1 files changed, 38 insertions, 0 deletions
diff --git a/sys/fio/frmbfs.x b/sys/fio/frmbfs.x
new file mode 100644
index 00000000..ec1df5e7
--- /dev/null
+++ b/sys/fio/frmbfs.x
@@ -0,0 +1,38 @@
+# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+
+include	<config.h>
+include	<fio.h>
+
+# FRMBFS -- Return file buffer.  Called by FSET to change the buffer size,
+# and by FRTNFD when a file is closed.
+
+procedure frmbfs (fd)
+
+int	fd			# file descriptor
+
+long	offset
+errchk	mfree, flush
+include	<fio.com>
+
+begin
+	fp = fiodes[fd]
+	if (bufptr[fd] == NULL)
+	    return
+	else
+	    call fcanpb (fd)
+
+	# Note file offset, return buffer and initialize i/o pointers,
+	# restore seek offset (which depends on buffer pointer, buf offset).
+
+	offset = LNOTE(fd)
+	call mfree (bufptr[fd], TY_CHAR)
+	call mfree (FPBBUF(fp), TY_CHAR)
+
+	bufptr[fd] = NULL
+	boffset[fd] = NULL
+	buftop[fd] = NULL
+	itop[fd] = NULL
+	otop[fd] = NULL
+
+	LSEEK (fd, offset)
+end