soa

#!/usr/bin/env bash

soa_usage() {
	t=$([ -t 0 ] && echo true || echo false)
	mdformat $t <<EOusage | ${PAGER:-cat} 
**NAME**
	${0##*/} - update SOA serial number in zonefile

**SYNOPSIS**
	${0##*/} [**-vqdn**] _zonefile_

**DESCRIPTION**
	Finds a zonefile's SOA record and updates the serial number
	based on the current date, using the format YYYYMMDDII, where II
	is 00 if the previous serial number was "older", or increments
	by 1 if the old SOA matched the current date.
	
	Options:
	-h	This help
	-r	RCSify the SOA file
	-R	Don't RCSify the SOA file
	-v	Verbose, default if on terminal
	-q	Quiet, default if not on terminal
	-d	Debug
	-n	Just show what we re doing, don't actually do it

	It's likely you'd want to use -d and -n together when testing.
	Quiet mode turns off debug. Last option wins.

	RCS will be used automatically if the SOA file is RCSified and
	checked in. This behiour is suppressed with **-R**.  Specifying **-r**
	will basically cause the update to fail if the file can't be
	RCSified for some reason (tools not available, etc.) If the SOA
	file is already checked out then it will not be checked in.

**EXAMPLES**
	${0##*/} /etc/named/master/example.com.zonefile

**SEE ALSO**

EOusage
}

mdformat() {
	local md so us mr me
	local t="${1:-false}"
	if "$t" || [ -t 1 ]; then
		if [[ $(uname -s) = Linux ]]; then
			# https://www.linuxcommand.org/lc3_adv_tput.php
			md=$(tput -T "${TERM:-xterm}" bold)   # bold
			so=$(tput -T "${TERM:-xterm}" rev)   # standout (inverse?)
			us=$(tput -T "${TERM:-xterm}" smul)   # underline
			#mr=$(tput mr)	 # reverse
			me=$(tput -T "${TERM:-xterm}" sgr0)   # exit attributes
		else
			md=$(tput md)	# bold
			so=$(tput so)	# standout (inverse?)
			us=$(tput us)	# underline
			#mr=$(tput mr)	 # reverse
			me=$(tput me)	# exit attributes
		fi
	fi
	sed -E \
		-e "s/\*\*([^*]+)\*\*/$md\1$me/g" \
		-e "s/\*([^*]+)\*/$us\1$me/g" \
		-e "s/_([^_]+)_/$us\1$me/g" \
		-e "s/^#+ *(.+)/$so\1$me/g" \
		-e "s/#([^#]+)#/$mr\1$me/g"
}

Verbose=$([ -t 0 ] && echo true || echo false)
Quiet=false; Debug=false; Doit=true
while getopts hrRvqdn opt; do
	case "$opt" in
		h) soa_usage; exit 0 ;;
		r) useRCS=true ;;
		R) useRCS=false ;;
		v) Verbose=true; Quiet=false ;;
		q) Verbose=false; Quiet=true; Debug=false ;;
		d) Verbose=true; Quiet=false; Debug=true ;;
		n) Doit=false ;;
		*) soa_usage; exit 64 ;;
	esac
done
shift $((OPTIND - 1))

SOAfile="$1"
err=""
if [ -z "$SOAfile" ]; then
	err="No file specified. -h for help"
elif [ ! -e "$SOAfile" ]; then
	err="File not found: $SOAfile"
fi
if [ -n "$err" ]; then
	printf 'ERROR: %s\n' "$err" >&2
	exit 64
fi

read line soa < <(awk -v field=5 '/^@/ { if($2=="IN"){field++} if($6=="("){field++} for(i=1;i<field;i++){if(i==NF){field=field-NF;getline;i=1}} print NR,$field}' $SOAfile)

newsoa=$(date '+%Y%m%d00')

while [[ $((newsoa++)) -le "$soa" ]]; do :; done

printf -v cmd 'sed -i.bak -e "%ds/%s/%s/" "%s"' "$line" "$soa" "$newsoa" "$SOAfile"

#$Verbose && printf "%s: %s -> %s\n" "$SOAfile" "$soa" "$newsoa"
#$Debug && echo "sed -i.bak \"${line}s/$soa/$newsoa/\" \"$SOAfile\""
#$Doit && sed -i.bak "${line}s/$soa/$newsoa/" "$SOAfile"; then

$Verbose && printf "%s: %s -> %s\n" "$SOAfile" "$soa" "$newsoa"
$Debug && printf 'DEBUG: %s\n' "$cmd"
$Doit && eval $cmd