Android™
Android™
Receive from an SSH Channel Until a Pattern Matches
See more SSH Examples
Demonstrates the Chilkat Ssh.ChannelReceiveUntilMatch method, which receives text until the accumulated text matches a pattern. The arguments are the channel number, the pattern, the charset, and whether matching is case-sensitive. Existing buffered text is checked before waiting for more network data.
Important: Set the ReadTimeoutMs property before calling this method. It defaults to 0, meaning no limit, so without it the call waits forever if the received data never contains a match.
Background: Driving a shell channel means knowing when the remote side has finished talking. With no PTY requested the shell is non-interactive and never prints a prompt, so the reliable signal is a marker you deliberately echo after your command. This method automates "read until you see X." The pattern syntax is deliberately minimal: literal characters plus
*, which matches zero or more characters and can span line breaks. ? and bracket classes are not supported, and backslash does not escape a literal *.Chilkat Android™ Downloads
// Important: Don't forget to include the call to System.loadLibrary
// as shown at the bottom of this code sample.
package com.test;
import android.app.Activity;
import com.chilkatsoft.*;
import android.widget.TextView;
import android.os.Bundle;
public class SimpleActivity extends Activity {
private static final String TAG = "Chilkat";
// Called when the activity is first created.
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
boolean success = false;
// Demonstrates the Ssh.ChannelReceiveUntilMatch method, which receives text until the
// accumulated text matches a pattern. The 1st argument is the channel number, the 2nd is the
// pattern, the 3rd is the charset, and the 4th selects case-sensitive matching. The pattern
// supports literal characters plus "*", which matches zero or more characters.
CkSsh ssh = new CkSsh();
int sshPort = 22;
success = ssh.Connect("ssh.example.com",sshPort);
if (success == false) {
Log.i(TAG, ssh.lastErrorText());
return;
}
// Normally you would not hard-code the password in source. You should instead obtain it
// from an interactive prompt, environment variable, or a secrets vault.
String password = "mySshPassword";
success = ssh.AuthenticatePw("mySshLogin",password);
if (success == false) {
Log.i(TAG, ssh.lastErrorText());
return;
}
int channelNum = ssh.OpenSessionChannel();
if (channelNum < 0) {
Log.i(TAG, ssh.lastErrorText());
return;
}
// Start a shell WITHOUT requesting a PTY. Without a PTY the shell sees it is connected to a
// raw data pipe and enters non-interactive mode: it suppresses the command prompt, does not
// echo typed commands back, and skips interactive login scripts. The output is therefore
// clean and easily parseable -- but because no prompt is ever sent, code must not wait for
// one. Instead, have each command print a predictable marker, or wait for EOF / channel close.
success = ssh.SendReqShell(channelNum);
if (success == false) {
Log.i(TAG, ssh.lastErrorText());
return;
}
// There is no prompt to wait for, so make the command itself announce when it has finished
// by echoing a marker after it.
success = ssh.ChannelSendString(channelNum,"ls -l /tmp; echo DONE_MARKER\n","utf-8");
if (success == false) {
Log.i(TAG, ssh.lastErrorText());
return;
}
// IMPORTANT: Set a read timeout before receiving until a match. ReadTimeoutMs defaults to 0,
// which means no limit -- without it, this call waits forever if the received data never
// contains a match.
ssh.put_ReadTimeoutMs(15000);
// Receive until the marker appears in the output.
boolean caseSensitive = false;
success = ssh.ChannelReceiveUntilMatch(channelNum,"DONE_MARKER","utf-8",caseSensitive);
if (success == false) {
Log.i(TAG, ssh.lastErrorText());
return;
}
String output = ssh.getReceivedText(channelNum,"utf-8");
if (ssh.get_LastMethodSuccess() == false) {
Log.i(TAG, ssh.lastErrorText());
return;
}
Log.i(TAG, output);
ssh.Disconnect();
}
static {
System.loadLibrary("chilkat");
// Note: If the incorrect library name is passed to System.loadLibrary,
// then you will see the following error message at application startup:
//"The application <your-application-name> has stopped unexpectedly. Please try again."
}
}