if [ $# -gt 1 ]; then echo "Only one file can be shared"; exit 1; fi
if [ $# != 0 ]; then PARAMS="$PARAMS --es file `realpath $1`"; fi
if [ $# -gt 1 ]; then echo "Only one file can be shared"; exit 1; fi
if [ $# != 0 ]; then PARAMS="$PARAMS --es file `realpath $1`"; fi