#!/bin/bash

if [ $# -lt 3 ]; then
    echo "usage: ./mkhaskalimg.sh <dir> <cmd> <out>"
fi

dir="$1"
cmd="$2"
out="$3"

(cd "$dir" && tar czf ../haskalimg.tar.gz *)

header=$(cat <<EOF
#!/bin/bash
extdir="/tmp/haskalimg-\$(whoami)-\$(head -c8 /dev/urandom | xxd -p)"
mkdir "\$extdir"
tail -n +11 "\$0" | tar xz -C "\$extdir"
function finish {
    rm -rf "\$extdir"
}
trap finish EXIT
\$extdir/$2
exit
EOF
)

cat <(echo "$header") haskalimg.tar.gz > "$out"
rm haskalimg.tar.gz
chmod +x "$out"