在我的例子中，perl中的继承显示了一个错误

我有两个perl模块，一个是e.pm，两个是.pm，还有一个是perl脚本

 package one;
sub foo
{
 print "this is one\n";
}
sub goo
{
 print "This is two\n";
}
1;

下午两点

package two;
use one;
@ISA=(one);
sub hoo
{
  print "this is three \n";
}
1;

inherit.pl

use two;
foo();

当我执行inherit.pl时，我得到以下错误

 Undefined subroutine &main::foo called at inherit.pl line 2.

---

遗产与此无关。您没有导出任何内容，因此

foo

子例程不在脚本的命名空间中

事实上，您还混合了面向对象的概念（继承）和经典的Perl模块。如果您有一个非oop模块，您可以使用exporter并将Sub引入脚本。如果您有一个类，则可以从另一个类继承。但是，您通常不会导出任何内容

现在，如果您想使用

two

从

one

导入一些东西，基本上构建一些类似于公共函数集合的东西，那么您需要在

one

中使用Exporter，然后在

two

中使用one，然后在

two

中使用Exporter导出从

one

导入的函数

---

听起来很复杂？是的，因为它很复杂。这样做并没有真正的好处，除非在脚本中保存一行

使用一行
。
继承对对象有效。您试图做的是导入，而不是继承。我在下面概述了继承和导入的示例

继承：

One.pm
：

package One;

sub foo {
    print "this is one\n";
}
1;

package Two;

# Note the use of 'use base ...;'. That means that we'll inherit 
# all functions from the package we're calling it on. We can override
# any inherited methods by re-defining them if we need/want

use base 'One';

sub new {
    return bless {}, shift;
}
1;

package One;

use Exporter qw(import);
our @EXPORT_OK = qw(foo); # allow user to import the 'foo' function if desired

sub foo {
    print "this is one\n";
}
1;

package Two;
use One qw(foo); # import foo() from One

use Exporter qw(import);
our @EXPORT_OK = qw(foo); # re-export it so users of Two can import it

1;

Two.pm
：

package One;

sub foo {
    print "this is one\n";
}
1;

package Two;

# Note the use of 'use base ...;'. That means that we'll inherit 
# all functions from the package we're calling it on. We can override
# any inherited methods by re-defining them if we need/want

use base 'One';

sub new {
    return bless {}, shift;
}
1;

package One;

use Exporter qw(import);
our @EXPORT_OK = qw(foo); # allow user to import the 'foo' function if desired

sub foo {
    print "this is one\n";
}
1;

package Two;
use One qw(foo); # import foo() from One

use Exporter qw(import);
our @EXPORT_OK = qw(foo); # re-export it so users of Two can import it

1;

inherit.pl
：

use warnings;
use strict;

use Two;

my $obj = Two->new;
$obj->foo;

use warnings;
use strict;

use Two qw(foo);

foo();

进口：

One.pm
：

package One;

sub foo {
    print "this is one\n";
}
1;

package Two;

# Note the use of 'use base ...;'. That means that we'll inherit 
# all functions from the package we're calling it on. We can override
# any inherited methods by re-defining them if we need/want

use base 'One';

sub new {
    return bless {}, shift;
}
1;

package One;

use Exporter qw(import);
our @EXPORT_OK = qw(foo); # allow user to import the 'foo' function if desired

sub foo {
    print "this is one\n";
}
1;

package Two;
use One qw(foo); # import foo() from One

use Exporter qw(import);
our @EXPORT_OK = qw(foo); # re-export it so users of Two can import it

1;

Two.pm
：

package One;

sub foo {
    print "this is one\n";
}
1;

package Two;

# Note the use of 'use base ...;'. That means that we'll inherit 
# all functions from the package we're calling it on. We can override
# any inherited methods by re-defining them if we need/want

use base 'One';

sub new {
    return bless {}, shift;
}
1;

package One;

use Exporter qw(import);
our @EXPORT_OK = qw(foo); # allow user to import the 'foo' function if desired

sub foo {
    print "this is one\n";
}
1;

package Two;
use One qw(foo); # import foo() from One

use Exporter qw(import);
our @EXPORT_OK = qw(foo); # re-export it so users of Two can import it

1;

import.pl
：

use warnings;
use strict;

use Two;

my $obj = Two->new;
$obj->foo;

use warnings;
use strict;

use Two qw(foo);

foo();

请注意，在下一个Perl版本（5.26.0）中，
@INC
默认情况下将不包括当前工作目录，因此要
使用一个或
使用两个如果这些模块文件位于本地目录中，则必须添加
use lib'或
unshift@INC'或类似内容。
可能重复@dubes我不同意该评估。感谢您解释继承和导入