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:
#!/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.
