Question

I’m new to bash and I just want to load a list from a file mentioning that all the lines starting with # or ; should be ignored (and also empty ones).

As expected each valid line should became a string in the list.

I need to perform some action with each (valid) element of this list.

Note: I have a for loop like for host in host1 host2 host3.

Answer 1

You can use bash builtin command mapfile to read file to an array:

# read file(hosts.txt) to array(hosts)
mapfile -t hosts < <(grep '^[^#;]' hosts.txt)

# loop through array(hosts)
for host in "${hosts[@]}"
do
    echo "$host"
done