thumbalizr

#!/bin/bash                                                             
width=""                                                                
height=""                                                               
prepend=""                                                              
append=""                                                               
while getopts 'h:w:p:a:' OPTION                                         
do                                                                      
  case $OPTION in                                                       
  w)    width="$OPTARG"                                                 
        ;;                                                              
  h)    height="$OPTARG"                                                
        ;;                                                              
  p)    prepend="$OPTARG"                                               
        ;;                                                              
  a)    append="$OPTARG"                                                
        ;;                                                              
  ?)    printf "Usage: %s: [-w width] [-h height] [-p prepend_to_filename] [-a append_to_filename] [FILE]... FILE\n" $(basename $0) >&2                                                                                                                   
        exit 2                                                                                                               
        ;;                                                                                                                   
  esac                                                                                                                       
done                                                                                                                         
shift $(($OPTIND - 1))                                                                                                       

if [ $width ]
then         
        dims="$width"
else                 
        if [ -z $height ]
        then             
                printf "Usage: %s: [-w width] [-h height] [-p prepend_to_filename] [-a append_to_filename] [FILE]... FILE\n" $(basename $0) >&2
                exit 2
        fi
fi

if [ $height ]
then
        dims="${dims}x${height}"
fi

for file in $@
do
        echo "Processing $file..."
        newfile=$(basename $file)
        dir="$(dirname $file)/"

        if [ $append ]
        then
                newfile="$dir${newfile%.*}$append.${newfile##*.}"
        fi

        if [ $prepend ]
        then
                newfile="$dir$prepend$(basename $newfile)"
        fi

        $(convert -thumbnail $dims $file $newfile)
done