Combine two commands in bash elif (FreeNAS) - bash

Question

I'm really sorry to annoy to you again with my problem but it seems I'm about to finish. My goal is to create a bash-script that checks if a IP-address is still online or a scrub is in progress and if not that my systems shuts down. My script, which is currently in use, looks like this
#!/bin/bash
hosts=(
10.10.0.100 #Client 1
10.10.0.101 #Client 2
10.10.0.102 #Client 3
10.10.0.103 #Client 4
10.10.0.104 #Client 5
)
for host in "${hosts[#]}"; do
if ping -c 1 -i 1 "$host" >/dev/null; then
echo "No Shutdown - At least one PC ($host) is online"
exit 0
fi
done
echo "No PC is online - Shutdown"
bash shutdown -p now
I did some research and found the following command, to check if my scrub is in progress
if [ $(zpool status | grep 'scrub in progress') ]; then
echo "No Shutdown - Scrub in progess"
exit 0
fi
But i have problems in combining these two. I want my script to first check the IPs and if they all are offline then check for a scrub before it shuts down the machine. So both if-cases have to be false (ips offline and scrub not in progress) but they should be processed chronological and if the first if-case returns a IP which is online the script should stop.
Maybe somebody can help me?

Answer 1

To check if a command output contains a string, just:
if zpool status | grep -q 'scrub in progress'; then
The [ $(zpool status | grep 'scrub in progress') ] is invalid. The $( .. ) will expand to multiple words and will run [ scrub in progress ]. Because in is not a valid operator for [, then [ will print an error message and exit with 2. Just check the error status of grep.

Answer 2

For me, the answer is trivial:
hosts=(
10.10.0.100 #Client 1
10.10.0.101 #Client 2
10.10.0.102 #Client 3
10.10.0.103 #Client 4
10.10.0.104 #Client 5
)
for host in "${hosts[#]}"; do
if ping -c 1 -i 1 "$host" >/dev/null; then
echo "No Shutdown - At least one PC ($host) is online"
exit 0
fi
done
if $(zpool status | grep 'scrub in progress'); then
echo "No Shutdown - Scrub in progess"
exit 0
fi
echo "No PC is online and Scrub is not in progress - Shutdown"
shutdown -p now
Or did I miss the point?
Mind a couple of corrections inside of your code: remove the square brackets around the if test and remove the bash before shutdown.

Answer 3

You can negate the exit status by using !
if ! ping -c 1 -i 1 "$host" >/dev/null; then
if ! [[ $(zpool status | grep 'scrub in progress') ]]; then
echo "No PC is online - Shutdown"
bash shutdown -p now
fi
fi
## Add the rest of the script here if both conditions are true.
That basically means both condition are false, meaning there is no host up and scrub is not in progress, the opposite without the !
Check if both conditions are true just remove the !
if ping -c 1 -i 1 "$host" >/dev/null; then
if [[ $(zpool status | grep 'scrub in progress') ]]; then
echo "No Shutdown - At least one PC ($host) is online"
exit 0
fi
fi
Check if hosts are up but scrub is not running.
if ping -c 1 -i 1 "$host" >/dev/null; then
if ! [[ $(zpool status | grep 'scrub in progress') ]]; then
##: Add/run/execute your code here to start scrub.
fi
fi
If Nesting is what you want that would be something like.
for host in "${hosts[#]}"; do
if ping -c 1 -i 1 "$host" >/dev/null; then
echo "No Shutdown - At least one PC ($host) is online"
exit 0
elif ! ping -c 1 -i 1 "$host" >/dev/null; then
if ! [[ $(zpool status | grep 'scrub in progress') ]]; then
echo "No PC is online - Shutdown"
bash shutdown -p now
fi
fi
done
You can add the test for zpool inside the first if-statement.
for host in "${hosts[#]}"; do
if ping -c 1 -i 1 "$host" >/dev/null; then
if [[ $(zpool status | grep 'scrub in progress') ]]; then
echo "No Shutdown - At least one PC ($host) is online"
exit 0
fi
fi
elif ! ping -c 1 -i 1 "$host" >/dev/null; then
if ! [[ $(zpool status | grep 'scrub in progress') ]]; then
echo "No PC is online - Shutdown"
bash shutdown -p now
fi
fi
done
The first example set of if-statement should be enough though.
see help test