Ideally I could suppress informational messages but keep the warning
messages, per the traditional unix > and 2> output routings for
sysout and syserr. But texexec does not appear to make the
distinction.

$>texexec --pdf --batch mytest.tex &>/dev/null

Routing all output to /dev/null is a trick that I use sometimes, but
if the run errors off then it just hangs with no message.

for errors
$>egrep '^\!' mytest.log

and for figures
$> egrep 'figure.*can not be found' mytest.log