Code for parsing a key/value in in file from shell script

Question

I have a file that I need to look up a value by key using a shell script. The file looks like:

HereIsAKey This is the value

How can I do so

Answer 1

I use a property file that is shared across multiple languages, I use a pair of functions:

load_properties() {
    local aline= var= value=
    for file in config.properties; do
        [ -f $file ] || continue
        while read aline; do
            aline=${aline//\#*/}
            [[ -z $aline ]] && continue
            read var value <<<$aline
            [[ -z $var ]] && continue
            eval __property_$var=\"$value\"
            # You can remove the next line if you don't need them exported to subshells
            export __property_$var
        done <$file
    done
}

get_prop() {
    local var=$1 key=$2
    eval $var=\"\$__property_$key\"
}

load_properties reads from the config.properties file populating a set of variables __property_... for each line in the file, get_prop then allows the setting of a variable based on loaded properties. It works for most of the cases that are needed.

Yes, I do realize there's an eval in there, which makes it unsafe for user input, but it works for what I needed it to do.