+$opt{units} = [split //, ' kMGTPEZYyzafpn'.($opt{ascii} ? 'u' : 'μ').'m']
+ if $opt{'human-readable'};
+$opt{anchor} //= qr/\A/;
+$opt{'value-length'} = 6 if $opt{units};
+$opt{'value-length'} = 1 if $opt{unmodified};
+$opt{'signal-stat'} //= exists $SIG{INFO} ? 'INFO' : 'QUIT';
+$opt{markers} //= '=avg >31.73v <68.27v +50v |0';
+$opt{palette} //= $opt{color} && [31, 90, 32];
+$opt{indicators} = [split //, $opt{indicators} ||
+ ($opt{ascii} ? ' .oO' : $opt{spark} ? ' ▁▂▃▄▅▆▇█' : ' ▏▎▍▌▋▊▉█')
+] if defined $opt{indicators} or $opt{spark};
+$opt{hidemin} = ($opt{hidemin} || 1) - 1;
+$opt{input} = (@ARGV && $ARGV[0] =~ m/\A[-0-9]/) ? \@ARGV : undef
+ and undef $opt{interval};
+
+$opt{'sum-format'} = sub { sprintf '%.8g', $_[0] };
+$opt{'calc-format'} = sub { sprintf '%*.*f', 0, 2, $_[0] };
+$opt{'value-format'} = $opt{units} && sub {
+ my $unit = (
+ log(abs $_[0] || 1) / log(10)
+ - 3 * (abs($_[0]) < .9995) # shift to smaller unit if below 1
+ + 1e-15 # float imprecision
+ );
+ my $decimal = ($unit % 3) == ($unit < 0);
+ $unit -= log($decimal ? .995 : .9995) / log(10); # rounded
+ $decimal = ($unit % 3) == ($unit < 0);
+ $decimal &&= $_[0] !~ /^-?0*[0-9]{1,3}$/; # integer 0..999
+ sprintf('%*.*f%1s',
+ 3 + ($_[0] < 0), # digits plus optional negative sign
+ $decimal, # tenths
+ $_[0] / 1000 ** int($unit/3), # number
+ $#{$opt{units}} * 1.5 < abs $unit ? sprintf('e%d', $unit) :
+ $opt{units}->[$unit/3] # suffix
+ );
+};
+
+
+my (@lines, @values, @order);
+
+$SIG{$_} = \&show_stat for $opt{'signal-stat'} || ();
+$SIG{ALRM} = sub {
+ show_lines();
+ alarm $opt{interval} if defined $opt{interval} and $opt{interval} > 0;
+};
+$SIG{INT} = \&show_exit;