UNIX for Beginners Questions & Answers

Hello Forum,

I'm making very good progress on my report thanks to the very helpful people on this forum. I've been able to successfully create my report for my Red Hat servers. But I do have a few ubuntu servers in the mix and I'd like to capture some data from them when an ssh connection is made.

I have a command here to find the inactive kernels on a Red Hat VM:

Code:

rpm -qa | grep '^kernel-[0-9]' |grep -vE `uname -r` | paste -sd \;

I'm trying to get this one line command to be Linux Type aware by issuing something like the following where if the os-release is Red Hat then I issue the command above to find the Red Hat installed kernels. This isn't working but this is what I'm trying to do:

Code:

awk -F= '/^NAME/{print $2}' /etc/os-release 2>/dev/null || grep Red |cat /etc/redhat-release 2>/dev/null || lsb_release -a 2>/dev/null | grep Description | cut -f2

I'm not sure if it's even possible but I would really like to issue the command to find the installed kernels for Red Hat servers and if the servers are ubuntu then issue another command for Ubuntu inactive kernels. I'm not sure what the command is to find the Ubuntu inactive kernels so I'll look that up...but for this post could someone point me in the right direction here on how to write the one line command to check for O/S type and issue commands based on that type.

Thank you.

Why not simply ls the /boot directory?

Hello RudiC,

I researched how to use ls and /boot to find the distribution I was connecting to but I couldn't find a solution. But I did find another way using python that seems to be working for me with my very early tests:

Code:

python -mplatform | grep -qi red && echo "RedHat" || echo "ubuntu"

This does work in that it looks for the work

Code:

red

which means I can identify Red Hat Servers. Where I can see my code failing though is that my assumption is that if it's not Red Hat then it must be Ubuntu. I'm trying now to find a way to identify each type of distribution we have and specifically test for Red Hat (like I'm currently doing) or Ubuntu or even CentOS. Would you or someone else have a suggestion for me on how I can use my code to test for various types of Linux distributions?

Thank you.

How about the

Code:

lsb_release -a

command?

Hello again RudiC,

I suppose I could use lsb_release -a as a check...but what would be the one line command to check if Red Hat to run an instruction and if not Red Hat and it's Ubuntu to run a different instruction? That's the part I'm having trouble with now. Here is the code I've tried using the python bit I found:

Code:

if python -mplatform | grep -qi red; then rpm -qa | grep '^kernel-[0-9]' | grep -vE `uname -r` | paste -sd \; else python -mplatform | grep -qi Ubuntu; then echo "This is Ubuntu"

Thank you.

man lsb_release might help. E.g.

Code:

$ lsb_release -is
Ubuntu

A case statement could be used

Code:

case  $(lsb_release -is) in
    red*)    # run red hat command
    ;;
    Ubu*)    # run ubuntu command
    ;;
esac