patch 8.0.0096
Problem: When the input or output is not a tty Vim appears to hang.
Solution: Add the --ttyfail argument. Also add the "ttyin" and "ttyout"
features to be able to check in Vim script.
diff --git a/runtime/doc/starting.txt b/runtime/doc/starting.txt
index 8ce3c63..34500fc 100644
--- a/runtime/doc/starting.txt
+++ b/runtime/doc/starting.txt
@@ -421,6 +421,10 @@
not connected to a terminal. This will avoid the warning and
the two second delay that would happen. {not in Vi}
+ *--ttyfail*
+--ttyfail When the stdin or stdout is not a terminal (tty) then exit
+ right away.
+
*-d*
-d Start in diff mode, like |vimdiff|.
{not in Vi} {not available when compiled without the |+diff|