Bash script for downloading VSCode extensions faster

vsceext.bash

#!/usr/bin/env bash

if [[ $# -lt 2 ]]; then
  echo "ERR: Missing arguments."
  # requires an SSH server
  # arg1: {package}.{extension}@{version}
  # arg2 {host}
  exit 1
fi

host=$2
tmp=${1#*.}
version=${1#*@}
publisher=${1%%.*}
extension=${tmp%@*}

file=$publisher.$extension-$version.vsix
url=http://$publisher.gallery.vsassets.io/_apis/public/gallery/publisher/$publisher/extension/$extension/$version/assetbyname/Microsoft.VisualStudio.Services.VSIXPackage

echo "INF: Connecting to host..."
rdir=`ssh $host "mktemp -d"`
ssh $host '
cd '$rdir'
echo "INF: Fetching extension..."
wget -q '$url'
size=`du -h Microsoft.VisualStudio.Services.VSIXPackage | cut -f1`
echo "INF: Original size is ${size}"
echo "INF: Unpacking extension..."
unzip -q Microsoft.VisualStudio.Services.VSIXPackage
rm Microsoft.VisualStudio.Services.VSIXPackage
echo "INF: Compressing extension..."
XZ_OPTS=-9 tar cfJ etx *
size=`du -h etx | cut -f1`
echo "INF: Compressed size is ${size}"
'

back=$PWD
ldir=`mktemp -d`
cd $ldir
echo "INF: Downloading extension..."
scp -q $host:$rdir/etx etx
echo "INF: Unpacking extension..."
tar xfJ etx
rm etx
echo "INF: Compressing extension..."
zip -rq $file *
cp $file $back
echo "INF: Ready at $back/$file"