Reduce pdf file size using gs

#!/bin/bash # From http://scriptdemo.blogspot.com # to reduce pdf file size using gs with different optimization level # Usage: # pdfsmaller.sh in.pdf out.pdf [opt] # option: #            screen    (72dpi) #            ebook     (150dpi) #            printer    (300dpi) #            prepress (color preserving, 300dpi) # e.g., #            pdfsmaller.sh Big.pdf smaller.pdf ebook # save output to smaller.pdf # or        pdfsmaller.sh Big.pdf ebook                  # overwrite original Big.pdf # ref: http://milan.kupcevic.net/ghostscript-ps-pdf isOverWrite=0 if [ $# -eq 1 ]; then    inFile=$1    outFile=smaller_$1    opt="prepress"    isOverWrite=1 elif [ $# -eq 2 ]; then    inFile=$1    nf=`echo $2 | awk -F. '{print NF}'`    if [ ${nf} -eq 2 ]; then       outFile=$2       opt="prepress"    else       outFile=smaller_$1       opt=$2       isOverWrite=1    fi elif [ $# -eq 3 ]; then    inFile=$1    outFile=$2    opt=$3 else    sed -n '2,12p' pdfsmaller.sh    exit fi if [ ! -e "${inFile}" ]; then    echo "${inFile} not exist"    echo "gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/${opt} -dNOPAUSE \                   -dQUIET -dBATCH -sOutputFile=\"${outFile}\" \"${inFile}\""    exit else    eval "gs -sDEVICE=pdfwrite -dCompatibilityLevel=1.4 -dPDFSETTINGS=/${opt} -dNOPAUSE  \                  -dQUIET -dBATCH -sOutputFile=\"${outFile}\" \"${inFile}\"" fi [ ${isOverWrite} -eq 1 ] && mv "${outFile}" "${inFile}"