if test for empty and non-existing file

Shell Programming and Scripting
1

How to write this condition in ksh?

if myfile is empty or myfile does not exist
then
do action1
fi

is this OK?

if [[ -s "$myfile" ]] -o [[ -f "$myfile" ]] then
then
do action1
fi

Thanks.

2 
if [[ -s "$myfile" -o -f "$myfile" ]] ; then
#do action1
fi

Look at man test.

vino

3

Actually this did not work on HP-UX
However replacing the -o with || works

[[ cond1 || cond2 ]]

why is ksh so strange???

4

From man ksh

       [[ expression ]]
              Similar to the test and [ ... ] commands (described later), with
              the following exceptions:
                o    Field splitting and file name  generation  are  not  per-
                     formed on arguments.
                o    The  -a  (and) and -o (or) operators are replaced with &&
                     and ||, respectively.