Subject: Re: bug#19240: cut 8.22 adds newline

From: Eric Blake <[email-masked]>
Date: Thu, 04 Dec 2014 14:56:56 -0700

On 12/04/2014 02:13 PM, John Kendall wrote:
> Yes, that's what I've done.  The corner case I mentioned is 
> handled badly by this, however.  In the corner case $FILE 
> is a list of files separated by a newlines.  Solaris cut would 
> list them and then the ============= would be tacked 
> on to the last line:

Again, mention your goal up front, and you can save us some iterations.
 So you really DO want to grab a rectangular region of text, and append
to just the last line, rather than chop a single line of input at a
fixed length (it was not obvious to us from the naming or your example
that you intended for $FILE to contain newlines).

So, my solution of using command substitution still does this, and portably:

 echo "$(echo "$FILE ============================"| cut -c1-30)" \
      " matches =========="

So does sed, although no longer a short one-liner:

echo "$FILE" | sed -e 's/^\(.\{30\}\).*/\1/' \
                   -e '$ {' \
                   -e   's/$/ ============================/' \
                   -e   's/^\(.\{30\}\).*/\1/' \
                   -e   '$ s/$/ matches ==========/' \
                   -e '}'

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org