Dart
Dart
Check Whether an SSH Exit Status Was Received
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Demonstrates the Chilkat Ssh.ChannelReceivedExitStatus method, which reports whether the server supplied an exit-status value for a channel. The only argument is the channel number. When it returns true, call GetChannelExitStatus to read the value.
Background: Always test this before reading the exit status, because the server is not required to send one for every channel type or command — treating a missing status as "0" would silently turn a failure into a success. Exit status is independent of EOF and CLOSE: it can arrive after EOF and either before or together with CLOSE.
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import 'package:chilkat/chilkat.dart';
void main() {
// Demonstrates the Ssh.ChannelReceivedExitStatus method, which reports whether the server
// supplied an exit-status value for a channel. The only argument is the channel number. When
// it returns true, call GetChannelExitStatus to read the value.
final ssh = CkSsh();
final sshPort = 22;
try {
ssh.connect('ssh.example.com', sshPort);
} on ChilkatException catch (e) {
print(e.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.
final password = 'mySshPassword';
try {
ssh.authenticatePw('mySshLogin', password);
} on ChilkatException catch (e) {
print(e.lastErrorText);
return;
}
final channelNum = ssh.openSessionChannel();
if (channelNum < 0) {
print(ssh.lastErrorText);
return;
}
try {
ssh.sendReqExec(channelNum, 'test -f /etc/hosts');
} on ChilkatException catch (e) {
print(e.lastErrorText);
return;
}
// IMPORTANT: Set a read timeout. ReadTimeoutMs defaults to 0, which means no limit -- without
// it, this call waits forever if the server never sends channel close.
ssh.readTimeoutMs = 15000;
try {
ssh.channelReceiveToClose(channelNum);
} on ChilkatException catch (e) {
print(e.lastErrorText);
return;
}
// The server is not required to send an exit status for every channel type or command.
if (ssh.channelReceivedExitStatus(channelNum)) {
final exitStatus = ssh.getChannelExitStatus(channelNum);
print('Exit status: $exitStatus');
} else {
print('The server did not provide an exit status.');
}
ssh.disconnect();
}