resize-images

#!/usr/bin/env sh
#
# Copyright 2017 Thomas Heinemann
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# Variable initialization
SOURCE="$PWD"
TARGET="Publish"

size="2048x1536"

pushd () {
    command pushd "$@" > /dev/null
}

popd () {
    command popd "$@" > /dev/null
}

pushd "$PWD"

abort() {
    popd
    exit 1
}

checkSize() {
    size=$1
    if ! ( echo $size | grep -P "^[0-9]+x[0-9]+$" -q )
    then
        >&2 echo "$size is not a valid size specification."
        >&2 echo "Must be of format <WIDTH>x<HEIGHT>, e.g. 2048x1536"
        abort
    fi

}

printHelpAndExit() {
    echo "$(basename $0) - Resize several images in a batch"
    echo ""
    echo "Usage: $(basename $0) [-S SOURCE] [-T TARGET] [-f FILE] [-s SIZE] [-h]"
    echo ""
    echo "Options:"
    echo " -S SOURCE   Specifies the source folder to read from. Default is the current directory."
    echo " -T TARGET   Specifies the target directory. Default is \"Publish\""
    echo " -f FILE     Specifies a file to process. If not given, <TARGET>.txt (from the target name, see above)"
    echo "             is used if it exists; if this file does not exist, resize.txt is used. If resize.txt file does"
    echo "             not exist either, then all files matching *.JPG or *.jpg are processed."
    echo " -f          Prints this help text and exits."
    echo " -s SIZE     Resizes the images to the specified size. SIZE must be in the form <WIDTH>x<HEIGHT>."
    echo "             Default is 2048x1536."

    popd
    exit $1
}

while getopts f:s:S:T:vh opt
do
    case $opt in
        f)  customFileParam=$OPTARG
            customFile=$(realpath $customFileParam);;
        s)  size=$OPTARG
            checkSize $size;;
        S)  SOURCE=$OPTARG;;
        T)  TARGET=$OPTARG;;
        v)  echo "Option -v is not supported yet.";;
        h)  printHelpAndExit 0;;
        ?)  printHelpAndExit 1;;
    esac
done

cd "$SOURCE"
if [ $? -ne 0 ]
then
    echo Beende...
    abort
fi

if [ ! -d "$TARGET" ]
then
    mkdir "$TARGET"
    if [ $? -ne 0 ]
    then
	echo Beende...
	abort
    fi
fi

if [ $customFileParam ]
then
    if [ -f $customFile ]
    then
        FILES=$(cat $customFile)
    else
        >&2 echo $customFileParam does not exist or is not a file.
        abort
    fi
elif [ -f $TARGET.txt ]
then
    FILES=$(cat $TARGET.txt)
elif [ -f resize.txt ]
then
    FILES=$(cat resize.txt)
else
    FILES="*.JPG *.jpg"
fi

for i in $FILES
do
    echo Verkleinere $i
    convert $i -resize $size $TARGET/$i
done

popd