Configuration Files

Key-Value Config

Reading a Setting

Many simple config files use name=value lines. A script can read each line and keep the value for the key it needs.

Program

Play the script to scan fixed config text for a selected key.

parse_key_values.sh 
#!/usr/bin/env bash

config=$'host=local\nport=8080\ndebug=false'
selected_key=
selected_value=""
while IFS="=" read -r key value; do
    if [[ "$key" == "$selected_key" ]]; then
        selected_value=$value
    fi
done <<< "$config"
echo "$selected_key=$selected_value"

#!/usr/bin/env bash

config=$'host=local\nport=8080\ndebug=false'
selected_key=
selected_value=""
while IFS="=" read -r key value; do
    if [[ "$key" == "$selected_key" ]]; then
        selected_value=$value
    fi
done <<< "$config"
echo "$selected_key=$selected_value"

#!/usr/bin/env bash

config=$'host=local\nport=8080\ndebug=false'
selected_key=
selected_value=""
while IFS="=" read -r key value; do
    if [[ "$key" == "$selected_key" ]]; then
        selected_value=$value
    fi
done <<< "$config"
echo "$selected_key=$selected_value"
IFS `IFS="="` makes `read` split each line around the equals sign.
read loop `while read ...; do` processes one config line per iteration.
selected key The `if` keeps only the value whose key matches the selected setting.