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Handling command line options - getopt
Topicalization and Special Variables example from a Well House Consultants training course
More on Topicalization and Special Variables [link]
=head1 Handling command line options with getopts
The getopts sub (in the Getopt::std module that's
supplied with the Perl distribution) lets you process
command line parameters (from @ARGV) ... filtering out
options into flag variables without the need for you
to write (and maintain) that code yourself.
=cut
use Getopt::Std;
print "Raw parameters: @ARGV\n";
#-------- Handle incoming option
# In this example, our command may be run with
# -v -h and -i options (which will get set into
# variable $opt_v, etc)
$status = getopts('vhi');
if ($status) {
print "I am happy\n";
} else {
# Error message and exit
# $0 is the program name
die "$0: I am sad\n";
}
#-------- End of option handling
#------- MUST have a file name -----
die ("$0: file name misd\n") unless(@ARGV);
$opt_i and print("Interactive\n");
$opt_h and print("Ha, ha! No help!\n");
$opt_v and print("Verbose mode selected\n");
print "Cooked parameters: @ARGV\n";
__END__
Sample output:
Dorothy:p82 grahamellis$ perl gop
Raw parameters:
I am happy
gop: file name misd
Dorothy:p82 grahamellis$ perl gop -iv course.perl book.perl
Raw parameters: -iv course.perl book.perl
I am happy
Interactive
Verbose mode selected
Cooked parameters: course.perl book.perl
Dorothy:p82 grahamellis$ perl gop -ivf course.perl book.perl
Raw parameters: -ivf course.perl book.perl
Unknown option: f
gop: I am sad
Dorothy:p82 grahamellis$
More on Topicalization and Special Variables [link]
|
This example is described in the following article(s): • Seven new intermediate Perl examples - [link] |
Source code: gop2 Module: P210
=head1 Handling command line options with getopts
The getopts sub (in the Getopt::std module that's
supplied with the Perl distribution) lets you process
command line parameters (from @ARGV) ... filtering out
options into flag variables without the need for you
to write (and maintain) that code yourself.
=cut
use Getopt::Std;
print "Raw parameters: @ARGV\n";
#-------- Handle incoming option
# In this example, our command may be run with
# -v -h and -i options (which will get set into
# variable $opt_v, etc)
$status = getopts('vhi');
if ($status) {
print "I am happy\n";
} else {
# Error message and exit
# $0 is the program name
die "$0: I am sad\n";
}
#-------- End of option handling
#------- MUST have a file name -----
die ("$0: file name misd\n") unless(@ARGV);
$opt_i and print("Interactive\n");
$opt_h and print("Ha, ha! No help!\n");
$opt_v and print("Verbose mode selected\n");
print "Cooked parameters: @ARGV\n";
__END__
Sample output:
Dorothy:p82 grahamellis$ perl gop
Raw parameters:
I am happy
gop: file name misd
Dorothy:p82 grahamellis$ perl gop -iv course.perl book.perl
Raw parameters: -iv course.perl book.perl
I am happy
Interactive
Verbose mode selected
Cooked parameters: course.perl book.perl
Dorothy:p82 grahamellis$ perl gop -ivf course.perl book.perl
Raw parameters: -ivf course.perl book.perl
Unknown option: f
gop: I am sad
Dorothy:p82 grahamellis$
Learn about this subject
This module and example are covered on the following public courses:
* Perl Programming
* Perl bootcamp
* Learning to program in Perl
* Perl Programming
Also available on on site courses for larger groups
* Perl Programming
* Perl bootcamp
* Learning to program in Perl
* Perl Programming
Also available on on site courses for larger groups
Books covering this topic
Yes. We have over 700 books in our library. Books
covering Perl are listed here and when you've selected a
relevant book we'll link you on to Amazon to order.
Other Examples
This example comes from our "Topicalization and Special Variables" training module. You'll find a description of the topic and some
other closely related examples on the "Topicalization and Special Variables" module index page.
Full description of the source code
The complete training module that describes this source code
is availble for download (for limited use) from
our download centre.
Other resources
• Our Solutions centre provides a number of longer technical articles.
• Our Opentalk forum archive provides a question and answer centre.
• The Horse's mouth provides a daily tip or thought.
• Further resources are available via the resources centre.
• All of these resources can be searched through through our search engine
• And there's a global index here.
• Our Opentalk forum archive provides a question and answer centre.
• The Horse's mouth provides a daily tip or thought.
• Further resources are available via the resources centre.
• All of these resources can be searched through through our search engine
• And there's a global index here.
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This program is copyright Well House Consultants Ltd. You are forbidden from using it for running your own training courses without our prior written permission. See our page on courseware provision for more details.
Any of our images within this code may NOT be reused on a public URL without our prior permission. For Bona Fide personal use, we will often grant you permission provided that you provide a link back. Commercial use on a website will incur a license fee for each image used - details on request.
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