(Ruby) Using sudo in an SSH Shell Session

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

Chilkat Ruby Downloads install from rubygems.org gem install chilkat or download... Ruby Library for Windows, MacOS, Linux, Alpine Linux

require 'chilkat'

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

ssh = Chilkat::CkSsh.new()

port = 22
success = ssh.Connect("the-ssh-server.com",port)
if (success != true)
    print ssh.lastErrorText() + "\n";
    exit
end

# Authenticate using login/password:
success = ssh.AuthenticatePw("theSshLogin","theSshPassword")
if (success != true)
    print ssh.lastErrorText() + "\n";
    exit
end

# Start a shell session.
# (The QuickShell method was added in Chilkat v9.5.0.65)
channelNum = ssh.QuickShell()
if (channelNum < 0)
    print ssh.lastErrorText() + "\n";
    exit
end

# 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.
sbCommands = Chilkat::CkStringBuilder.new()
sbCommands.Append("echo \"theSshPassword\" | sudo -S -p \"\" ls\n")

# 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.
sbCommands.Append("echo THIS 'IS' THE END OF THE SCRIPT\n")

# Send the commands..
success = ssh.ChannelSendString(channelNum,sbCommands.getAsString(),"ansi")
if (success != true)
    print ssh.lastErrorText() + "\n";
    exit
end

# 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.
success = ssh.ChannelSendEof(channelNum)

# Receive output up to our marker.
success = ssh.ChannelReceiveUntilMatch(channelNum,"THIS IS THE END OF THE SCRIPT","ansi",true)

# Close the channel.
# It is important to close the channel only after receiving the desired output.
success = ssh.ChannelSendClose(channelNum)

# Get any remaining output..
success = ssh.ChannelReceiveToClose(channelNum)

# Get the complete output for all the commands in the session.
print "--- output ----" + "\n";
print ssh.getReceivedText(channelNum,"ansi") + "\n";