programming-examples/perl/SystemFunction/Extract command-line switches with Getopt-Std.pl
2019-11-15 12:59:38 +01:00

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758 B
Perl

use Getopt::Std;
Getopt::Std::getopts( 'a:b:de' );
This call sets up five command-line switches: a, b, d, and e.
The colons after a, b tell getopts that a, b require values.
d, and e are called Boolean switches.
Boolean switches are either set or not.
For example, the following sets a Boolean switch:
command -d
The following sets a switch with a value:
command -a value
With the Getopt::Std module, the getopts routine sets variables starting with opt_ for each option that is set. For example, the -a switch corresponds to the $opt_a variable. Thus, you can use the following code to look for a -a switch:
use Getopt::Std;
Getopt::Std::getopts( 'a' );
if ( defined( $opt_a ) ) {
print "-a flag set to $opt_a\n";
}