http://www.perlmonks.org?node_id=996986


in reply to Range in Getopt

You can evaluate options with Getopt::Long using a custom subroutine, like this: 


use Getopt::Long;
my $_debug;
GetOptions('d=i' => sub {
        $_debug = $_[1];
        ($_debug > 0 && $_debug <= 4) or die "Invalid Debug Level ($_d
+ebug)"
    } ) and warn $_debug;

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GetOptions catches the die and throws it as a warning and returns false. When using the custom subroutine, you need to handle assigning to the variable for your option yourself.

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Re^2: Range in Getopt
by roho (Bishop) on Oct 03, 2012 at 13:26 UTC
    I like your solution, but when no -d parameter is present, the following warning is displayed:

    Warning: something's wrong at C:\tmp\getopt-range.pl line 15.

    This appears to be a warning from Getopt::Long. I tried adding return 1 if !defined @_; at the top of the sub but the warning persists.

    "Its not how hard you work, its how much you get done."

[reply]
      That is because while the d option's value is required, the d option itself is not, check the definedness of $_debug afterwards: 

      use Getopt::Long;
my $_debug;
GetOptions('d=i' => sub {
        $_debug = $_[1];
        ($_debug > 0 && $_debug <= 4) or die "Invalid Debug Level ($_d
+ebug)"
    } ) or exit 1;

die "Debug Level is required" unless defined $_debug;
warn "Debug Level is $_debug\n";

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      or set a default value before GetOptions: 

      use Getopt::Long;
my $_debug = 0;
GetOptions('d=i' => sub {
        $_debug = $_[1];
        ($_debug > 0 && $_debug <= 4) or die "Invalid Debug Level ($_d
+ebug)"
    } ) or exit 1;

warn "Debug Level is $_debug\n";

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