[CentOS] xargs with max each line / argument

Tue May 17 13:15:45 UTC 2011
Andy Holt <centos-list at orgdotuk.org.uk>

> -----Original Message-----
> From: centos-bounces at centos.org 
> [mailto:centos-bounces at centos.org] On Behalf Of neubyr
> Sent: 17/05/2011 06:36
> To: CentOS mailing list
> Subject: [CentOS] xargs with max each line / argument
> How do I pass xargs input one line at a time to subsequent command?
> For example I want to install rubygems by reading a text file as shown
> below, however the arguments are getting passed all at once to the
> 'gem install' command. I hace tried -L (max-lines) and -n (max args)
> options, but it didn't work. What's missing here?? Any help?
> $ cat gem.list.1
> mkrf
> rake
> xmlparser
> $ awk '{ print $0 }' gem.list.1 | xargs -L 1 -0 -I name sudo 
> gem install name
> ERROR:  could not find gem mkrf
> rake
> xmlparser
>  locally or in a repository
> thanks,
> neuby.r


As others have mentioned, a simple cat or use of < into xargs will simplify things.  The max-args switch _is_ the one you are
looking for:

--max-args=max-args, -n max-args


cat gem.list.1 | xargs --max-args=1 sudo gem install

will do what you want, I think - please test it first.  You could add --interactive to xargs to help with this, or even just:

cat gem.list.1 | xargs --max-args=1 echo sudo gem install

which will just dump the commands that would be run (using echo).

hth   Andy