Wrapper script for ipset listing

[Born Without <blackhole@xxxxxxxxxxx>]

Hello list!

As I was missing those features in the ipset set listing capabilities:

- show sum of set members
- suppress listing of headers
- choose a delimiter character for separating member entries

I wrote a little wrapper script (for the bash shell) to support them.
For those who like, you'll find it attached.

Comments etc. welcome...

Best regards

#!/bin/bash

# -----------------------------------------------------------------
ipset="/sbin/ipset"
delim=" "
TMOUT=30
# -----------------------------------------------------------------

set -f
shopt -s extglob

show_count=0 show_members=0 headers_only=0 names_only=0 i=0

[[ -x $ipset ]] || {
	printf "ipset binary \`%s' does not exist, or is not executable" "$ipset"
	exit 1
}
while (($#)); do
	case "$1" in
		-h) printf "%s [-{c|h|m|n|r|s|t}] [...] [-d char] [set-name] [...]\n" "${0//*\//}"
			exit 0
		;;
		-c) show_count=1
			shift
		;;
		-m) show_members=1
			shift
		;;
		-n) names_only=1
			shift
		;;
		-t) headers_only=1
			shift
		;;
		-d) if [[ -z $2 ]]; then
				printf "delim character is missing\n" >&2
				exit 2
			else
				if ((${#2} > 1)); then
					printf "only one character is allowed as delim\n" >&2
					exit 2
				fi
				delim="$2"
				shift 2
			fi
		;;
		-s|-r) arr_par[i++]="$1"
			shift
		;;
		-o) if [[ $2 != plain ]]; then
				printf "only plain output is supported\n" >&2
				exit 2
			else
				shift 2
			fi
		;;
		-\!|-f) shift
		;;
		*) break
	esac
done
if ((names_only)); then
	if ((show_count || show_members)); then
		printf "options -n and -c|-m are mutually exclusive\n" >&2
		exit 2
	fi
	"$ipset" l -n
	exit $?
fi
if ((headers_only)); then
	if ((show_count || show_members)); then
		printf "options -t and -c|-m are mutually exclusive\n" >&2
		exit 2
	fi
	"$ipset" l -t
	exit $?
fi

i=0
if [[ $1 ]]; then
	arr_opts=("$@")
else
	while IFS=$'\n' read -r; do
		arr_opts[i++]="$REPLY"
	done < <("$ipset" l -n)
	i=0
fi

for x in "${!arr_opts[@]}"; do
	while read -r; do
		if [[ $REPLY = Name:* ]]; then i=0
			printf "\n%s\n" "$REPLY"
			continue
		elif [[ $REPLY = @(Type|Revision|Header|Size in memory|References|Members):* ]]; then
			continue
		elif [[ -z $REPLY ]]; then
			continue
		else
			if ((show_members)); then
				printf "%s$delim" "$REPLY"
			fi
			let i+=1
		fi
	done < <("$ipset" l "${arr_opts[x]}" "${arr_par[@]}")
	if ((show_members)); then
		printf "\n"
	fi
	if ((show_count && i)); then
		printf "Member count: %d\n" $i
	fi
done