![]() Most of the actual Getopt::Long code is not loaded until you really call one of its functions. This will load the core of the Getopt::Long module and prepare your program for using it. To use Getopt::Long from a Perl program, you must include the following line in your Perl program: use Getopt::Long This module also supports single-character options and bundling. This was the first Perl module that provided support for handling the new style of command line options, in particular long option names, hence the Perl5 name Getopt::Long. The form is now obsolete and strongly deprecated. Also, option values could be specified either like -size=24 Early implementations of long options used a plus instead. To distinguish between a bundle of single-character options and a long one, two dashes are used to precede the option name. So instead of a cryptic -l one could use the more descriptive -long. Sometimes with whitespace in between, sometimes not: -s 24 -s24ĭue to the very cryptic nature of these options, another style was developed that used long names. Options can have values, the value is placed after the option character. Usually, these single-character options can be bundled: -lac Historically, they are preceded by a single dash -, and consist of a single letter. For example, a program could do its job quietly, but with a suitable option it could provide verbose information about what it did.Ĭommand line options come in several flavours. Options are not necessary for the program to work, hence the name 'option', but are used to modify its default behaviour. Besides arguments, these programs often take command line options as well. # Command Line Options, an IntroductionĬommand line operated programs traditionally take their arguments from the command line, for example filenames or other information that the program needs to know. Support for bundling of command line options, as was the case with the more traditional single-letter approach, is provided but not enabled by default. In general, this means that options have long names instead of single letters, and are introduced with a double dash "-". This function adheres to the POSIX syntax for command line options, with GNU extensions. It parses the command line from recognizing and removing specified options and their possible values. The Getopt::Long module implements an extended getopt function called GetOptions(). Or die("Error in command line arguments\n") #DESCRIPTION ![]() GetOptions ("length=i" => \$length, # numeric Getopt::Long - Extended processing of command line options #SYNOPSIS use Getopt::Long ![]() How do I put a "-?" option into a Getopt::Long?.Undefined subroutine
0 Comments
Leave a Reply. |