From: dblack@...
Date: 2007-01-03T08:30:09+09:00
Subject: Re: Delete line from file

Hi --

On Wed, 3 Jan 2007, William James wrote:

>
> Jules wrote:
>> Hi,
>>
>> Given a line number, what is the best way to delete this line from a
>> file?
>>
>> And given an array of line numbers, what is the best way to delete
>> these lines from a file?
>>
>> Thanks,
>>
>> Jules
>
> lines = IO.readlines('junk1')
> [1,3,5].each{|n| lines.slice!(n) }

That's going to have a side-effect problem:

irb(main):004:0> a = %w{ a b c d e f }
=> ["a", "b", "c", "d", "e", "f"]
irb(main):005:0> [1,3,5].each {|e| a.slice!(e) }
=> [1, 3, 5]
irb(main):006:0> a
=> ["a", "c", "d", "f"]

You'd probably want to reverse the list of indices.


David

-- 
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