如何在Perl中复制符号链接？

Question

如何在保留所有符号链接属性（例如所有者和权限）的同时复制Perl程序中的符号链接（而不是它指向的文件）？

Answer 1

In Perl you can use the readlink() function to find out the destination of a symlink.

You can also use the lstat() function to read the permissions of the symlink (as opposed to stat() which will read the details of the file pointed to by the symlink).

Actually setting the ownership on the new symlink can't be done without extra help as Perl doesn't expose the lchown() system call. For that you can use the Perl Lchown module from CPAN.

Assuming sufficient permissions (nb: unchecked code)

 use Lchown;
 my $old_link = 'path to the symlink';
 my $new_link = 'path to the copy';

 my $dst = readlink($old_link);
 my @stat = lstat($old_link);

 symlink $dst, $new_link;
 lchown $stat[4], $stat[5], $new_link;  # set UID and GID from the lstat() results

You don't need to worry about the permissions on the symlink - they always appear as -rwxrwxrwx

Answer 2

The module File::Copy::Recursive takes care of that. By default it will copy symlinks and try to preserve ownership.

Answer 3

Depending on your use case regarding absolute vs. relative target paths, dir hierarchy etc., using link to create a hardlink to the symlink you want to copy might be enough already as well. No extra packages needed and creating hardlinks is supported by Perl on many platforms as well.