1 files changed, 33 insertions, 0 deletions
diff --git a/sys/etc/psioxfer.x b/sys/etc/psioxfer.x
new file mode 100644
index 00000000..ca286512
--- /dev/null
+++ b/sys/etc/psioxfer.x
@@ -0,0 +1,33 @@
+# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
+
+define	SZ_NUMBUF	8		# encoded count for an XFER
+
+
+# PSIO_XFER -- Transfer a data record to a process to complete an XFER
+# request.  Write the byte count record followed by the data record.
+# These must be written as two separate records or deadlock
+# will occur (with the reader waiting for the second record).
+
+procedure psio_xfer (fd, buf, nchars)
+
+int	fd			# output file
+char	buf[ARB]		# buffer containing record to be written
+int	nchars			# length of record
+
+int	ndigits
+char	numbuf[SZ_NUMBUF]
+int	itoc()
+
+begin
+	if (nchars >= 0) {
+	    ndigits = itoc (nchars, numbuf, SZ_NUMBUF)
+	    numbuf[ndigits+1] = '\n'
+	    call write (fd, numbuf, ndigits + 1)
+	    call flush (fd)
+
+	    if (nchars > 0) {
+		call write (fd, buf, nchars)
+		call flush (fd)
+	    }
+	}
+end