Shell scripting kungfu

[Randy Pratt]

On Fri, 18 Jan 2008 11:09:14 -0600
Paul Schmehl <pauls at utdallas.edu> wrote:

> I need to do the following:
> 
> Take a list of various strings, one of which is a quoted IP address, and 
> extract the IPs.  (Done that.)
> 
> Then take the list of IPs and convert them to a list of IPs with masks on a 
> single line.
> 
> IOW, I have converted the original list to this:
> 
> x.x.x.x
> x.x.x.x
> x.x.x.x
> x.x.x.x
> 
> Now I need to remove the newlines and add /32, to the end of each IP so that I 
> have this:
> x.x.x.x/32,x.x.x.x/32,x.x.x.x/32,etc.
> 
> I got close with sed, but I'm not quite there.
> 
> I got this:
> 
> x.x.x.x/32,x.x.x.x
> x.x.x.x/32,x.x.x.x
> x.x.x.x/32,x.x.x.x
> 
> Here's the code I used:
> cat hostlist | cut -d',' -f2 | cut -d'"' -f2 | sort | uniq | grep -v "inet" | 
> sed '/[^*]$/N;s/\n */\/32,/'
> 
> What am I missing?

I'm sure you'll get a lot of comments on this one ;-)

Here's my one-liner take:

while read line; do echo -n "${line}/32,"; done < hostlist | sed 's/\,$//'

or to be a bit more understandable:

while read line; do
  echo -n "${line}/32,"
done < hostlist | sed 's/\,$//'

the little sed part just removes the last comma from the list.

HTH,

Randy
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