how to write script usage sub routine for the perl file?

perlanswers has asked for the wisdom of the Perl Monks concerning the following question:

How can i write the usage function to run the file in perl.

./html.pl -root="/home/data/multiple/" -out="/home/data/output" -file=
+"/home/data/file.txt"
[download]

I have the above perl file.I have to run the same file in the terminal as i mentioned above.How can i include usage of the script inside the perl file.
code which i have tried

use strict;
use warnings;
use Getopt::Long qw(GetOptions);
sub usage {
   if (@_) {
      my ($msg) = @_;
      chomp($msg);
      print(STDERR "$msg\n");
   }

GetOptions(
       'root=s' => \my $dir,
    'out=s' => \my $out,
    'file=s' => \my $file,
)
    or usage();
[download]

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Re: how to write script usage sub routine for the perl file? the dynamic duo with Pod::Usage by Discipulus (Canon) on Apr 03, 2017 at 07:54 UTC
Hello perlanswers and welcome to the monastery and to wonderful world of Perl! There are many way to do it but I found the following particulary useful and versatile: The Dynamic Duo --or-- Holy Getopt::Long, Pod::UsageMan! Infact Pod::Usage can semplfy a lot such part of a program: it can shows sections of your choice of the `POD` embed in the program (I'm used to put the POD after the `__DATA__` token), it has the ability to modify the exit value with the useful `NOEXIT` feature. The module can semplify a lot the `help` and `manual` commandline options; let's see it's recommendend usage: `use strict; use Pod::Usage; use Getopt::Long; ## Parse options my %opt; GetOptions(\%opt, "help\|?", "man", "flag1") \|\| pod2usage(2); pod2usage(1) if ($opt{help}); pod2usage(-exitval => 0, -verbose => 2) if ($opt{man}); ## Check for too many filenames pod2usage("$0: Too many files given.\n") if (@ARGV > 1);` [download] L* There are no rules, there are no thumbs.. Reinvent the wheel, then learn The Wheel; may be one day you reinvent one of THE WHEELS.	[reply] [d/l] [select]
Re: how to write script usage sub routine for the perl file? by huck (Prior) on Apr 03, 2017 at 06:35 UTC
Friend of yours? Re^2: How to read the input directory from command line arguments using perl?	[reply]
Re^2: how to write script usage sub routine for the perl file? by marto (Cardinal) on Apr 03, 2017 at 08:27 UTC
Looks like the same person.	[reply]
Re^3: how to write script usage sub routine for the perl file? by LanX (Saint) on Apr 03, 2017 at 09:18 UTC
Yes! Cheers Rolf _{(addicted to the Perl Programming Language and ☆☆☆☆ :) Je suis Charlie!}	[reply]
Re: how to write script usage sub routine for the perl file? by Anonymous Monk on Apr 03, 2017 at 05:52 UTC
From looking at the code, the usage function expects an argument. But, none is given. `... or usage();` [download]	[reply] [d/l]
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