args.sh

args.sh

#!/bin/sh

set -euo pipefail

#declare valid arguments here
bar=
baz=

function parse_args() {
    args=()
    local i=1
    while [ $i -le $# ]; do
        local arg="${!i}"
        case "${arg}" in 
            --*=*)
                arg=${arg#--}
                local key="${arg%=*}"
                if [ ! ${!key+x} ]; then
                    echo "invalid option -- $key" 1>&2
                    exit 2
                fi
                local value="${arg#*=}"
                eval $key=\$value
                ;;
            --?*)
                local key=${arg#--}
                if [ ! ${!key+x} ]; then
                    echo "invalid option -- $key" 1>&2
                    exit 2
                fi
                if [ $i -ge $# ]; then
                    echo "option requires an argument -- $key" 1>&2
                    exit 2
                fi
                let "i++"
                local value=${!i}
                eval $key=\$value
                ;;
            *)
                args+=("$arg")
        esac
        let "i++"
    done
}
parse_args "$@"

echo "bar is $bar"
echo "baz is $baz"
for arg in "${args[@]}"; do
  echo "arg is $arg"
done