#!/bin/bash
# Desc: Writes stdin to disk every 5 minutes

yell() { echo "[$(date --iso-8601=ns)]:$0: $*" >&2; }      #o Yell, Die, Try Three-Fingered Claw technique
die() { yell "$*"; exit 111; }     #o Ref/Attrib: https://stackoverflow.com/a/25515370
try() { "$@" || die "cannot $*"; } #o

declare -a buffer # Initialize buffer array
scriptTTL="15";
bufferTTL="5";

magicWriteBuffer() {
    printf "%s\n" "${buffer[@]}" >> /dev/shm/$(date +%s)..bkFreqWrite-output.txt;
}

bufferRound=0
# Run until script TTL seconds pass
while [[ $SECONDS -lt "scriptTTL" ]]; do
    bufferTOD="$((SECONDS + $bufferTTL))";
    lineCount=0
    # Start and fill buffer until buffer time-of-death (TOD) arrives
    while read -r line && [[ $SECONDS -lt "$bufferTOD" ]]; do
	# Append line to buffer
	buffer+=("$line");
	echo "Processing line:$lineCount";
	echo "Current line   :$line";
	echo "buf elem count :${#buffer[@]}";
	((lineCount++));
    done;
    # Export buffer to asynchronous processing.
    magicWriteBuffer &
    unset buffer;
    # Increment buffer round
    ((bufferRound++));
done;