问bash中以逗号分隔的范围(1,2,4-5)的Intersect/join列表

EN

#!/usr/bin/env bash

# Turn a string like 1,3,5-10 into one number per line, filling in ranges
expand() {
    local IFS=,
    # For each comma-separated element
    for elem in $1; do
        # If it's a range, print out each number in the range
        if [[ $elem =~ ([0-9]+)-([0-9]+) ]]; then
            for (( i = BASH_REMATCH[1]; i <= BASH_REMATCH[2]; i++ )); do
                printf "%d\n" "$i"
            done
        else
            # And if it's just a scalar, print that number.
            printf "%d\n" "$elem"
        fi
    done
}

list_and() {
    # Add each element in the first argument to an associate array,
    # and then for each element of the second argument, see if it also
    # exists in that array. If so, add it to the result.

    local -A arr1
    for elem in $(expand "$1"); do
        arr1[$elem]=1
    done
    
    local -a intersection
    for elem in $(expand "$2"); do
        if [[ -v arr1[$elem] ]]; then
            intersection+=("$elem")
        fi  
    done

    local IFS=,
    printf "%s\n" "${intersection[*]}"
}

list_or() {
    # Populate a sparse array using the numbers from arguments
    # as indexes.
    
    local -a union
    for elem in $(expand "$1") $(expand "$2"); do
        union[$elem]=$elem
    done

    local IFS=,
    printf "%s\n" "${union[*]}"
}

printf "%s\n" "$(list_and '1,2,3' '0,1,3-4,6,8-10')"
printf "%s\n" "$(list_or '1-5' '0,1,3-4,6,8-10')"