backup.sh

backup.sh

#!/bin/bash
set -e

# backup.sh
# makes a copy of a file, appending a datestamp and incrementing a counter
# if it's needed.
#
# ie, running this 3 times:
# backup.sh /foo/bar.qux /foo/backups
# will create:
# /foo/backups/bar.2017-06-20.qux
# /foo/backups/bar.2017-06-20.1.qux
# /foo/backups/bar.2017-06-20.2.qux


if [ $# -ne 2 ]
  then
    echo "2 arguments required: source filename and target directory"
    echo "backup.sh /foo/bar/qux.sqlite /foobackups"
    exit 1
fi

source=$1
targetdir=$2

path=$(basename "$source")
extension="${path##*.}"
filename="${path%.*}"

targetfilename=$filename.$(date +%F)

mkdir -p $targetdir

if [[ -e $targetdir/$targetfilename.$extension ]] ; then
    i=1
    while [[ -e $targetdir/$targetfilename.$i.$extension ]] ; do
        let i++
    done
    targetfilename=$targetfilename.$i
fi
cp $source $targetdir/$targetfilename.$extension
echo "Backed up $source to $targetdir/$targetfilename.$extension"
exit 0