From: Daniel Brumbaugh Keeney <devi.webmaster@...>
Date: 2007-11-20T08:43:11+09:00
Subject: Re: Why does IO.readlines() keep newlines?

On Nov 19, 2007 1:15 PM, Just Another Victim of the Ambient Morality
<ihatespam@hotmail.com> wrote:
>     At the very least, the win32 implementation of Ruby's IO.readlines()
> method keeps the newline character on each string in the array.  Considering
> that it is the newline that defines a "line," it would not be wholly
> unreasonable to omit it from the array, returned.  I would have imagined
> that it was implemented using String.split(), which omits the splitting
> character.  On a simply practical note, I'm sure the former is more popular
> than the latter in the following:
>
>
> out = File.open('file.txt', 'r'){|file| file.readlines.collect{|line|
> line.chomp}}
> out = File.open('file.txt', 'r'){|file|
>                }
>
>
>     ...in that rarely do people actually want newlines in their strings.
>     Interestingly enough, I discovered this behaviour from a bug in a
> program which was hidden by another peculiar function, puts().  Can you
> imagine my surprise that puts() not only appends a newline to a string
> printed to stdout but, if a newline already exists, it doesn't bother
> appending one!  So, printing strings with puts() can hide whether strings
> have a newline or not.  Weird...
>     So, who thinks my suggested change is a good idea?  How do I go about
> popularizing my opinion?
>     Thank you...
>


I'm going to speculate that readlines does this because of operating
system differences in line endings.
For compatibility between most systems, it would have to remove line
feeds (\x0A) or line-feed/carriage return combinations (\x0D\x0A).

I personally rather prefer the current behavior of readline. I don't
think puts matters, and is certainly not worth changing. I'm aware of
their behavior and if it matters, I code accordingly.

humbly,
Daniel Brumbaugh Keeney