1 \define{versionidplink} \versionid $Id$
3 \C{plink} Using the command-line connection tool \i{Plink}
5 \i{Plink} (PuTTY Link) is a command-line connection tool similar to
6 UNIX \c{ssh}. It is mostly used for \i{automated operations}, such as
7 making CVS access a repository on a remote server.
9 Plink is probably not what you want if you want to run an
10 \i{interactive session} in a console window.
12 \H{plink-starting} Starting Plink
14 Plink is a command line application. This means that you cannot just
15 double-click on its icon to run it and instead you have to bring up
16 a \i{console window}. In Windows 95, 98, and ME, this is called an
17 \q{MS-DOS Prompt}, and in Windows NT, 2000, and XP, it is called a
18 \q{Command Prompt}. It should be available from the Programs section
21 In order to use Plink, the file \c{plink.exe} will need either to be
22 on your \i{\c{PATH}} or in your current directory. To add the
23 directory containing Plink to your \c{PATH} environment variable,
24 type into the console window:
26 \c set PATH=C:\path\to\putty\directory;%PATH%
28 This will only work for the lifetime of that particular console
29 window. To set your \c{PATH} more permanently on Windows NT, 2000,
30 and XP, use the Environment tab of the System Control Panel. On
31 Windows 95, 98, and ME, you will need to edit your \i\c{AUTOEXEC.BAT}
32 to include a \c{set} command like the one above.
34 \H{plink-usage} Using Plink
36 This section describes the basics of how to use Plink for
37 interactive logins and for automated processes.
39 Once you've got a console window to type into, you can just type
40 \c{plink} on its own to bring up a usage message. This tells you the
41 version of Plink you're using, and gives you a brief summary of how to
45 \c PuTTY Link: command-line connection utility
47 \c Usage: plink [options] [user@]host [command]
48 \c ("host" can also be a PuTTY saved session name)
50 \c -V print version information and exit
51 \c -pgpfp print PGP key fingerprints and exit
52 \c -v show verbose messages
53 \c -load sessname Load settings from saved session
54 \c -ssh -telnet -rlogin -raw
55 \c force use of a particular protocol
56 \c -P port connect to specified port
57 \c -l user connect with specified username
58 \c -batch disable all interactive prompts
59 \c The following options only apply to SSH connections:
60 \c -pw passw login with specified password
61 \c -D [listen-IP:]listen-port
62 \c Dynamic SOCKS-based port forwarding
63 \c -L [listen-IP:]listen-port:host:port
64 \c Forward local port to remote address
65 \c -R [listen-IP:]listen-port:host:port
66 \c Forward remote port to local address
67 \c -X -x enable / disable X11 forwarding
68 \c -A -a enable / disable agent forwarding
69 \c -t -T enable / disable pty allocation
70 \c -1 -2 force use of particular protocol version
71 \c -4 -6 force use of IPv4 or IPv6
72 \c -C enable compression
73 \c -i key private key file for authentication
74 \c -noagent disable use of Pageant
75 \c -agent enable use of Pageant
76 \c -m file read remote command(s) from file
77 \c -s remote command is an SSH subsystem (SSH-2 only)
78 \c -N don't start a shell/command (SSH-2 only)
80 \c open tunnel in place of session (SSH-2 only)
82 Once this works, you are ready to use Plink.
84 \S{plink-usage-interactive} Using Plink for interactive logins
86 To make a simple interactive connection to a remote server, just
87 type \c{plink} and then the host name:
89 \c Z:\sysosd>plink login.example.com
91 \c Debian GNU/Linux 2.2 flunky.example.com
94 You should then be able to log in as normal and run a session. The
95 output sent by the server will be written straight to your command
96 prompt window, which will most likely not interpret terminal \i{control
97 codes} in the way the server expects it to. So if you run any
98 full-screen applications, for example, you can expect to see strange
99 characters appearing in your window. Interactive connections like
100 this are not the main point of Plink.
102 In order to connect with a different protocol, you can give the
103 command line options \c{-ssh}, \c{-telnet}, \c{-rlogin} or \c{-raw}.
104 To make an SSH connection, for example:
106 \c Z:\sysosd>plink -ssh login.example.com
109 If you have already set up a PuTTY saved session, then instead of
110 supplying a host name, you can give the saved session name. This
111 allows you to use public-key authentication, specify a user name,
112 and use most of the other features of PuTTY:
114 \c Z:\sysosd>plink my-ssh-session
115 \c Sent username "fred"
116 \c Authenticating with public key "fred@winbox"
117 \c Last login: Thu Dec 6 19:25:33 2001 from :0.0
120 (You can also use the \c{-load} command-line option to load a saved
121 session; see \k{using-cmdline-load}. If you use \c{-load}, the saved
122 session exists, and it specifies a hostname, you cannot also specify a
123 \c{host} or \c{user@host} argument - it will be treated as part of the
126 \S{plink-usage-batch} Using Plink for automated connections
128 More typically Plink is used with the SSH protocol, to enable you to
129 talk directly to a program running on the server. To do this you
130 have to ensure Plink is \e{using} the SSH protocol. You can do this
133 \b Use the \c{-ssh} option as described in
134 \k{plink-usage-interactive}.
136 \b Set up a PuTTY saved session that describes the server you are
137 connecting to, and that also specifies the protocol as SSH.
139 \b Set the Windows environment variable \i\c{PLINK_PROTOCOL} to the
142 Usually Plink is not invoked directly by a user, but run
143 automatically by another process. Therefore you typically do not
144 want Plink to prompt you for a user name or a password.
146 Next, you are likely to need to avoid the various interactive
147 prompts Plink can produce. You might be prompted to verify the host
148 key of the server you're connecting to, to enter a user name, or to
151 To avoid being prompted for the server host key when using Plink for
152 an automated connection, you should first make a \e{manual}
153 connection (using either of PuTTY or Plink) to the same server,
154 verify the host key (see \k{gs-hostkey} for more information), and
155 select Yes to add the host key to the Registry. After that, Plink
156 commands connecting to that server should not give a host key prompt
157 unless the host key changes.
159 To avoid being prompted for a user name, you can:
161 \b Use the \c{-l} option to specify a user name on the command line.
162 For example, \c{plink login.example.com -l fred}.
164 \b Set up a PuTTY saved session that describes the server you are
165 connecting to, and that also specifies the username to log in as
166 (see \k{config-username}).
168 To avoid being prompted for a password, you should almost certainly
169 set up \i{public-key authentication}. (See \k{pubkey} for a general
170 introduction to public-key authentication.) Again, you can do this
173 \b Set up a PuTTY saved session that describes the server you are
174 connecting to, and that also specifies a private key file (see
175 \k{config-ssh-privkey}). For this to work without prompting, your
176 private key will need to have no passphrase.
178 \b Store the private key in Pageant. See \k{pageant} for further
181 Once you have done all this, you should be able to run a remote
182 command on the SSH server machine and have it execute automatically
185 \c Z:\sysosd>plink login.example.com -l fred echo hello, world
190 Or, if you have set up a saved session with all the connection
193 \c Z:\sysosd>plink mysession echo hello, world
198 Then you can set up other programs to run this Plink command and
199 talk to it as if it were a process on the server machine.
201 \S{plink-options} Plink command line options
203 Plink accepts all the general command line options supported by the
204 PuTTY tools. See \k{using-general-opts} for a description of these
207 Plink also supports some of its own options. The following sections
208 describe Plink's specific command-line options.
210 \S2{plink-option-batch} \I{-batch-plink}\c{-batch}: disable all
213 If you use the \c{-batch} option, Plink will never give an
214 interactive prompt while establishing the connection. If the
215 server's host key is invalid, for example (see \k{gs-hostkey}), then
216 the connection will simply be abandoned instead of asking you what
219 This may help Plink's behaviour when it is used in automated
220 scripts: using \c{-batch}, if something goes wrong at connection
221 time, the batch job will fail rather than hang.
223 \S2{plink-option-s} \I{-s-plink}\c{-s}: remote command is SSH subsystem
225 If you specify the \c{-s} option, Plink passes the specified command
226 as the name of an SSH \q{\i{subsystem}} rather than an ordinary command
229 (This option is only meaningful with the SSH-2 protocol.)
231 \H{plink-batch} Using Plink in \i{batch files} and \i{scripts}
233 Once you have set up Plink to be able to log in to a remote server
234 without any interactive prompting (see \k{plink-usage-batch}), you
235 can use it for lots of scripting and batch purposes. For example, to
236 start a backup on a remote machine, you might use a command like:
238 \c plink root@myserver /etc/backups/do-backup.sh
240 Or perhaps you want to fetch all system log lines relating to a
243 \c plink mysession grep /~fred/ /var/log/httpd/access.log > fredlog
245 Any non-interactive command you could usefully run on the server
246 command line, you can run in a batch file using Plink in this way.
248 \H{plink-cvs} Using Plink with \i{CVS}
250 To use Plink with CVS, you need to set the environment variable
251 \i\c{CVS_RSH} to point to Plink:
253 \c set CVS_RSH=\path\to\plink.exe
255 You also need to arrange to be able to connect to a remote host
256 without any interactive prompts, as described in
257 \k{plink-usage-batch}.
259 You should then be able to run CVS as follows:
261 \c cvs -d :ext:user@sessionname:/path/to/repository co module
263 If you specified a username in your saved session, you don't even
264 need to specify the \q{user} part of this, and you can just say:
266 \c cvs -d :ext:sessionname:/path/to/repository co module
268 \H{plink-wincvs} Using Plink with \i{WinCVS}
270 Plink can also be used with WinCVS. Firstly, arrange for Plink to be
271 able to connect to a remote host non-interactively, as described in
272 \k{plink-usage-batch}.
274 Then, in WinCVS, bring up the \q{Preferences} dialogue box from the
275 \e{Admin} menu, and switch to the \q{Ports} tab. Tick the box there
276 labelled \q{Check for an alternate \cw{rsh} name} and in the text
277 entry field to the right enter the full path to \c{plink.exe}.
278 Select \q{OK} on the \q{Preferences} dialogue box.
280 Next, select \q{Command Line} from the WinCVS \q{Admin} menu, and type
281 a CVS command as in \k{plink-cvs}, for example:
283 \c cvs -d :ext:user@hostname:/path/to/repository co module
285 or (if you're using a saved session):
287 \c cvs -d :ext:user@sessionname:/path/to/repository co module
289 Select the folder you want to check out to with the \q{Change Folder}
290 button, and click \q{OK} to check out your module. Once you've got
291 modules checked out, WinCVS will happily invoke plink from the GUI for
294 \# \H{plink-whatelse} Using Plink with... ?