org.das2.util.Expect

Provides similar functions as the Unix Expect tool.
There are two ways to create an Expect object: a constructor that takes an {@link InputStream} handle and {@link OutputStream} handle; or spawning a process by providing a command String.

The API is loosely based on Perl Expect library:
http://search.cpan.org/~rgiersig/Expect-1.15/Expect.pod
If you are not familiar with the Tcl version of Expect, take a look at:
http://oreilly.com/catalog/expect/chapter/ch03.html

Expect uses a thread to convert InputStream to a SelectableChannel; other than this, no multi-threading is used.
A call to expect() will block for at most timeout seconds. Expect is not designed to be thread-safe, in other words, do not call methods of the same Expect object in different threads.

Expect( java.io.InputStream input, java.io.OutputStream output )

before

String before the last match(if there was a match), updated after each expect() call

match

String representing the last match(if there was a match), updated after each expect() call

isSuccess

Whether the last match was successful, updated after each expect() call

RETV_TIMEOUT

RETV_EOF

RETV_IOEXCEPTION

byteToPrintableString

Parameters

Returns:

bytesToPrintableString

Static method used for convert byte array to string, each byte is converted to an ASCII character, if the byte represents a control character, it is replaced by a printable caret notation http://en.wikipedia.org/wiki/ASCII , or an escape code if possible.

Parameters

Returns:

close

The OutputStream passed to Expect constructor is closed; the InputStream is not closed (there is no need to close the InputStream).
It is suggested that this method be called after the InputStream has come to EOF. For example, when you connect through SSH, send an "exit" command first, and then call this method.

When this method is called, the thread which write to the sink of the pipe will end.

Returns:

expect

Convenience method, same as calling {@link #expect(int, Object...) expect(default_timeout, patterns)}

Parameters

Returns:

expectEOF

Convenience method, internally it calls {@link #expect(int, List) expect(timeout, new ArrayList<Pattern>())}. Given an empty list, {@link #expect(int, List)} will not perform any regex matching, therefore the only conditions for it to return is EOF or timeout (or IOException). If EOF is detected, {@link #isSuccess} and {@link #before} are properly set.

Parameters

Returns:

expectEOFOrThrow

Throws checked exceptions when expectEOF was not successful.

Parameters

Returns:

expectOrThrow

This method calls {@link #expect(int, Object...) expect(timeout, patterns)}, and throws checked exceptions when expect was not successful. Useful when you want to simplify error handling: for example, when you send a series of commands to an SSH server, you expect a prompt after each send, however the server may die or the prompt may take forever to appear, you would want to skip the following commands if those occurred. In such a case this method will be handy.

Parameters

Returns:

forwardInputStreamTo

While performing expect operations on the InputStream provided, duplicate the contents obtained from InputStream to a PrintStream (you can use System.err or System.out). DO NOT call this function while there are live Expect objects as this may cause the piping thread to end due to unsynchronized code; if you need this feature, add the following to both {@link #inputStreamToSelectableChannel(InputStream)} and {@link #forwardInputStreamTo(PrintStream)}:

 
 	synchronized(Expect.duplicatedTo) {...
 }
 

Parameters

Returns:

getDefault_timeout

Returns:

getProcess

Returns:

isNotransfer

Returns:

isRestart_timeout_upon_receive

Returns:

printDebugInfo

print internal debug information to stderr.

Returns:

send

Parameters

Returns:

setDefault_timeout

Parameters

Returns:

setNotransfer

Parameters

Returns:

setRestart_timeout_upon_receive

Parameters

Returns:

spawn

Creates an Expect object by spawning a command.
To Linux users, perhaps you need to use "bash -i" if you want to spawn Bash.
Note: error stream of the process is redirected to output stream.

Parameters

Returns: