DataFlex
DataFlex
SSH Remote Shell
See more SSH Examples
Demonstrates starting a shell on a remote SSH server, running a command, and retrieving the output. The example sends the command, signals EOF so the server knows no more input is coming, and then receives the remaining output until the channel closes.
Background: A shell channel differs from an
exec channel in that it stays open for a stream of commands rather than running just one. No PTY is requested here, which is the recommended approach for automation: the shell detects a raw pipe and runs non-interactively, so no prompt is printed and typed commands are not echoed. Sending EOF is the SSH equivalent of Ctrl+D — it closes only the client-to-server direction, so output can still be received afterward, and it prompts the server to finish up and close the channel.Chilkat DataFlex Downloads
Use ChilkatAx-win32.pkg
Procedure Test
Boolean iSuccess
Handle hoSsh
String sHostname
Integer iPort
String sPassword
Integer iChannelNum
String sCmdOutput
String sTemp1
Boolean bTemp1
Move False To iSuccess
// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.
// Demonstrates starting a shell on a remote SSH server, running a command, and retrieving the
// output. No PTY is requested, which is the recommended approach for automation.
Get Create (RefClass(cComChilkatSsh)) To hoSsh
If (Not(IsComObjectCreated(hoSsh))) Begin
Send CreateComObject of hoSsh
End
Move "ssh.example.com" To sHostname
Move 22 To iPort
Get ComConnect Of hoSsh sHostname iPort To iSuccess
If (iSuccess = False) Begin
Get ComLastErrorText Of hoSsh To sTemp1
Showln sTemp1
Procedure_Return
End
// 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.
Move "mySshPassword" To sPassword
Get ComAuthenticatePw Of hoSsh "mySshLogin" sPassword To iSuccess
If (iSuccess = False) Begin
Get ComLastErrorText Of hoSsh To sTemp1
Showln sTemp1
Procedure_Return
End
Get ComOpenSessionChannel Of hoSsh To iChannelNum
If (iChannelNum < 0) Begin
Get ComLastErrorText Of hoSsh To sTemp1
Showln sTemp1
Procedure_Return
End
// 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.
Get ComSendReqShell Of hoSsh iChannelNum To iSuccess
If (iSuccess = False) Begin
Get ComLastErrorText Of hoSsh To sTemp1
Showln sTemp1
Procedure_Return
End
// Send the command. The trailing newline is required -- the shell acts on a line at a time.
Get ComChannelSendString Of hoSsh iChannelNum "ls -l /tmp" + (character(10)) "utf-8" To iSuccess
If (iSuccess = False) Begin
Get ComLastErrorText Of hoSsh To sTemp1
Showln sTemp1
Procedure_Return
End
// Send EOF to tell the server no more input is coming. The channel stays open and output can
// still be received.
Get ComChannelSendEof Of hoSsh iChannelNum To iSuccess
If (iSuccess = False) Begin
Get ComLastErrorText Of hoSsh To sTemp1
Showln sTemp1
Procedure_Return
End
// 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.
Set ComReadTimeoutMs Of hoSsh To 15000
// Receive the remaining output until the server closes the channel.
Get ComChannelReceiveToClose Of hoSsh iChannelNum To iSuccess
If (iSuccess = False) Begin
Get ComLastErrorText Of hoSsh To sTemp1
Showln sTemp1
Procedure_Return
End
Get ComGetReceivedText Of hoSsh iChannelNum "utf-8" To sCmdOutput
Get ComLastMethodSuccess Of hoSsh To bTemp1
If (bTemp1 = False) Begin
Get ComLastErrorText Of hoSsh To sTemp1
Showln sTemp1
Procedure_Return
End
Showln sCmdOutput
Send ComDisconnect To hoSsh
End_Procedure