if [[ $# != 1 ]]
then
  echo "Usage: $0 [.tex file]"
  exit 1
fi

PRACA=$1
if ! [[ -f $PRACA ]]
then
  echo "No such file: $PRACA"
  exit 1
fi

threshold=1
while true
do
  if (($(date +"%s")- $(stat --format="%Y" $PRACA) < $threshold))
  then
    echo "updating"
    pdflatex $PRACA
  else
    sleep 0.2
  fi
done