避免重新定义已定义函数的 Perl 库

Question

我有两个 perl 模块文件，例如:

is_date_holiday.pl :

use strict;
use warnings;
sub IsDateHoliday
{
   ...
}
1

calc_prev_working_date_mult.pl :

use strict;
use warnings;
require "is_date_holiday.pl"; # IsDateHoliday
sub CalcPrevWorkingDateMult 
{
   ...
}
1

关于在 perl 文件中同时使用它们，例如:

require "is_date_holiday.pl"; # IsDateHoliday
require "calc_prev_working_date_mult.pl" # CalcPrevWorkingDateMult

它提示我正在重新定义函数 IsDateHoliday

如何做相当于#ifndef 的操作？

Answer 1

你实际上没有modules ，但你应该这样做。

IsDateHoliday.pm:

package IsDateHoliday;

use strict;
use warnings;

use Exporter qw( import );
our @EXPORT_OK = qw( IsDateHoliday );
our %EXPORT_TAGS = ( all => \@EXPORT_OK );

sub IsDateHoliday
{
   ...
}

1;

CalcPrevWorkingDateMult.pm:

package CalcPrevWorkingDateMult;

use strict;
use warnings;

use Exporter qw( import );
our @EXPORT_OK = qw( CalcPrevWorkingDateMult );
our %EXPORT_TAGS = ( all => \@EXPORT_OK );

use IsDateHoliday qw( :all );

sub CalcPrevWorkingDateMult
{
   ...
}

1;

main.pl:

use IsDateHoliday           qw( :all );
use CalcPrevWorkingDateMult qw( :all );