Visual FoxPro

Check Whether an SSH Exit Status Was Received

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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LOCAL lnSuccess
LOCAL loSsh
LOCAL lnSshPort
LOCAL lcPassword
LOCAL lnChannelNum
LOCAL lnExitStatus

lnSuccess = 0

*  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 1, call GetChannelExitStatus to read the value.

loSsh = CreateObject('Chilkat.Ssh')

lnSshPort = 22
lnSuccess = loSsh.Connect("ssh.example.com",lnSshPort)
IF (lnSuccess = 0) THEN
    ? loSsh.LastErrorText
    RELEASE loSsh
    CANCEL
ENDIF

*  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.
lcPassword = "mySshPassword"

lnSuccess = loSsh.AuthenticatePw("mySshLogin",lcPassword)
IF (lnSuccess = 0) THEN
    ? loSsh.LastErrorText
    RELEASE loSsh
    CANCEL
ENDIF

lnChannelNum = loSsh.OpenSessionChannel()
IF (lnChannelNum < 0) THEN
    ? loSsh.LastErrorText
    RELEASE loSsh
    CANCEL
ENDIF

lnSuccess = loSsh.SendReqExec(lnChannelNum,"test -f /etc/hosts")
IF (lnSuccess = 0) THEN
    ? loSsh.LastErrorText
    RELEASE loSsh
    CANCEL
ENDIF

*  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.
loSsh.ReadTimeoutMs = 15000

lnSuccess = loSsh.ChannelReceiveToClose(lnChannelNum)
IF (lnSuccess = 0) THEN
    ? loSsh.LastErrorText
    RELEASE loSsh
    CANCEL
ENDIF

*  The server is not required to send an exit status for every channel type or command.
IF (loSsh.ChannelReceivedExitStatus(lnChannelNum)) THEN
    lnExitStatus = loSsh.GetChannelExitStatus(lnChannelNum)
    ? "Exit status: " + STR(lnExitStatus)
ELSE
    ? "The server did not provide an exit status."
ENDIF

loSsh.Disconnect()

RELEASE loSsh