Back up Subversion repositories incrementally (easily run from cron).

svnbackup.sh

#!/bin/bash
# Back up Subversion repositories. Run from cron.
# Somewhat ironic that I post this to github ...
svndir=$HOME/svn
destdir=$HOME/svnbackups
dumpcmd="svnadmin dump --quiet --incremental"
repos=`find "$svndir" -maxdepth 1 -mindepth 1 -type d -exec basename {} \;`

for repo in $repos; do
    oldend=`ls -1t $destdir/$repo.*.*.* 2>/dev/null | head -n1 | cut -d. -f 3`
    head=`svn info "file:///$svndir/$repo" | grep ^Revision | cut -d' ' -f 2`
    start=$(( ${oldend:-0} + 1 ))

    # Skip this repository if there are no new revisions since last backup
    if [ $start -ge $head ]; then continue; fi
    echo "Backing up repo $repo revisions $start - $head ..."

    # Set up temporaries
    tempdir=`mktemp -d "$repo.$start.$head.XXXXXX"` || exit 1
    temptar=`mktemp    "$repo.$start.$head.XXXXXX"` || exit 1
    destfile="$repo.$start.$head.`date -Iseconds`.svndump"

    # Do the backup
    cp "$svndir/$repo.access" "$svndir/$repo.passwd" $tempdir/ &&
    $dumpcmd -r$start:$head "$svndir/$repo" > "$tempdir/$destfile" &&
    tar -C $tempdir -zcf $temptar . &&
    mv $temptar "$destdir/$repo.$start.$head.tar.gz" &&
    rm -rf $tempdir &&
    echo "... done" || echo '... failed!'
done