I want to generate a comma separated ip values with mapped ports and create a string.
Here is my code:
zk_ip="['192.168.0.10', '192.168.0.20', '192.168.0.30']" zk_host="" for i in $zk_ip[@] do add=$(echo "$i:2181") zk_host="$zk_host $add" done echo $zk_host Output:
[192.168.0.10,:2181 192.168.0.20, :2181 192.168.0.30]:2181 Expected ouptut:
192.168.0.10:2181, 192.168.0.20:2181, 192.168.0.30:2181 So, you have a JSON-ish array that you want to modify (JSON strings are enclosed in double quotes).
I would use a JSON parser to manage this: jq
zk_ip="['192.168.0.10', '192.168.0.20', '192.168.0.30']" new_ip=$(echo "$zk_ip" | tr "'" '"' | jq -c 'map("\(.):2181")') echo "$new_ip" ["192.168.0.10:2181","192.168.0.20:2181","192.168.0.30:2181"] If you want the output to not look like JSON, you can do:
new_ip=$(echo "$zk_ip" | tr "'" '"' | jq -r 'map("\(.):2181") | join(", ")') echo "$new_ip" 192.168.0.10:2181, 192.168.0.20:2181, 192.168.0.30:2181 
jq is a tricky little functional language. That map function iterates over an array (the input string), applies the transformation to each element, and returns a new array. The join function should be obvious. The -r option is for "raw" output (not JSON-formatted data). See the jq info page.You may use:
zk_ip="['192.168.0.10', '192.168.0.20', '192.168.0.30']"
zk_host="" for i in ${zk_ip//[][,\']/}; do zk_host+="$i:2181, " done echo "${zk_host%, }" 192.168.0.10:2181, 192.168.0.20:2181, 192.168.0.30:2181 
zk_ip value as shown in question is passed from some other script?Assuming that you have your IP addresses in an array, such as
zk_ip=( '192.168.0.10' '192.168.0.20' '192.168.0.30' ) then,
( IFS=','; printf '%s\n' "${zk_ip[*]/%/:2181}" ) would print
192.168.0.10:2181,192.168.0.20:2181,192.168.0.30:2181 Setting IFS makes "${zk_ip[*]}" expand to a comma-delimited string with all the entries of the array. With /%/:2181 each element is suffixed with the string :2181 before printing.
jsonmodule to make it JSON, and then you can process it in bash withjq). Is there a reason you don't define it aszk_ip=( 192.168.0.10 192.168.0.20 192.168.0.30 ), which is the native format for defining a bash array?zk_ip='["192.168.0.10", "192.168.0.20", "192.168.0.30"]'-- note the single quotes on the outside and the double quotes on the inside."${zk_ip[@]}"to iterate -- the curly braces are mandatory when you're using[@]).