概述：
SFTP是Secure File Transfer Protocol的缩写，即安全的文件传输协议，端口号默认为22，相比较FTP，SFTP可以为传输文件提供一种安全的加密方法，由于这种传输方式使用了加密/解密技术，所以传输效率比普通的FTP要低得多，如果您对网络安全性要求更高时，可以使用SFTP代替FTP。
使用及样例：
1、连接方法 sftp [user@]host [port] 输入密码后出现连接成功的提示符
[d:~]$ sftp alen@192.168.56.1 1023 连接SFTP
Connecting to 192.168.56.1:1023...
Connection established.
To escape to local shell, press 'Ctrl+Alt+]'.
Your current local directory is
D:Documents and SettingsAlen.LiuDocumentsNetSarangXshellSessions
Type `help' to browse available commnands.
sftp:/home/alen> 2、查看帮助，得到该工具的命令
sftp:/home/alen> help --->查看帮助，如果查看某一个具体的命令的帮助信息，可以使用help 命令
bye finish your SFTP session
cd change your remote working directory
clear clear screen
exit finish your SFTP session
explore explore your local directory
get download a file from the server to your local machine
help give help
lcd change and/or print local working directory
lls list contents of a local directory
lpwd print your local working directory
ls list contents of a remote directory
mkdir create a directory on the remote server
mv move or rename a file on the remote server
put upload a file from your local machine to the server
pwd print your remote working directory
quit finish your SFTP session
rename move or rename a file on the remote server
rm delete a file
rmdir remove a directory on the remote server
sftp:/home/alen> 其中，指令前带有l的命令，表示是对本地的操作，其他的则是对远端的操作。该工具的命令相对简单，故不对每一个命令举例，具体可以自己研究。
sftp:/home/alen> lls --->列出本地文件列表
04/07/2017 08:39? <DIR> .
04/07/2017 08:39? <DIR> ..
04/07/2017 08:39? 6 file.txt
04/07/2017 08:39? 9224 mysql57-community-release-el7-9.noarch.rpm
sftp:/home/alen> put mysql57-community-release-el7-9.noarch.rpm . --->上传本地文件到远端目录
sftp: cannot open e:userdata to read
Uploading mysql57-community-release-el7-9.noarch.rpm to remote:/home/alen/mysql57-community-release-el7-9.noarch.rpm
sftp: sent 9.00 KB in 0.05 seconds
sftp:/home/alen> ls --->列出远端目录下文件列表
drwx------ 20 alen alen 4096 Apr 7 16:41 .
drwxr-xr-x 5 root root 38 Mar 29 16:30 ..
drwxr-xr-x 5 alen alen 51 Dec 12 14:38 .mozilla
-rw-r--r-- 1 alen alen 18 Mar 6 2015 .bash_logout
-rw-r--r-- 1 alen alen 193 Mar 6 2015 .bash_profile
-rw-r--r-- 1 alen alen 231 Mar 6 2015 .bashrc
drwxr-xr-x 16 alen alen 4096 Apr 6 15:26 .config
drwx------ 10 alen alen 4096 Dec 12 14:47 .cache
drwxr-xr-x 2 alen alen 54 Dec 15 17:40 Desktop
drwxr-xr-x 2 alen alen 6 Dec 12 14:37 Downloads
drwxr-xr-x 2 alen alen 6 Dec 12 14:37 Templates
drwxr-xr-x 2 alen alen 6 Dec 12 14:37 Public
drwxr-xr-x 2 alen alen 6 Dec 12 14:37 Documents
drwxr-xr-x 2 alen alen 6 Dec 12 14:37 Music
drwxr-xr-x 2 alen alen 6 Dec 12 14:37 Pictures
drwxr-xr-x 2 alen alen 6 Dec 12 14:37 Videos
-rw------- 1 alen alen 1864 Apr 6 14:54 .ICEauthority
drwx------ 3 alen alen 18 Dec 12 14:37 .local
-rw------- 1 alen alen 16 Dec 12 14:37 .esd_auth
drwx------ 3 alen alen 19 Dec 12 14:38 .gnome2
drwx------ 2 alen alen 6 Dec 12 14:38 .gnome2_private
-rw------- 1 alen alen 6532 Apr 7 11:08 .bash_history
drwxrwxr-x 2 alen alen 87 Mar 27 17:15 test
drwxrwxr-x 2 alen alen 18 Mar 24 16:53 test1
drwxrwxr-x 2 alen alen 100 Mar 27 17:13 test11
-rw------- 1 alen alen 4408 Apr 6 14:49 .viminfo
-rw-rw-r-- 1 alen alen 178 Mar 31 15:52 file.tar.gz
drwxrwxr-x 2 alen alen 55 Apr 1 16:05 bash
-rw-rw-r-- 1 alen alen 9224 Apr 7 16:41 mysql57-community-release-el7-9.noarch.rpm --->在这里可以看到上面上传的文件
sftp:/home/alen>