# use strict;     # UPDATE: that was commented as spotted by Eily ( see below)
    # use warnings;   # UPDATE

    BEGIN{print "inside BEGIN  \@ARGV is [@ARGV]\n"}

    my $test='original value';

    print       "inside main   \@ARGV is [@ARGV] and \$test is [$test]\n";

##</code><code>##

    perl -s simple.pl -test=SET_VIA_-s arg1
    inside BEGIN  @ARGV is [arg1] and $test is [SET_VIA_-s]
    inside main   @ARGV is [arg1] and $test is [original value]

##</code><code>##

    perl -MO=Deparse -s simple.pl -test=SET_VIA_-s arg1
    inside BEGIN  @ARGV is [arg1] and $test is [SET_VIA_-s]
    sub BEGIN {
    print "inside BEGIN  \@ARGV is [@ARGV] and \$test is [$test]\n";
    }
    my $test = 'original value';
    print "inside main   \@ARGV is [@ARGV] and \$test is [$test]\n";
    simple.pl syntax OK

##</code><code>##

    perl -se "BEGIN{print qq(inside BEGIN  \@ARGV is [@ARGV]\n)};print qq(inside main   \@ARGV is [@ARGV] and \$test is [$test]\n);"  
            -test=SET_VIA_-s arg1

    inside BEGIN  @ARGV is [arg1]
    Can't modify constant item in scalar assignment at -e line 2, near "SET_VIA_-s"
    syntax error at -e line 2, near "SET_VIA_-s"
    Execution of -e aborted due to compilation errors.

##</code><code>##

    perl -se "BEGIN{print qq(inside BEGIN  \@ARGV is [@ARGV]\n)};print qq(inside main   \@ARGV is [@ARGV] and \$test is [$test]\n);" 
             -- -test=SET_VIA_-s arg1

    inside BEGIN  @ARGV is [arg1]
    inside main   @ARGV is [arg1] and $test is [SET_VIA_-s]

##</code><code>##

    perl -se "use strict; use warnings;BEGIN{print qq(inside BEGIN  \@ARGV is [@ARGV]\n)}my $test='originalvalue';print qq(inside main   \@ARGV is [@ARGV] and \$test is [$test]\n);" 
         -- -test=SET_VIA_-s arg1

    inside BEGIN  @ARGV is [arg1]
    inside main   @ARGV is [arg1] and $test is [original value]

##</code><code>##

    perl -se "'A'=~/(A)/;print $1      " -- -1=OUCH!
    OUCH!

    perl -se "'A'=~/(A)/;print qq($1\n)" -- -1=OUCH!
    A