Re: [tlug] Adding text to the beginning of a file

[Scott Robbins <scottro@example.com>]

On Sun, Mar 18, 2007 at 12:30:15AM +0900, Edward Wright wrote:
> On Sat, Mar 17, 2007 at 09:28:51AM -0400, Scott Robbins wrote:
> > > export IFS=$'\n'
> > > for file in `ls`;do echo $file; done
> > 
> > I didn't know that one.  I do find that setting it null also works
> > 
> > export IFS=""
> 
> Hmm. Yeah, it does, but I don't get why. I would expect no "separating"
> to take place in that case. 

Do you mean that you think it would have just listed everything as one
long file name?  I would guess that ls has other means of figuring what
is a different file.  (Of course, if ls' method of differentation was
perfect, we wouldn't have to do tricks with spaces in the file name.)
:)

However, I don't really grok IFS very well at all--with me, it's usually
trial and error when I try to use it. 


> 
> Doing a little research turned up the fact that if IFS is not set, it
> behaves differently than if it is set with no value. (In that case it
> reverts to the default <space><tab><newline> behavior.)

That would be expected I think.  (I'm afraid of getting deeply into this
discussion as I fear I'll show a great deal of ignorance.)  

> 
> > With yours, I found that mistyping, and leaving out the $ set n as the
> > separator.  
> > 
> > 
> > export IFS='\n'   [note the typo]
> 
> This sets the field separators to backslash and 'n'. If you had a file
> name with a backslash in it, it would also be split.
> 
> try touch ab\\cd 

Yup, it did the same thing

ab
cd

Thanks.


-- 

Scott Robbins

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