msg /StartBE        (#  &#9492;żj</
(more or less, the └ in the code tags was replaced by its HTML equivalent, &#9492;)

Not very useful in determining what the pack function is trying to do. It looks like line noise, so did the pack fail? Is the format wrong? I dunno.

But I'll also mention that pack and unpack still confuse me, even though I know the surrounding Perl syntax in that function. And even after reading most of perldoc -f pack and perldoc perlpacktut.

You had asked

can you please Tell what $msg Returns here.

My point is that you could have found out for yourself what was being returned. Anything else (what does pack/unpack do) is a separate question.

Minor note, I'm not the person who originally asked.

Another note, koti688 did specifically ask "I want to know what pack and Unpack do excatly" [sic]. Although I will admit that I missed the second question the first time I read it. But in any case, it's pretty clear from the printed output that someone unfamiliar with pack/unpack isn't going to gain much from looking at the output.