[Gnuplot-info] how to send user-defined variables to linux commands

[Jon <dev...@gm...>]

Dear All,

I would like to define a variable and then use it in the linux command
within a gnuplot script, how to successfully do that? An example is
provided below

==========================
set macro
pos=2
tgt="`ls ../../.. | head -n pos | tail -n 1`"
set term pngcairo transparent color solid
set out @tgt.'_file.png'
p sin(x)
set out
==========================

note pos is the variable I would like to define in the script to be used in
the linux command

ls ../../.. | head -n pos | tail -n 1

but it cannot be sent over. Is there way to realize the like functionality
within gnuplot?

Thanks,

Sincerely,
Jon