Say explicitly that eq is useful for chars; xref number comparison, lispref 2008-05-27 Aidan Kehoe <kehoea@parhasard.net> * lispref/objects.texi (Equality Predicates): Cross reference to the section on comparison of numbers when talking about using #'eq with integers; also mention that #'eq gives t when passed identical integers, and that #'char= is also available there.

#!/bin/sh
if
test -r $2
then
if
cmp $1 $2 > /dev/null
then
echo $2 is unchanged
rm -f $1
else
mv -f $1 $2
fi
else
mv -f $1 $2
fi