報錯如下：
sftp> put play.zip ./
Uploading play.zip to /opt/library/./play.zip
remote open("/opt/library/./play.zip"): Permission denied
原因：
sftp登錄以后當前所在目錄的owner不是sftp登錄者，也就是說當前目錄沒有write權限，so修改權限，再put上傳。如下：
$ sudo chown xuyuzhu -R ./ # ssh登錄以后修改目錄owner $ exit 登出 $ sftp xuyuzhu@192.168.63.9 # 重新登錄sftp xuyuzhu@192.168.63.9's password: Connected to 192.168.63.9. sftp> cd /opt # 進入要上傳的目錄 sftp> put play.zip # 上傳 Uploading play.zip to /opt/library/play.zip play.zip 100% 74MB 10.6MB/s 00:07