Set a shell array from an array in Perl script

Question

I have the following Perl script:

 sub {
    my $sequence=\"SEQUENCE1\";
    my $sequence2=\"SEQUENCE2\";
    my @Array = ($sequence, $sequence2);
    return \\@         


        

Answer 1

Did you test your Perl script? In order to have that Perl script give you something to put into your shell script, you to make sure your Perl script works:

$ test.pl

No output at all.

First issue, you put the whole Perl script in sub. Subroutines in Perl don't execute unless you call them. You can't even do that since your subroutine doesn't even have a name. Let's get rid of the subroutine:

my $sequence="SEQUENCE1";
my $sequence2="SEQUENCE2";
my @Array = ($sequence, $sequence2);
print  \@Array . "\n";

Okay, now let's try the program:

$ test.pl   
ARRAY(0x7f8bab8303e0)

You're printing out an array reference with that \ in the front of @Array. Let's print out the array itself:

my $sequence="SEQUENCE1";
my $sequence2="SEQUENCE2";
my @Array = ($sequence, $sequence2);
print  @Array, "\n";

That will now print @Array:

$ test.pl
SEQUENCE1SEQUENCE2

Not quite. There's no spaces between each element. Let's set $, which is the output field separator to be a single space:

my $sequence="SEQUENCE1";
my $sequence2="SEQUENCE2";
my @Array = ($sequence, $sequence2);
$,=' ';
print @Array, "\n";

Now:

$ test.pl
SEQUENCE1 SEQUENCE2

Now, we have a working Perl program that outputs what we need to put into your shell array:

seq=($(test.pl))
echo ${seq[*]}
SEQUENCE1 SEQUENCE2

When you have an issue, you need to break it down into pieces. Your first issue is that your Perl script wasn't working. Once that was fixed, you could now use it to initialize your array in your Bash shell.