Tcl

Connect to an SFTP Server

Demonstrates the Chilkat SFtp.Connect method, which establishes the SSH connection to an SFTP server. The first argument is the hostname (a DNS name or numeric IPv4/IPv6 address) and the second is the TCP port, usually 22. Connecting is the first of three setup steps.

Background: SFTP runs as a subsystem over SSH, so a session is set up in three fixed steps: Connect establishes the encrypted SSH transport, an Authenticate method logs in, and InitializeSftp opens the SFTP subsystem. File and directory operations are only possible after all three succeed.

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Tcl


load ./chilkat.dll

set success 0

#  Demonstrates the SFtp.Connect method, which establishes the SSH connection to an SFTP server.
#  The 1st argument is the hostname (a DNS name or numeric IP) and the 2nd is the TCP port.
#  
#  Connecting is only the first of three steps.  The full sequence is:
#    1. Connect
#    2. AuthenticatePw (or another authentication method)
#    3. InitializeSftp

set sftp [new_CkSFtp]

#  Step 1: Connect the SSH transport.  Port 22 is the usual port.
set port 22
set success [CkSFtp_Connect $sftp "sftp.example.com" $port]
if {$success == 0} then {
    puts [CkSFtp_lastErrorText $sftp]
    delete_CkSFtp $sftp
    exit
}

#  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.
set password "mySshPassword"

set success [CkSFtp_AuthenticatePw $sftp "mySshLogin" $password]
if {$success == 0} then {
    puts [CkSFtp_lastErrorText $sftp]
    delete_CkSFtp $sftp
    exit
}

#  Step 3: Open the SFTP subsystem.  This must be done after authentication and before any
#  file or directory operations.
set success [CkSFtp_InitializeSftp $sftp]
if {$success == 0} then {
    puts [CkSFtp_lastErrorText $sftp]
    delete_CkSFtp $sftp
    exit
}

puts "Connected, authenticated, and SFTP subsystem initialized."

CkSFtp_Disconnect $sftp

delete_CkSFtp $sftp