How to Import Environment Settings into My Perl Program

How do I import environment settings into my Perl program?

#!/bin/sh
. /myfolder1/myfolder2/myScript.sh
exec perl -wxS "$0" "$@"
#!/usr/bin/perl -w
# .. the rest of your script as normal

When you run this, it will first be executed by /bin/sh, which is capable of loading myScript.sh into the local environment. sh then execs Perl, which is told to continue from the following line.

Importing environment variables to Perl

If you want Bash to export a variable into the environment so it's accessible to programs, you can use the export builtin:

export PRDIR

Inside Perl, you would then access it using the %ENV hash:

my $varex = $ENV{"PRDIR"};
print "\$varex is: $varex\n";

How can I properly import the environment from running a subcommand in Perl?

I am assuming that the environment variables after program has executed are not same as the environment passed to it (which you can find in %ENV as explained in jeje's answer.

I am by no means knowledgeable about bash, so I am only going to address the part of the question about parsing the output of env.

#!/usr/bin/perl

use strict;
use warnings;

use autodie qw( open close );

$ENV{WACKO} = "test\nstring\nwith\nnewlines\n\n";

my %SUBENV;

open my $env_h, '-|', 'env';

my $var;

while ( my $line = <$env_h> ) {
    chomp $line;
    if ( my ($this_var, $this_val) = $line =~ /^([^=]+)=(.+)$/ ) {
        if ( $this_val =~ /^\Q()\E/ ) {
            $var = q{};
            next;
        }
        $var = $this_var;
        $SUBENV{ $var } = $this_val;
    }
    elsif ( $var ) {
        $SUBENV{ $var } .= "\n$line";
    }
}

use Data::Dumper;
print Dumper \%SUBENV;

Importing environment variables set by batch file in parent Perl script

If your BAT file is simple (i.e. it only contains lines of the form VAR=VALUE), you can parse it by Perl. If there is something more going on (some values are calculated from others etc.), just output all the variable names and their values at the end of the BAT script in the form VAR=VALUE.

The parsing of the simple format is easy:

while (<$BAT>) {
    chomp;
    my ($var, $val) = split /=/, $_, 2;
    $ENV{$var} = $val;
}

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