![skskskass.png](https://images.hive.blog/DQmfQwdXW2ZoLfBqiLbPw2GcdYbfHgrBMpp4dk53Q1qzaWP/skskskass.png) The unix philosophy is to have each tool do its job well. I saw an opportunity to combine three simple tools (zsh for scripting, gnuplot for charting, and jq for json querying) to make a live crypto charting program that has the advantage of being very resource unintensive (both ram and cpu). As can be seen in the screenshot, this script will launch a live chart of whatever crypto pair is wanted, with a configurable polling frequency. Developed for and on Linux, it will work on Windows and Mac OSX with the appropriate compatibility layer. Dependencies are Gnuplot with x11 output, curl, jq, and zsh. Here is the script: ```sh #!/bin/zsh while [[ $1 == -* ]]; do arg=${1#*=} case $1 in --symbol=*) symb=$arg ;; # ex. BTC-USDT --interval=*) kucoint=$arg ;; # ex. 1day --help|\ -h) sed -n '/case .1/,/esac/p' "$0" | grep -- '^\s\+\-.*)'; exit 0 ;; *) echo wrong option; exit 1 ;; esac shift done [[ $symb ]] || symb=BTC-USDT [[ $kucoint ]] || kucoint=30min per=1800 multfactor=2 [[ $kucoint == 4hour ]] && { per=14400; multfactor=6; } [[ $kucoint == 1day ]] && { per=86400; multfactor=30; } freq=8 time=`date +%s` timecopy=$time (( time -= (60 * 60 * 48 * multfactor) )) tznum=`date +%z` tz=${tznum:0:1}$(( (${tznum:1:2} * 3600) + (${tznum:3:2} * 60) )) url="https://api.kucoin.com/api/v1/market/candles?symbol${z/' '/}=$symb&type=$kucoint&startAt=$time&endAt=$timecopy" json=`curl -s $url` #echo $json > ~/candleszshtest.txt #json=$(< ~/candleszshtest.txt) function calcmvs { local line=$1 local items mult9=$(( 2.0 / (9 + 1) )) if ((line >= 9)); then items=($=maeligible[line]) if (( line > 9 )); then itemsprev1=($=maeligible[line-1]) ema9=$(( ((items[2] - itemsprev1[3]) * mult9) + itemsprev1[3] )) else added=0 for asdf in {$(( line-(9-1) ))..$line}; do items=($=maeligible[asdf]) (( added += items[2] )) done ema9=$(( added / 9 )) fi maeligible[line]=$items' '$ema9 lines[$items[1]]+=' '$ema9 fi mult20=$(( 2.0 / (20 + 1) )) if ((line >= 20)); then items=($=maeligible[line]) if (( line > 20 )); then itemsprev1=($=maeligible[line-1]) ema20=$(( ((items[2] - itemsprev1[4]) * mult20) + itemsprev1[4] )) else added=0 for asdf in {$(( line-(20-1) ))..$line}; do items=($=maeligible[asdf]) (( added += items[2] )) done ema20=$(( added / 20 )) fi maeligible[line]=$items' '$ema20 lines[$items[1]]+=' '$ema20 fi if ((line >= 50)); then items=($=maeligible[line]) if (( line > 50 )); then itemsprev50=($=maeligible[line-50]) itemsprev1=($=maeligible[line-1]) sma50=$(( ( ( itemsprev1[5] * 50 ) - itemsprev50[2] + items[2] ) / 50 )) else added=0 for asdf in {$(( line-(50-1) ))..$line}; do items=($=maeligible[asdf]) (( added += items[2] )) done sma50=$(( added / 50 )) fi maeligible[line]=$items' '$sma50 lines[$items[1]]+=' '$sma50 fi } function addeligible { asdf=$1 if (( per == 1800 )); then # prefer 1hour MAs here (( ${${=lines[asdf]}[1]} % 3600 == 1800 )) || return fi maeligible+=($asdf' '${${=lines[asdf]}[5]}) } # gnuplot expects time, open, low, high, close raw=`echo $json | jq -r '.data | .[] | [.[0,1,4,3,2]] | join(" ")' | tac` lines=(${(@f)raw}) for asdf in {1..$#lines}; do addeligible $asdf; done #date +%s.%N #benchmark for asdf in {1..$#maeligible}; do calcmvs $asdf; done #date +%s.%N #benchmark count=1 total=$#lines (( total % 2 == 0 )) || { echo expected even number lines; exit 1; } (( total = total / 2 )) (( count += total )) items=($=lines[count-1+total]) watch=($items[1] x $items[5]) cr_el=`tput cr; tput el` xrdb -merge <<< "gnuplot*exportselection: off" { cat <<- eof set terminal x11 noraise set grid set xdata time set timefmt "%s" set format x "%H:%M" set xrange [*:*] set yrange [*:*] set offsets 1,1,1,1 set palette defined (-1 "#b22222", 1 "#228b22") unset colorbox set style fill solid noborder eof while true; do watch[1]=${watch[1]%.*} (( watch[3] < items[3] )) && items[3]=$watch[3] (( watch[3] > items[4] )) && items[4]=$watch[3] items[5]=$watch[3] items[6]=; items[7]=; items[8]=; curmod=$(( watch[1] % per )) if (( $#lastmod > 0 && curmod <= lastmod )); then (( count++ )) items=($((items[1]+per)) $watch[3] $watch[3] $watch[3] $watch[3]) lines[count-1+total]=$items addeligible $((count-1+total)) fi lastmod=$curmod lines[count-1+total]=$items [[ ${${=maeligible[$#maeligible]}[1]} == $#lines ]] && { maeligible[$#maeligible]=${${=maeligible[$#maeligible]}[1]}${z/' '/}' '$items[5] calcmvs $#maeligible } cat <<- eof set title "${symb/-/\/} (kuco) interval $kucoint " . \ "freq ${freq}s : $watch[3]" \$dat << gnupeof ${(F)lines[count,count-1+total]} gnupeof plot \$dat using (\$1+$tz):2:3:4:5:(\$5 < \$2 ? -1 : 1) \ notitle with candlesticks palette \ , \$dat using (\$1+$tz):6 notitle with lines lc rgb "violet" \ , \$dat using (\$1+$tz):7 notitle with lines lc rgb "aquamarine" \ , \$dat using (\$1+$tz):8 notitle with lines lc rgb "#e9bd3d" eof echo -n 'Options: (q)uit, (f)req ' >&2 opt=; read -s -t $freq -k 1 opt print -nr- $cr_el >&2 case $opt in f) echo -n 'Enter a poll frequency in seconds: ' >&2 read newfreq [[ $newfreq =~ ^[0-9]+$ ]] && freq=$newfreq ;; q) break ;; esac oldwatchtime=${watch[1]} while true; do watch=(`curl -s "https://api.kucoin.com/api/v1/market/${z/' '/}orderbook/level1?symbol=$symb" | jq -r \ '[.data.time/1000, .code, .data.price | tostring] | join(" ")'`) (( $#watch == 3 )) && [[ $watch[2] == 200000 ]] && break sleep 8 done (( watch[1] - oldwatchtime > per )) && \ { echo exiting due to gap >&2; break; } done } | gnuplot ``` I am posting this on Hive before anywhere else.