rsync pass multiple exclude from $@

Question

I'm trying to make a wrapper around my rsync command to reuse code. I need to pass the source folder, the target folder and then any number of excluded directories. Here is what I have with the logs; basically I am building my multiple rsync's --exclude params from my "vararg" param. There may be a better way but I found that one ok enough.

function run_backup(){
    source="$1"
    target="/backups/unraid$2"
    #Copying $source into remote folder $target
# Building my exclude params
if [ $# -ge 3 ]; then
    excludes="--exclude '$3'"
    while shift && [ -n "$3" ]; do
        echo $excludes
        excludes="${excludes} --exclude '$3'"
    done
else
    excludes = "--exclude '/tmp'" # Dummy exclude; I'll handle this case later
fi
echo $excludes

# Creating folder because rsync crash otherwise n some case
ssh -p 22 -i /home/backup/.ssh/mykey unraid@94.23.49.55 "mkdir -p $target"

# Executing the copy
set -e
sudo rsync -azvh \
    -e "ssh  -p 22-i /home/backup/.ssh/mykey "\
    --progress \
    --delete \
    $excludes \
    $source \
    unraid@69.69.69.69:$target

}
mkdir -p /tmp/dummy
echo "dummy" > /tmp/dummy/save-ignored-1
echo "dummy" > /tmp/dummy/save-ignored-2
echo "dummy" > /tmp/dummy/save-test
run_backup /tmp/dummy/ /dummy /tmp/dummy/save-ignored-1 /tmp/dummy/save-ignored-2 /tmp/toto /tmp/tata /tmp/tutu #TODO

--exclude '/tmp/dummy/save-ignored-1'
--exclude '/tmp/dummy/save-ignored-1' --exclude '/tmp/dummy/save-ignored-2'
--exclude '/tmp/dummy/save-ignored-1' --exclude '/tmp/dummy/save-ignored-2' --exclude '/tmp/toto'
--exclude '/tmp/dummy/save-ignored-1' --exclude '/tmp/dummy/save-ignored-2' --exclude '/tmp/toto' --exclude '/tmp/tata'
--exclude '/tmp/dummy/save-ignored-1' --exclude '/tmp/dummy/save-ignored-2' --exclude '/tmp/toto' --exclude '/tmp/tata' --exclude '/tmp/tutu'
++ ssh -p 22-i /home/backup/.ssh/mykey unraid@69.69.69.69 'mkdir -p /backups/unraid/dummy'
++ sudo rsync -azvh -e 'ssh  -p 22 -i /home/backup/.ssh/mykey' --progress --delete --exclude ''\''/tmp/dummy/save-ignored-1'\''' --exclude ''\''/tmp/dummy/save-ignored-2'\''' --exclude ''\''/tmp/toto'\''' --exclude ''\''/tmp/tata'\''' --exclude ''\''/tmp/tutu'\''' /tmp/dummy/ unraid@94.23.49.55:/backups/unraid/dummy

We can see the $excludes var contain exactly what I want; but bash is doing some magic on it when I pass it to rsync. And I have no idea how to avoid that. I guess it has to do with expansion, but I could not find a problem similar to mine or the revelant doc.

EDIT: code after first answer:

function run_backup(){
    excludes=()
    if [ $# -ge 3 ]; then
        echo $3
        excludes+=(--exclude $3)
        while shift && [ -n "$3" ]; do
            echo $3
            excludes+=(--exclude $3)
        done
    else
        excludes+=(--exclude /tmp)
    fi
    set -x
    echo "${excludes[@]}"
}
run_backup /tmp/dummy/ /dummy "/tmp/dummy/save-ignored" "/tmp/dummy/save non'standard ignored" /tmp/toto /tmp/tata /tmp/tutu

But it won't work for string containing quotes (at least simple quotes)

/tmp/dummy/save-ignored
/tmp/dummy/save non'standard ignored
/tmp/toto
/tmp/tata
/tmp/tutu
++ echo --exclude /tmp/dummy/save-ignored --exclude /tmp/dummy/save 'non'\''standard' ignored --exclude /tmp/toto --exclude /tmp/tata --exclude /tmp/tutu
--exclude /tmp/dummy/save-ignored --exclude /tmp/dummy/save non'standard ignored --exclude /tmp/toto --exclude /tmp/tata --exclude /tmp/tutu

EDIT 2: Useless; just keeping it for history A test with all quotations possibilities:

run_backup(){
    excludes=()
    excludes2=()
    excludes3=()
    if [ $# -ge 3 ]; then
        echo $3
        excludes+=(--exclude $3)
        excludes2+=(--exclude "$3")
        excludes3+=(--exclude "\"$3\"")
        while shift && [ -n "$3" ]; do
            echo $3
            excludes+=(--exclude $3)
            excludes2+=(--exclude "$3")
            excludes3+=(--exclude "\"$3\"")
        done
    else
        excludes+=(--exclude /tmp)
    fi
    set -x
    echo "${excludes[@]}"
    echo "${excludes2[@]}"
    echo "${excludes3[@]}"
     sudo rsync -azvh \
        --dry-run \
        "${excludes[@]}" \
        --dry-run \
        "${excludes2[@]}" \
        --dry-run \
        "${excludes3[@]}" \
        --dry-run \
        ${excludes[@]} \
        --dry-run \
        ${excludes2[@]} \
        --dry-run \
        ${excludes3[@]} \
        /tmp \
        unraid@69.69.69.69:/tmp
}
run_backup "/tmp/dummy/" "/dummy" "/tmp/dummy/save non'standard" "/tmp/toto"

++ echo --exclude /tmp/dummy/save 'non'\''standard' --exclude /tmp/toto
--exclude /tmp/dummy/save non'standard --exclude /tmp/toto
++ echo --exclude '/tmp/dummy/save non'\''standard' --exclude /tmp/toto
--exclude /tmp/dummy/save non'standard --exclude /tmp/toto
++ echo --exclude '"/tmp/dummy/save non'\''standard"' --exclude '"/tmp/toto"'
--exclude "/tmp/dummy/save non'standard" --exclude "/tmp/toto"
++ sudo rsync -azvh --dry-run --exclude /tmp/dummy/save 'non'\''standard' --exclude /tmp/toto --dry-run --exclude '/tmp/dummy/save non'\''standard' --exclude /tmp/toto --dry-run --exclude '"/tmp/dummy/save non'\''standard"' --exclude '"/tmp/toto"' --dry-run --exclude /tmp/dummy/save 'non'\''standard' --exclude /tmp/toto --dry-run --exclude /tmp/dummy/save 'non'\''standard' --exclude /tmp/toto --dry-run --exclude '"/tmp/dummy/save' 'non'\''standard"' --exclude '"/tmp/toto"' /tmp unraid@69.69.69.69:/tmp

Screenshot of my test with better formated outputs:

Answer 1

Use an array instead of a string.

For example:

opt=()
opt+=(--exclude "first")
opt+=(--exclude "another one")
set -x
echo "${opt[@]}"

This will handle spaces correctly (output):

+ echo --exclude first --exclude 'another one'