Example script with docopts

esempio.sh

#!/usr/bin/env bash
# shellcheck disable=SC2128
SOURCED=false && [ "$0" = "$BASH_SOURCE" ] || SOURCED=true

debug=false
parallel=false
query=''
topic=''

read -rd '' docstring <<EOF
Usage:
  esempio.sh [options] --query QUERY --topic TOPIC
  esempio.sh ( -h | --help )
  esempio.sh ( --version )

  Options:
    -d, --debug             Enable debug output.
    -p, --parallel NJOBS    Number of parallel jobs [default: 2]
    -q, --query QUERY       Query to perform.
    -t, --topic TOPIC       Topic to process.
    -h, --help              Show this help message and exits.
    --version               Print version and copyright information.
----
esempio.sh 0.1.0
copyright (c) 2018 Daniele Foroni
MIT License
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
EOF

eval "$(echo "$docstring" | docopts -V - -h - : "$@" )"

# bash strict mode
# https://balist.es/blog/2017/03/21/enhancing-the-unofficial-bash-strict-mode/
if ! $SOURCED; then
  set -euo pipefail
  IFS=$'\n\t'
fi

#################### Utils
if $debug; then
  echodebug() { 
    (>&2 echo -en "[$(date '+%F_%k:%M:%S')][DEBUG]\\t")
    (>&2 echo "$@")
  }
else
  echodebug() { true; }
fi
####################

echodebug "debug: $debug"
echodebug "parallel: $parallel"
echodebug "query: $query"
echodebug "topic: $topic"

exit 0

parametri.sh

#!/usr/bin/env bash
# shellcheck disable=SC2128
SOURCED=false && [ "$0" = "$BASH_SOURCE" ] || SOURCED=true
if ! $SOURCED; then
  set -euo pipefail
  IFS=$'\n\t'
fi

# controllo il numero di parametri "$#", se meno di 3 -> errore
if [ "$#" -le 3 ]; then
    (>&2 echo "Error: less parameters than expected.")
fi

primo="$1"
secondo="$2"

declare -a altri
altri=()
for i in $(seq 3 $#); do
  altri+=("${!i}")
done

echo "primo: $primo"
echo "secondo: $secondo"

# ${altri[*]} is for printing, if you need to pass to a script
# use "${altri[@]}"
echo "altri: ${altri[*]}"

exit 0