调用安装在不同路径/目录中的 Perl 模块 [英] Calling a Perl Module which is Installed in different path/directory

问题描述

我正在编写一个 Perl 脚本 -

I am writing a Perl script which does -

• SSH 到其中一台服务器并使用 Net::OpenSSH Perl 模块执行一些操作.
• 我希望使用 Log::Log4perl Perl 模块将脚本的整个日志存储在某个日志文件中.
• 我想使用 Text::CSV Perl 模块将一些数据写入 CSV 文件.

• SSH to one of the server and do some operation using Net::OpenSSH Perl Module.
• I want to have entire log of the script to be stored in certain log file using Log::Log4perl Perl Module.
• I want to write some data to CSV file using Text::CSV Perl Module.

实际上这三个 Perl Module 已经安装在不同的目录中.

Actually these three Perl Modules have been installed in different directories.

让我们说 -

• Net::OpenSSH 安装在/path/to/lib1
• Log::Log4perl 安装在/path/to/lib2
• Text::CSV 安装在/path/to/lib3

• Net::OpenSSH is installed in /path/to/lib1
• Log::Log4perl is installed in /path/to/lib2
• Text::CSV is installed in /path/to/lib3

由于这些 Perl 模块已经安装在不同的位置，我在 Shebang 行中提到了各自的路径，如下所示:

Since these Perl Modules has been installed in different locations, I am mentioning the respective paths in Shebang line like below:

方法一:

#!/usr/bin/perl -I/path/to/lib1 -I/path/to/lib2 -I/path/to/lib3

use strict;
use warnings;

use Net::OpenSSH;
use Log::Log4perl;
use Text::CSV;

#continue flow of the script
..

这对我来说非常好.

我找到了另一种调用这些 Perl 模块的方法，如下所示:

I found one more method to call these Perl modules like below:

方法二:

#!/usr/bin/perl

use strict;
use warnings;

use lib '/path/to/lib1';
use lib '/path/to/lib2';
use lib '/path/to/lib3';
...

以上方法对我来说也很好用.

Above method also works fine for me.

我通过使用 FindBin 找到了调用这些 Perl 模块的标准方法.

I found the standard way to call these Perl modules by the use of FindBin.

我对它的语法感到困惑.我如何使用 FindBin Perl 模块实现相同的目标.

I am confused with its syntax. How can I achieve same using FindBin Perl Module.

方法 3:

#!/usr/bin/perl

use strict;
use warnings;

use FindBin qw($Bin);
use lib "$Bin/path/to/lib1";
use lib "$Bin/path/to/lib2";
use lib "$Bin/path/to/lib3";
...

这会引发以下错误，当我使用前两种方法(方法 1、方法 2)时不会出现该错误.

This throws me following error which doesn't appears when I use first two methods (Method1, Method2).

unable to load Perl module IO::Pty: Can't locate IO/Pty.pm in @INC ...

我在方法 3 中哪里做错了?

Where I am doing wrong in Method 3?

推荐答案

$RealBin 是脚本所在的目录.($Bin 是同一事物的损坏版本.)

$RealBin is the directory in which the script is located. ($Bin is a broken version of the same thing.)

如果脚本所在的目录和模块所在的目录没有关系，那么使用$RealBin是没有意义的.事实上，在这种情况下，使用 PERL5LIB env var 比 use lib 通常更有意义.

If there's no relationship between the directory in which the script is located and the directory in which a module is located, it doesn't make sense to use $RealBin. In fact, it usually makes more sense to use the PERL5LIB env var than use lib in such cases.

另一方面，如果脚本位于 /path/to/bin，则使用相对于 $RealBin 的路径可能是有意义的.

On the other hand, if the script was located in /path/to/bin, it might make sense to use a path relative to $RealBin.

use lib                 # In /path/to/bin/script,
   "$RealBin/../lib1",  #    This is /path/to/bin/../lib1, or /path/to/lib1
   "$RealBin/../lib2",  #    This is /path/to/bin/../lib2, or /path/to/lib2
   "$RealBin/../lib3";  #    This is /path/to/bin/../lib3, or /path/to/lib3

$RealBin 通常在脚本和模块打包在一起(同一项目的一部分)时使用.use lib 也一样，真的.

$RealBin is usually used when the script and modules are packaged together (part of the same project). Same for use lib, really.

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