procimage

linux脚本编程的例子

# Set up the defaults
width=1
colour='-color grey'
usage="Usage: $0 [-s N] [-w N] [-c S] imagefile..."

# Initialise the pipeline components
standardise=' | ppmquant -quiet 256 | ppmtogif -quiet'

while getopts ":s:w:c:" opt; do
    case $opt in
      s  ) size=$OPTARG
           scale=' | pnmscale -quiet -xysize $size $size' ;;
      w  ) width=$OPTARG
           border=' | pnmmargin $colour $width' ;;
      c  ) colour="-color $OPTARG"
           border=' | pnmmargin $colour $width' ;;
      \? ) echo $usage
           exit 1 ;;
    esac
done

shift $(($OPTIND - 1))

if [ -z "$@" ]; then
    echo $usage
    exit 1
fi

# Process the input files
for filename in "$@"; do
    case $filename in
        *.gif ) convert=giftopnm  ;;

        *.tga ) convert=tgatoppm  ;;

        *.xpm ) convert=xpmtoppm  ;;

        *.pcx ) convert=pcxtoppm  ;;

        *.tif ) convert=tifftopnm  ;;

        *.jpg ) convert=djpeg ;;

            * ) echo "$0: Unknown filetype '${filename##*.}'"
                exit 1;;
    esac

    outfile=${filename%.*}.new.gif

    eval $convert $filename $scale $border $standardise > $outfile

done