Bash Xargs Sleep (Multiple Command Line Arguments)

Question

Ok so I have the following script that updates Route43 DNS entries. Unfortunately there is a limit to the number of calls per second you can make so I need to make the final Xargs command sleep for about a second between each iteration.

I've tried a couple of things like ' {../cli53 blah; sleep 10; } ' and I cant seem to get it to work. Does anyone have any suggestions please:

#!/bin/bash

set root='dirname $0'
ec2-describe-instances -O ******* -W ******* --region eu-west-1 |
perl -ne '/^INSTANCE\s+(i-\S+).*?(\S+\.amazonaws\.com)/
and do { $dns = $2; print "$1 $dns\n" }; /^TAG.+\sName\s+(\S+)/
and print "$1 $dns\n"' |
perl -ane 'print "$F[0] CNAME $F[1] --replace\n"' |
grep -v 'i-' | xargs --verbose -n 4 /usr/local/bin/cli53 rrcreate -x 5 contoso.com

---

Edit: Thanks Etan for the Answer. Here is my solution for anyone else that needs it:

I had to include the -I %variable% switch into the xargs statement aswel to make sure that the feed in was passed as parameters to cli53 but it all looks to be working nicely now.

#!/bin/bash

set root='dirname $0'
ec2-describe-instances -O ******* -W ******* --region eu-west-1 |
perl -ne '/^INSTANCE\s+(i-\S+).*?(\S+\.amazonaws\.com)/
and do { $dns = $2; print "$1 $dns\n" }; /^TAG.+\sName\s+(\S+)/
and print "$1 $dns\n"' |
perl -ane 'print "$F[0] CNAME $F[1] --replace\n"' |
grep -v '^i-' |
xargs --verbose -n 4 -I myvar /bin/sh -c '{ /usr/local/bin/cli53 rrcreate -x 5 contoso.com 'myvar'; sleep 1; printf "\n\n"; }'

Answer 1

The simplest solution would be to simply put the cli53 and sleep calls in a script and use xargs to execute the script.

If you don't want to do that you should be able to do what you were trying to do with this:

... | xargs ... /bin/sh -c '{ /usr/local/bin/cli53 ... "$@"; sleep 10; }' -