How read line by line in bash and assign the value to a variable [duplicate] - linux

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Read a file line by line assigning the value to a variable [duplicate]
(10 answers)
Closed 2 years ago.
I have a file called ips.txt and it has values like below:
cat ips.txt
abc.com. 10.120.20.4 10.120.20.5 ... # there can be many ips separated by a space
xyz.com. 10.120.20.6
I want to read this file line by line with a loop and do some other works.
And als I need to remove that . as well at the end of each domain name abc.com. and assign each ip to a variable (if it can be stored to an array, it is great)
So here's what I tried:
input="ips.txt"
while IFS= read -r line
do
echo "$line"
domain="" # need to assign abc.com
ip_one= "" # need to assign the first ip occurence
ip_two= "" # need to assign the second ip occurence
...
ip_n= "" # need to assign the nth ip occurence
# some other commands I need to execute with domain name and all the ips collected
done < "$input"
how can I assign the ip values to different variables? and use them? It is better if I can Store the IP's in a array like data type so it is more easier as I don't know how many IP's are there for some line in the ips.txt file.
Can someone help me do this?

Answer 1

Using set, and shift:
while IFS= read -r line; do
set $line
domain=$(sed 's/\.$//' <<< "$1")
shift
for ip in $#; do
echo "domain: $domain ip: $ip"
done
done < "$input"

Answer 2

Start with a standard array read. Assign to $#, use parameter expansion to strip the dot, then shift it off the stack, and you can assign back to your original array.
input="ips.txt"
declare -A lookup=()
while read -a ips # ips is an array
do set -- "${ips[#]}" # assign the array to $#
domain="${1%.}" # assign abc.com without the dot
shift # dump the first column; now $# is just the IP's
for ip in "$#"; do lookup[$ip]="$domain"; done # assign the domain to each IP
done < "$input"
now
$: echo ${lookup[10.120.20.5]}
abc.com