
+
+Except as contained in this notice, the name of The Open Group shall
+not be used in advertising or otherwise to promote the sale, use or
+other dealings in this Software without prior written authorization
+from The Open Group.
+
+*/
+/* $XFree86$ */
+
+/* XDisplayName.c */
+/* 
+ * Returns the name of the display XOpenDisplay would use.  This is better
+ * than just printing the "display" variable in a program because that
+ * could be NULL and/or there could be an environment variable set.
+ * This makes it easier for programmers to provide meaningful error
+ * messages. 
+ *
+ * 
+ * For example, this is used in XOpenDisplay() as
+ *	strncpy( displaybuf, XDisplayName( display ), sizeof(displaybuf) );
+ *      if ( *displaybuf == '\0' ) return( NULL );
+ *  This check is actually unnecessary because the next thing is an index()
+ *  call looking for a ':' which will fail and we'll return(NULL).
+ */
+/* Written at Waterloo - JMSellens */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+#include <stdio.h>
+#include <stdlib.h>
+#include "Xlib.h"
+
+char *
+XDisplayName(
+    _Xconst char *display)
+{
+    char *d;
+    if ( display != (char *)NULL && *display != '\0' )
+	return( (char *)display );
+    if ( (d = getenv( "DISPLAY" )) != (char *)NULL )
+	return( d );
+    return( "" );
+}