I have two variables in my bash script
CAR_PRICE=50000
BIKE_PRICE=20000
I am passing a command line argument while executing my .sh shell script file.
--vehicletype CAR or --vehicletype BIKE
I am able to read the vehicletype value in the script and store in another varible
VEHICLE_TYPE=<VALUE PASSED FROM COMMAND LINE ARG i.e CAR/BIKE
Now I am trying to dynamically read CAR_PRICE or BIKE_PRICE using following syntax
${${VEHICLE_TYPE}_PRICE}
to get the values of the params subtituting the first part of the variable dynamically based on the value passwed ie but it is throwing Bad Substitution error.
I tried several ways but nothing seem to work. I am new to shell script and not sure if such dynamic substitution is supported in bash script.
Any pointers would be helpful.
You can use price=${VEHICLE_TYPE}_PRICE; echo "${!price}". However, associative arrays are a better tool for this job:
declare -A vehicle_price
vehicle_price[ford]=7777
vehicle_price[toyota]=8888
vehicle_type=toyota
echo "${vehicle_price[$vehicle_type]}"
# gives
8888
You can use indirect variable reference in bash:
CAR_PRICE=50000
BIKE_PRICE=20000
VEHICLE_TYPE='CAR'
var="${VEHICLE_TYPE}_PRICE"
# variable name
echo "$var"
# variable value
echo "${!var}"
Output:
CAR_PRICE
50000