在 Perl 中，如何确定我的文件是作为模块使用还是作为脚本运行? [英] In Perl, how can I find out if my file is being used as a module or run as a script?

问题描述

假设我有一个 Perl 文件，其中只有当我作为脚本调用时才需要运行的部分.我记得有一段时间读过关于将这些部分包含在 main() 方法中并执行

Let's say I have a Perl file in which there are parts I need to run only when I'm called as a script. I remember reading sometime back about including those parts in a main() method and doing a

main() unless(<some condition which tests if I'm being used as a module>);

但我忘记了条件是什么.搜索谷歌并没有产生任何结果.有人可以指出寻找这个的正确位置吗?

But I forgot what the condition was. Searching Google hasn't turned out anything fruitful. Can someone point out the right place to look for this?

推荐答案

如果将文件作为脚本调用，将不会出现 调用者 所以你可以使用:

If the file is invoked as a script, there will be no caller so you can use:

main() unless caller;

请参阅 brian d foy 的 说明.

#!/usr/bin/perl

use strict;
use warnings;

main() unless caller;

sub main {
    my $obj = MyClass->new;
    $obj->hello;
}

package MyClass;

use strict;
use warnings;

sub new { bless {} => shift };

sub hello { print "Hello World
" }

no warnings 'void';
"MyClass"

输出:

C:Temp> perl MyClass.pm
Hello World

从另一个脚本使用:

C:Temp> cat mytest.pl
#!/usr/bin/perl

use strict;
use warnings;

use MyClass;

my $obj = MyClass->new;
$obj->hello;

输出:

C:Temp> mytest.pl
Hello World

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