Telnet

Description

Task to automate a remote telnet session. The task uses nested <read> to indicate strings to wait for, and <write> tags to specify text to send.

If you do specify a userid and password, the system will assume a common unix prompt to wait on. This behavior can be easily over-ridden.

Note: This task depends on external libraries not included in the Apache Ant distribution. See Library Dependencies for more information.

Parameters

Attribute Values Required
userid the login id to use on the telnet server. Only if password is specified
password the login password to use on the telnet server. Only if userid is specified
server the address of the remote telnet server. Yes
port the port number of the remote telnet server. Defaults to port 23. No
initialCR send a cr after connecting ("yes"). Defaults to "no". No
timeout set a default timeout to wait for a response. Specified in seconds. Default is no timeout. No

Nested Elements

The commands to send to the server, and responses to wait for, are described as nested elements.

read

declare (as a text child of this element) a string to wait for. The element supports the timeout attribute, which overrides any timeout specified for the task as a whole. It also has a string attribute, which is an alternative to specifying the string as a text element.

Always declare an opening and closing <read> element to ensure that statements are not sent before the connection is ready, and that the connection is not broken before the final command has completed.

write

describes the text to send to the server. The echo boolean attribute controls whether the string is echoed to the local log; this is "true" by default

Examples

A simple example of connecting to a server and running a command. This assumes a prompt of "ogin:" for the userid, and a prompt of "assword:" for the password. 
<telnet userid="bob" password="badpass" server="localhost">
   <read>/home/bob</read>
   <write>ls</write>
   <read string="/home/bob"/>
</telnet>
This task can be rewritten as: 
<telnet server="localhost">
   <read>ogin:</read>
   <write>bob</write>
   <read>assword:</read>
   <write>badpass</write>
   <read>/home/bob</read>
   <write>ls</write>
   <read>/home/bob</read>
</telnet>
A timeout can be specified at the <telnet> level or at the <read> level. This will connect, issue a sleep command that is suppressed from displaying and wait 10 seconds before quitting. 
<telnet userid="bob" password="badpass" server="localhost" timeout="20">
   <read>/home/bob</read>
   <write echo="false">sleep 15</write>
   <read timeout="10">/home/bob</read>
</telnet>
The task can be used with other ports as well: 
<telnet port="80" server="localhost" timeout="20">
   <read/>
   <write>GET / http/0.9</write>
   <write/>
   <read timeout="10">&lt;/HTML&gt;</read>
</telnet>

To use this task against the WinNT telnet service, you need to configure the service to use classic authentication rather than NTLM negotiated authentication. This can be done in the Telnet Server Admin app: select "display/change registry settings", then "NTLM", then set the value of NTLM to 1.