Shell Programming and Scripting

Hello Forum,

We have two bootstraps of Chef in our environment which are identified by colour:

Code:

/var/chef/cache/cookbooks/bootstrap_cookbooks_version_green

and

Code:

/var/chef/cache/cookbooks/bootstrap_cookbooks_version_red

I'm attempting to identify which version is installed based on the name of the file. So far I've been able to use the following find command to help me identify the full name:

Code:

find /var/chef/cache/cookbooks/ -name "bootstrap*" -print

I think I need to redirect the result using 2>/dev/null and then pipe to use grep and identify if the filename has red or green in the name or the name isn't found.

I'd like to be able to make the report a little cleaner by reporting back if the filename had either "red" or "green" or couldn't find the file.

One more requirement is that I would like to have this command in a one liner if possible.

Thanks in advance for any advice you can provide me.

Do the two file versions coexist, or is there one single file max?
And, why a one liner? What be the benefit thereof?

Hello RudiC and thank you for this reply and inquiry.

The two file versions will never coexist together. It will either be:
bootstrap_cookbooks_version_green
bootstrap_cookbooks_version_red
or the file won't exist at all.

The reason for the oneliner is because I'm using a "Here Doc" in Bash to connect once to a group of servers and I'm issuing multiple commands against each server for a report. I know there are better ways to do this but this is the script we started with and what I'm supporting for now since the report from this script is actively used daily. Eventually I will move us to another way to retrieve the results we need but for now I'm keeping this script alive. So far I've been able to acheive what I need in this Here Doc step of the script whereby each data I want to retrieve from the remote server is contained all in one liner commands.

I hope this explanation is enough as to why I'm hoping I can answer this question using a one line command to identify the filename in this folder.

Thank you.

Well, then, try

Code:

TMP=$(find /where/so/ever -iname "*bootstrap*"); case ${TMP##*_} in (green) echo "is green";; (red) echo "is red";; (*) echo "is missing";; esac

You could, of course, also use grep for the same purpose.

If you know the possible pathnames then you don't need find and grep.

Code:

if [ -f /var/chef/cache/cookbooks/bootstrap_cookbooks_version_green ]
then echo "green"
elif [ -f /var/chef/cache/cookbooks/bootstrap_cookbooks_version_red ]
then echo "red"
else echo "does not exist"
fi

Thanks RudiC...your code worked perfectly!

Thanks for the reply MadeinGermany. I needed a one liner but I'll save your example code for future reference!

Appreciate all your help.

How about one of these two lines:

Code:

[ -f /var/chef/cache/cookbooks/bootstrap_cookbooks_version_* ] && echo /var/chef/cache/cookbooks/bootstrap_cookbooks_version_* | sed 's/.*version_//'
f=$(echo/var/chef/cache/cookbooks/bootstrap_cookbooks_version_*) && [ -f "$f" ] && echo ${f##*_}

The second has the advantage of using POSIX shell builtin commands.

Andrew