Convert an image file into an ascii art and show it in the terminal. This script requires netpbm.

aa.sh

#!/usr/bin/env bash

if [ $# -ne 1 ]; then
  exit 1
fi

filetype=`file -b "$1" | awk '{print $1}'`

if [ x$filetype == x ]; then
  msg="ERROR: Could not determine the file type of \"$1\""
  echo $msg; logger $msg
  exit 1
fi

opt='-contrast 0 -bright 0 -inverse'

case "$filetype" in
  'JPEG') jpegtopnm "$1" | aview $opt ;;
  'PNG' ) pngtopnm "$1" | aview $opt ;;
  * )
    anytopnm "$1" | aview $opt
    if [ $? -ne 0 ]; then
      msg="ERROR: Cannot handle \"$filetype\"."
      echo $msg; logger $msg
      exit 1
    fi
    ;;
esac

exit 0