-- doesn't work here

Signed-off-by: Anirudh Oppiliappan <[e-mail]>

shlide

···
     slides=("$slides_dir"/[0-9]*.txt)
     i=0
     while true; do
-        if [ "$i" -gt "$((${#slides[@]}--))" ]; then
+        if [ "$i" -gt "$((${#slides[@]} - 1))" ]; then
             printf '\e[?25h'
             exit;
         fi