+if grep '[[bB]]roken pipe' stderr >/dev/null 2>&1; then
+ # Something in the environment caused SIGPIPE to be ignored, but
+ # 'yes' at least told us that it got EPIPE. Good enough; we know
+ # that stdout was closed.
+ :
+else
+ # Otherwise make sure that 'yes' died from SIGPIPE.
+ AT_CHECK([kill -l `cat status`], [0], [PIPE