(Lianja) Using sudo in an SSH Shell Session

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Demonstrates how to run a command as sudo in a shell session.

Chilkat Lianja Extension Download Chilkat Lianja Extension

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

loSsh = createobject("CkSsh")

lnPort = 22
llSuccess = loSsh.Connect("the-ssh-server.com",lnPort)
if (llSuccess <> .T.) then
    ? loSsh.LastErrorText
    release loSsh
    return
endif

// Authenticate using login/password:
llSuccess = loSsh.AuthenticatePw("theSshLogin","theSshPassword")
if (llSuccess <> .T.) then
    ? loSsh.LastErrorText
    release loSsh
    return
endif

// Start a shell session.
// (The QuickShell method was added in Chilkat v9.5.0.65)
lnChannelNum = loSsh.QuickShell()
if (lnChannelNum < 0) then
    ? loSsh.LastErrorText
    release loSsh
    return
endif

// Construct a StringBuilder with our command ("ls") run with "sudo"
// Note: The line-endings are potentially important.  Some SSH servers may
// require either LF or CRLF line endings.  (Unix/Linux/OSX servers typically
// use bare-LF line endings.  Windows servers likely use CRLF line endings.)

// Using "sudo -S" causes the sudo prompt to be written to stderr,
// and the password is read from stdin (i.e. from the echo command ouput).
// The sudo commands -p option allows us to set the prompt, and we can set it to
// the empty string, thus eliminating the prompt from the stderr completely.
// This allows us to run the command as root (super-user) with no prompt.
loSbCommands = createobject("CkStringBuilder")
loSbCommands.Append('echo "theSshPassword" | sudo -S -p "" ls' + Chr(10))

// Add another command to echo a marker string that
// we'll use in ChannelReceiveUntilMatch below.
// The use of single quotes around 'IS' is a trick so that the output
// of the command is "THIS IS THE END OF THE SCRIPT", but the terminal echo
// includes the single quotes.  This allows us to read until we see the actual
// output of the last command.
loSbCommands.Append("echo THIS 'IS' THE END OF THE SCRIPT" + Chr(10))

// Send the commands..
llSuccess = loSsh.ChannelSendString(lnChannelNum,loSbCommands.GetAsString(),"ansi")
if (llSuccess <> .T.) then
    ? loSsh.LastErrorText
    release loSsh
    release loSbCommands
    return
endif

// Send an EOF to indicate no more commands will be sent.
// For brevity, we're not checking the return values of each method call.
// Your code should check the success/failure of each call.
llSuccess = loSsh.ChannelSendEof(lnChannelNum)

// Receive output up to our marker.
llSuccess = loSsh.ChannelReceiveUntilMatch(lnChannelNum,"THIS IS THE END OF THE SCRIPT","ansi",.T.)

// Close the channel.
// It is important to close the channel only after receiving the desired output.
llSuccess = loSsh.ChannelSendClose(lnChannelNum)

// Get any remaining output..
llSuccess = loSsh.ChannelReceiveToClose(lnChannelNum)

// Get the complete output for all the commands in the session.
? "--- output ----"
? loSsh.GetReceivedText(lnChannelNum,"ansi")


release loSsh
release loSbCommands