cat essaiQX.pl
#!/usr/bin/perl 

my $LANG = "script internal";

system('echo $LANG');
system('echo','$LANG');

my @out = qx "echo $LANG";
chomp(@out);
print "out=@out\n";

my @out = qx' echo $LANG ';
chomp(@out);
print "out=@out\n";