1 files changed, 51 insertions, 0 deletions
diff --git a/unix/os/zfxdir.c b/unix/os/zfxdir.c
new file mode 100644
index 00000000..af3373f9
--- /dev/null
+++ b/unix/os/zfxdir.c
@@ -0,0 +1,51 @@
+/* Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+ */
+
+#include <stdio.h>
+#include <ctype.h>
+#define import_spp
+#define	import_kernel
+#define import_knames
+#include <iraf.h>
+
+/* ZFXDIR -- Extract OS directory prefix from OSFN.  The null string is
+ * returned if there is no directory prefix.  The status value is the number
+ * of characters in the output string.
+ */
+int
+ZFXDIR (
+  XCHAR	 *osfn,			/* OS filename		[NOT PACKED]	*/
+  XCHAR	 *osdir, 		/* receives osdir	[NOT PACKED]	*/
+  XINT	 *maxch, 
+  XINT   *nchars
+)
+{
+	register XCHAR	*ip, *op;
+	register int	n = *maxch;
+	XCHAR	*last_slash;
+
+
+	for (ip=osfn;  *ip == ' ';  ip++)
+	    ;
+
+	/* A UNIX pathname must begin with a / (anything else is considered an
+	 * IRAF pathname).  The OSDIR part includes everything up to the
+	 * rightmost /.  A string of the form "/name" has the directory prefix
+	 * "/", i.e. "name" is considered a filename not a subdirectory name.
+	 */
+	last_slash = NULL;
+	op = osdir;
+
+	if (*ip == '/')
+	    for (;  --n >= 0 && (*op = *ip++);  op++)
+		if (*op == '/')
+		    last_slash = op;
+
+	if (last_slash != NULL)
+	    op = last_slash + 1;
+
+	*op = XEOS;
+	*nchars = op - osdir;
+
+	return (XOK);
+}