/usr/bin/slideshow is in racket 6.3-1.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 | #!/bin/sh
# This script was created by make-mred-launcher
# {{{ bindir
bindir="/usr/bin"
# }}} bindir
# {{{ librktdir
librktdir="/usr/lib/racket"
# }}} librktdir
# Find X flags and shift them to the front
findxend() {
 oneargflag=''
 case "$1" in
  -display)
     oneargflag="$1"
     xa="$2"
   ;;
  -geometry)
     oneargflag="$1"
     xb="$2"
   ;;
  -bg | -background)
     oneargflag="$1"
     xc="$2"
   ;;
  -fg | -foregound)
     oneargflag="$1"
     xd="$2"
   ;;
  -font)
     oneargflag="$1"
     xe="$2"
   ;;
  -name)
     oneargflag="$1"
     xf="$2"
   ;;
  -selectionTimeout)
     oneargflag="$1"
     xg="$2"
   ;;
  -title)
     oneargflag="$1"
     xh="$2"
   ;;
  -xnllanguage)
     oneargflag="$1"
     xi="$2"
   ;;
  -xrm)
     oneargflag="$1"
     xj="$2"
   ;;
  -iconic)
    xk=yes
  ;;
  -rv | -reverse)
    xl=yes
  ;;
  +rv)
    xm=yes
  ;;
  -synchronous)
    xn=yes
  ;;
  -singleInstance)
    xo=yes
  ;;
  *)
    exec "${librktdir}/gracket"  ${xa+"-display"} ${xa+"$xa"} ${xb+"-geometry"} ${xb+"$xb"} ${xc+"-bg"} ${xc+"$xc"} ${xd+"-fg"} ${xd+"$xd"} ${xe+"-font"} ${xe+"$xe"} ${xf+"-name"} ${xf+"$xf"} ${xg+"-selectionTimeout"} ${xg+"$xg"} ${xh+"-title"} ${xh+"$xh"} ${xi+"-xnllanguage"} ${xi+"$xi"} ${xj+"-xrm"} ${xj+"$xj"} ${xk+"-iconic"} ${xl+"-rv"} ${xm+"+rv"} ${xn+"-synchronous"} ${xo+"-singleInstance"} -N "$0" '-I' 'scheme/gui/init' '-l-' 'slideshow/start.rkt'  ${1+"$@"}
  ;;
 esac
 shift
 if [ "$oneargflag" != '' ] ; then
   if [ "${1+n}" != 'n' ] ; then echo $0: missing argument for standard X flag $oneargflag ; exit 1 ; fi
   shift
 fi
 findxend ${1+"$@"}
}
findxend ${1+"$@"}
 |