[SOLVED] shell script: how to read the whole section content in a property file

Issue

Currently, i have a property file like this:

[default]
aa=aa
bb=bb

[dev]
aa=aa
dd=dd

If I want to get a certain value in a section, I can use following code:

awk -F '=' '/\['$section'\]/{a=1}a==1&&$1~/'$key'/{print $2;exit}' $configfile

But How can I get the whole section, e.g. I want a list to hold all values in dev section?

Can any one help with this?

[edit]

I may want the all values in a section to be saved in a list like this:

list=()
list=`get_section dev`

and the list content can be:

aa bb

Thanks again for your kindly help!

Solution

I think the following would be my solution to extract a section:

awk '/^\[/{x=0} $1=="["section"]"{x=1} x' section="$section" my.ini

This avoids any issues with blank lines within a section. It doesn't, however, print the list of results, or turn them into shell variables, which I gather is what you're looking for.

If your shell is bash, you might take advantage of arrays, and avoid the need for awk altogether. Associative arrays are a feature of bash 4:

declare -A conf

while IFS='=' read var val; do
    if [[ $var == \[*] ]]; then
        section="${var//[^[:alnum:]]/}"    # strip invalid chars from variable name
    elif [[ -n "$val" ]]; then
        echo " > ${section}_$var=$val"     # debugging
        declare "${section}_$var=$val"     # set to vars, bash 3
        conf["${section}_$var"]="$val"     # store in associative array, bash 4
    fi
done < my.ini

This stores your entire configuration in variables or a bash array. If you want to trim leading spaces from your values, the easiest way would be to set IFS='= ' instead of just '='.

The equivalent in POSIX shell might look something like:

while IFS='=' read var val; do
    if expr "$var" : '[[].*[]]$' >/dev/null; then
        section="$(echo "$var" | tr -d '][')"
    elif [ -n "$val" ]; then
        echo " > ${section}_$var=$val"          # debugging
        eval "${section}_$var=\"$val\""         # set to vars, POSIX
    fi
done < my.ini

The result of this would be a set of variables similar to what the declare bash 3 option above would provide. But with POSIX, we'd be stuck with eval.

If you want a random-access method to extract a variable from a section in bash, you could do it as a function:

function confitem() {

    # Usage: confitem section itemname

    local -A conf
    local var val section
    local retval=1

    while IFS='=' read var val; do
        if [[ $var == \[*] ]]; then
            section="$var"
        elif [[ -n $val ]] && [[ $section == $1 ]] && [[ $var == $2 ]]; then
            printf '%s' "$val"     # print the result
            retval=0               # set a return value for the function
            break                  # and quit the loop.
        fi
    done < my.ini
    return $retval

}

Answered By - ghoti

Answer Checked By - Senaida (WPSolving Volunteer)