From: WATANABE Hirofumi <eban@...>
Date: 2005-03-21T15:04:25+09:00
Subject: Re: equivalent idiom for ruby " perl -pe 's/(\d+)/localtime($1)/e'"

Hi,

Jason Sweat <jason.sweat@gmail.com> writes:

> I see that
> 
>  ruby -pe '$_.gsub!(/^(\d+)/, Time.at($1.to_i).to_s)' /var/log/squid/access.log
> 
> works as well.

$1 becomes a result of the match last time, beause $1 is
evaluated before gsub! is called.

% ruby -e '1111111111.upto(1111111115){|i| puts i}' |\
  ruby -pe '$_.gsub!(/^(\d+)/, Time.at($1.to_i).to_s)'
Thu Jan 01 09:00:00 JST 1970
Fri Mar 18 10:58:31 JST 2005
Fri Mar 18 10:58:32 JST 2005
Fri Mar 18 10:58:33 JST 2005
Fri Mar 18 10:58:34 JST 2005

So you should use a block.

% ruby -e '1111111111.upto(1111111115){|i| puts i}' |\
  ruby -pe '$_.gsub!(/^(\d+)/){Time.at($1.to_i).to_s}'
Fri Mar 18 10:58:31 JST 2005
Fri Mar 18 10:58:32 JST 2005
Fri Mar 18 10:58:33 JST 2005
Fri Mar 18 10:58:34 JST 2005
Fri Mar 18 10:58:35 JST 2005

Golf:

% echo 1111111111 |ruby -pe 'sub(/^\d+/){Time.at($&.to_i)}'
Fri Mar 18 10:58:31 JST 2005

-- 
eban