fetch.sh

#!/bin/bash
cat list | while read -r file url; do
  post=$(basename "$file")
  image=$(basename "$url")
  outfile="${post%.*}.${image##*.}"
  if [ -f ${outfile} ] ; then
    count=$( find . -name "${post%.*}*" 2> /dev/null | wc -l )
    outfile="${post%.*}-${count}.${image##*.}"
  fi
  wget ${url} -O ${outfile}
done