Bash - Break up returned value from MySQL query - mysql

Question

I am trying to break up a returned value from a mysql call in a shell script. Essentially what I have done so far is query the database for IP addresses that I have stored in a specific table. From there I store that returned value into a bash variable. The code is below:
#!/bin/bash
# This file will be used to obtain the system details for given ip address
retrieve_details()
{
# get all the ip addresses in the hosts table to pass to snmp call
host_ips=$(mysql -u user -ppassword -D honours_project -e "SELECT host_ip FROM hosts" -s)
echo "$host_ips"
# break up the returned host ip values
# loop through array of ip addresses
# while [ ]
# do
# pass ip values to snmp command call
# store details into mysql table host_descriptions
# done
}
retrieve_details
So this returns the following:
192.168.1.1
192.168.1.100
192.168.1.101
These are essentially the values I have in my hosts table. So what I am trying to do is break up each value such that I can get an array that looks like the following:
arr[0]=192.168.1.1
arr[1]=192.168.1.100
arr[2]=192.168.1.101
...
I have reviewed this link here: bash script - select from database into variable but I don't believe this applies to my situation. Any help would be appreciated

Answer 1

host_ips=($(mysql -u user -ppassword -D honours_project -e "SELECT host_ip FROM hosts" -s));
outer () will convert that in array. But you need to change your IFS (Internal Field Separator) to a newline first.
IFS=$'\n';
host_ips=($(mysql -u user -ppassword -D honours_project -e "SELECT host_ip FROM hosts" -s));
unset IFS;
for i in ${host_ips[#]} ; do echo $i ; done;
to print with key
for i in "${!host_ips[#]}"
do
echo "key :" $i "value:" ${host_ips[$i]}
done

Answer 2

wspace#lw:~$ echo $host_ips
192.168.1.1 192.168.1.100 192.168.1.101
wspace#lw:~$ arr=($(echo $host_ips))
wspace#lw:~$ echo ${arr[0]}
192.168.1.1
wspace#lw:~$ echo ${arr[1]}
192.168.1.100
wspace#lw:~$ echo ${arr[2]}
192.168.1.101
wspace#lw:~$ echo ${arr[#]}
192.168.1.1 192.168.1.100 192.168.1.101
wspace#lw:~$
maybe this is what you want