in reply to hmm - - - something has changed in perl (from 5.34 to 5.36

I'm getting the same error in 5.26. What works is to use -B4 (i.e. no space).


$before = shift @ARGV assigns the first element of @ARGV to $before. The first element is -B, regardless of the Perl version. Also, changing the array you're currently iterating over doesn't seem to be a safe operation.

How to fix?

Iterate over the indices rather than elements if you want to peek into surrounding elements.
my $before; my $arg_index = 0; while ($arg_index < $#ARGV) { my $arg = $ARGV[$arg_index]; if( $arg =~ /^-B(\d+)$/ ) { # months Before $before = $1; } elsif( $arg =~ /^-B$/ ) { $before = $ARGV[++$arg_index]; if( $before !~ /^\d+/ ) { die "Bad before argument ($before)\n"; } } } continue { ++$arg_index; }

Note that the code doesn't report "Bad before" if there's no space after -B but the value is not a number.

How to fix properly?

Use Getopt::Long.

map{substr$_->[0],$_->[1]||0,1}[\*||{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^*ARGV,3]