Ruby

SSH ReceiveUntilMatchN

Demonstrates how to call the SSH ChannelReceiveUntilMatchN method. Ruby

require 'chilkat'

success = false

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

ssh = Chilkat::CkSsh.new()

# For the sake of the example, pretend the remote shell prompt
# will be any of the following:
saPrompts = Chilkat::CkStringArray.new()

saPrompts.Append("~$")
saPrompts.Append("mars#")
saPrompts.Append("jupiter%")
saPrompts.Append("chilkat$")
saPrompts.Append("admin>")

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

success = ssh.Connect(hostname,port)
if (success != true)
    print ssh.lastErrorText() + "\n";
    exit
end

# Wait a max of 10 seconds when reading responses..
ssh.put_IdleTimeoutMs(10000)

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

# Open a session channel.  (It is possible to have multiple
# session channels open simultaneously.)
channelNum = ssh.OpenSessionChannel()
if (channelNum < 0)
    print ssh.lastErrorText() + "\n";
    exit
end

termType = "dumb"
widthInChars = 120
heightInChars = 40
# Use 0 for pixWidth and pixHeight when the dimensions
# are set in number-of-chars.
pixWidth = 0
pixHeight = 0
success = ssh.SendReqPty(channelNum,termType,widthInChars,heightInChars,pixWidth,pixHeight)
if (success != true)
    print ssh.lastErrorText() + "\n";
    exit
end

# Start a shell on the channel:
success = ssh.SendReqShell(channelNum)
if (success != true)
    print ssh.lastErrorText() + "\n";
    exit
end

#  Run the 1st command in the remote shell, which will be to
#  "cd" to a subdirectory.
success = ssh.ChannelSendString(channelNum,"cd workspace\n","utf-8")
if (success != true)
    print ssh.lastErrorText() + "\n";
    exit
end

# Retrieve the output to the next prompt:
caseSensitiveMatch = true
success = ssh.ChannelReceiveUntilMatchN(channelNum,saPrompts,"utf-8",caseSensitiveMatch)
if (success != true)
    print ssh.lastErrorText() + "\n";
    exit
end

#  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...
cmdOutput = ssh.getReceivedText(channelNum,"utf-8")
if (ssh.get_LastMethodSuccess() != true)
    print ssh.lastErrorText() + "\n";
    exit
end

print cmdOutput + "\n";

#  Run the 2nd command in the remote shell, which will be
#  to "ls" the directory.
success = ssh.ChannelSendString(channelNum,"ls\n","utf-8")
if (success != true)
    print ssh.lastErrorText() + "\n";
    exit
end

# Retrieve and display the output.
success = ssh.ChannelReceiveUntilMatchN(channelNum,saPrompts,"utf-8",caseSensitiveMatch)
if (success != true)
    print ssh.lastErrorText() + "\n";
    exit
end

cmdOutput = ssh.getReceivedText(channelNum,"utf-8")
if (ssh.get_LastMethodSuccess() != true)
    print ssh.lastErrorText() + "\n";
    exit
end

print cmdOutput + "\n";

#  Start the final command in the remote shell.  This example
#  will send a "ls -l" command to retrieve the long format directory listing.
success = ssh.ChannelSendString(channelNum,"ls -l\n","utf-8")
if (success != true)
    print ssh.lastErrorText() + "\n";
    exit
end

# 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.
success = ssh.ChannelSendEof(channelNum)
if (success != true)
    print ssh.lastErrorText() + "\n";
    exit
end

# 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.
pollTimeoutMs = 2000
n = ssh.ChannelReadAndPoll(channelNum,pollTimeoutMs)
if (n < 0)
    print ssh.lastErrorText() + "\n";
    exit
end

# Close the channel:
success = ssh.ChannelSendClose(channelNum)
if (success != true)
    print ssh.lastErrorText() + "\n";
    exit
end

# 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.
success = ssh.ChannelReceiveToClose(channelNum)
if (success != true)
    print ssh.lastErrorText() + "\n";
    exit
end

cmdOutput = ssh.getReceivedText(channelNum,"utf-8")
if (ssh.get_LastMethodSuccess() != true)
    print ssh.lastErrorText() + "\n";
    exit
end

print cmdOutput + "\n";

# Disconnect
ssh.Disconnect()