(Tcl) SSH Remote Shell Multiple Commands

Demonstrates how to start a shell on a remote SSH server, run a command, and retrieve the output, then run the next command, retrieve the output, etc.

Chilkat Tcl Extension Downloads Chilkat Tcl Extension Downloads

load ./chilkat.dll

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

set ssh [new_CkSsh]

# This is the prompt we'll be expecting to find in
# the output of the remote shell.

set myPrompt "chilkat@ubuntu:~/workspace$"

# Connect to an SSH server:

# Hostname may be an IP address or hostname:
set hostname "www.some-ssh-server.com"
set port 22

set success [CkSsh_Connect $ssh $hostname $port]
if {$success != 1} then {
    puts [CkSsh_lastErrorText $ssh]
    delete_CkSsh $ssh
    exit
}

# Wait a max of 10 seconds when reading responses..
CkSsh_put_IdleTimeoutMs $ssh 10000

# Authenticate using login/password:
set success [CkSsh_AuthenticatePw $ssh "myLogin" "myPassword"]
if {$success != 1} then {
    puts [CkSsh_lastErrorText $ssh]
    delete_CkSsh $ssh
    exit
}

# Open a session channel.  (It is possible to have multiple
# session channels open simultaneously.)

set channelNum [CkSsh_OpenSessionChannel $ssh]
if {$channelNum < 0} then {
    puts [CkSsh_lastErrorText $ssh]
    delete_CkSsh $ssh
    exit
}

set termType "dumb"
set widthInChars 120
set heightInChars 40
# Use 0 for pixWidth and pixHeight when the dimensions
# are set in number-of-chars.
set pixWidth 0
set pixHeight 0
set success [CkSsh_SendReqPty $ssh $channelNum $termType $widthInChars $heightInChars $pixWidth $pixHeight]
if {$success != 1} then {
    puts [CkSsh_lastErrorText $ssh]
    delete_CkSsh $ssh
    exit
}

# Start a shell on the channel:
set success [CkSsh_SendReqShell $ssh $channelNum]
if {$success != 1} then {
    puts [CkSsh_lastErrorText $ssh]
    delete_CkSsh $ssh
    exit
}

#  Run the 1st command in the remote shell, which will be to
#  "cd" to a subdirectory.
set success [CkSsh_ChannelSendString $ssh $channelNum "cd workspace\r\n" "ansi"]
if {$success != 1} then {
    puts [CkSsh_lastErrorText $ssh]
    delete_CkSsh $ssh
    exit
}

# Retrieve the output.
set success [CkSsh_ChannelReceiveUntilMatch $ssh $channelNum $myPrompt "ansi" 1]
if {$success != 1} then {
    puts [CkSsh_lastErrorText $ssh]
    delete_CkSsh $ssh
    exit
}

#  Display what we've received so far.  This clears
#  the internal receive buffer, which is important.
#  After we send the command, we'll be reading until
#  the next command prompt.  If the command prompt
#  is already in the internal receive buffer, it'll think it's
#  already finished...
set cmdOutput [CkSsh_getReceivedText $ssh $channelNum "ansi"]
if {[CkSsh_get_LastMethodSuccess $ssh] != 1} then {
    puts [CkSsh_lastErrorText $ssh]
    delete_CkSsh $ssh
    exit
}

puts "$cmdOutput"

#  Run the 2nd command in the remote shell, which will be
#  to "ls" the directory.
set success [CkSsh_ChannelSendString $ssh $channelNum "ls\r\n" "ansi"]
if {$success != 1} then {
    puts [CkSsh_lastErrorText $ssh]
    delete_CkSsh $ssh
    exit
}

# Retrieve and display the output.
set success [CkSsh_ChannelReceiveUntilMatch $ssh $channelNum $myPrompt "ansi" 1]
if {$success != 1} then {
    puts [CkSsh_lastErrorText $ssh]
    delete_CkSsh $ssh
    exit
}

set cmdOutput [CkSsh_getReceivedText $ssh $channelNum "ansi"]
if {[CkSsh_get_LastMethodSuccess $ssh] != 1} then {
    puts [CkSsh_lastErrorText $ssh]
    delete_CkSsh $ssh
    exit
}

puts "$cmdOutput"

#  Start the final command in the remote shell.  This example
#  will send a "ls -l" command to retrieve the long format directory listing.
set success [CkSsh_ChannelSendString $ssh $channelNum "ls -l\r\n" "ansi"]
if {$success != 1} then {
    puts [CkSsh_lastErrorText $ssh]
    delete_CkSsh $ssh
    exit
}

# Send an EOF.  This tells the server that no more data will 
# be sent on this channel.  The channel remains open, and
# the SSH client may still receive output on this channel.
set success [CkSsh_ChannelSendEof $ssh $channelNum]
if {$success != 1} then {
    puts [CkSsh_lastErrorText $ssh]
    delete_CkSsh $ssh
    exit
}

# Read whatever output may already be available on the
# SSH connection.  ChannelReadAndPoll returns the number of bytes
# that are available in the channel's internal buffer that
# are ready to be "picked up" by calling GetReceivedText
# or GetReceivedData.
# A return value of -1 indicates failure.
# A return value of -2 indicates a failure via timeout.

# The ChannelReadAndPoll method waits
# for data to arrive on the connection usingi the IdleTimeoutMs
# property setting.  Once the first data arrives, it continues
# reading but instead uses the pollTimeoutMs passed in the 2nd argument:
# A return value of -2 indicates a timeout where no data is received.

set pollTimeoutMs 2000
set n [CkSsh_ChannelReadAndPoll $ssh $channelNum $pollTimeoutMs]
if {$n < 0} then {
    puts [CkSsh_lastErrorText $ssh]
    delete_CkSsh $ssh
    exit
}

# Close the channel:
set success [CkSsh_ChannelSendClose $ssh $channelNum]
if {$success != 1} then {
    puts [CkSsh_lastErrorText $ssh]
    delete_CkSsh $ssh
    exit
}

# Perhaps we did not receive all of the commands output.
# To make sure,  call ChannelReceiveToClose to accumulate any remaining
# output until the server's corresponding "channel close" is received.
set success [CkSsh_ChannelReceiveToClose $ssh $channelNum]
if {$success != 1} then {
    puts [CkSsh_lastErrorText $ssh]
    delete_CkSsh $ssh
    exit
}

set cmdOutput [CkSsh_getReceivedText $ssh $channelNum "ansi"]
if {[CkSsh_get_LastMethodSuccess $ssh] != 1} then {
    puts [CkSsh_lastErrorText $ssh]
    delete_CkSsh $ssh
    exit
}

puts "$cmdOutput"

# Disconnect
CkSsh_Disconnect $ssh

delete_CkSsh $ssh