perl Getopt::Long::GetOptions usage

3
votes

I wanted to use Getopt::Long::GetOptions for getting command line options to the script.

I have a requirement like this:

perl script.pl -c <name1> -c <name2> -m <name3> argument

Here we have option flags -c and -mm which are optional, and argument is mandatory.

Can anyone point out the correct usage for GetOptions?

2
shellperlcommand-line-tool

2 Answers

4
votes

From the Getopt::Long documentation:

GetOptions does not return a false result when an option is not supplied

That's why they're called 'options'.

In other words, if you are expecting a mandatory parameter, you need to explicitly check for it outside of the GetOptions call.

If argument is meant to be part of @ARGV and not the options, use -- to signal the end of options. In the example below, the script would access argument via $ARGV[0]:

perl script.pl -c <name1> -c <name2> -m <name3> -- argument
1
votes

Here's a sample code and result.

https://gist.github.com/kyanny/5634832

If you want to know more about how to handle multiple values option, see documantation: http://perldoc.perl.org/Getopt/Long.html#Options-with-multiple-values

One more thing, Getopt::Long::GetOptions does not provide the way to handle mandatory options. You should check if the mandatory options are in the @ARGV and raise Exceptions, etc. in your hand.