lftp script to mirror remote ftp site to local folder using multiple connections per file and parallel file downloads (for reference/cron jobs)

multisync.sh

#!/bin/bash
do_multisync() {
        remote_dir="private/files"
        local_dir="/root/i_drive/files"
    
        # remote host
        host="ftp.myremotehost.com"
        
        # username / password
        user="larry"
        pass="thisisnotmypassword"
        
        # number of connections / parts per file transfer
        partsperfile=10

        # number of parallel transfers at a time
        numfiles=2

        # get number of active multisync processes
        numprocs=`ps aux | grep  "[m]ultisync\$" | wc -l`
        if [[ $numprocs -gt 2 ]] ; then
                echo "Previous 'multisync' is still running. ($numprocs)"
                exit 1
        else
                echo "Running..."
                (
                        echo open ${host}
                        echo user ${user} ${pass}
                        echo mirror -v -c --use-pget-n=${partsperfile} --parallel=${numfiles} ${remote_dir} ${local_dir}
                        echo bye
                ) | lftp -f /dev/stdin
                exit 0
        fi
}

do_multisync >> /tmp/multisync.log &

mirror -v -c --use-pget-n=3 --parallel=2 . .