lftp是一個很穩定很好用的命令行ftp工具。get命令用來下載文件，卻無法下載文件夾。如果要上傳和下載文件夾，就要用到mirror命令了。
簡單示例：
下載：mirror rdir ldir // 將遠程目錄rdir下載到本地目錄ldir
上傳：mirror -R ldir rdir // 將本地目錄ldir上傳到遠程目錄rdir
下面是help mirror的幫助信息：
lftp :~> help mirror Usage: mirror [OPTS] [remote [local]] Mirror specified remote directory to local directory -c, --continue continue a mirror job if possible -e, --delete delete files not present at remote site --delete-first delete old files before transferring new ones -s, --allow-suid set suid/sgid bits according to remote site --allow-chown try to set owner and group on files --ignore-time ignore time when deciding whether to download -n, --only-newer download only newer files (-c won't work) -r, --no-recursion don't go to subdirectories -p, --no-perms don't set file permissions --no-umask don't apply umask to file modes -R, --reverse reverse mirror (put files) -L, --dereference download symbolic links as files -N, --newer-than=SPEC download only files newer than specified time -P, --parallel[=N] download N files in parallel -i RX, --include RX include matching files -x RX, --exclude RX exclude matching files RX is extended regular expression -v, --verbose[=N] verbose operation --log=FILE write lftp commands being executed to FILE --script=FILE write lftp commands to FILE, but don't execute them --just-print, --dry-run same as --script=- When using -R, the first directory is local and the second is remote. If the second directory is omitted, basename of first directory is used. If both directories are omitted, current local and remote directories are used.