In Perl, how can I append a regex match with output from an external command in a substation?

Let's say I have a list of IPs that looks like this:

10.2.3.4

10.5.3.2

10.5.3.1

...

I know about the 'e' option in regex, which does an eval against the replacement string. I just wanted to do a straight up replacement, I could do this:

s/(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})/`{$1}dig -x $1 +short`/ge;   

But, what I really want to do is append the host name to regex match like this:

10.2.3.4    website.example.com开发者_开发技巧

10.5.3.2    dc01.example.com

10.5.3.1    dc02.example.com

...

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If you all you need to do is append, you don't need a regex at all. Just do:

chomp($_ .= '  ' . qx(dig -x $_ +short)) for @list;

I'm not sure what the {$1} is for in your example, though.

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Try this, it works for me:

s/(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})/"$1 ". `dig -x $1 +short`/ge;

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s/(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})/$1.`{$1}dig -x $1 +short`/ge;