(C) Using sudo in an SSH Shell Session

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

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#include <C_CkSsh.h>
#include <C_CkStringBuilder.h>

void ChilkatSample(void)
    {
    HCkSsh ssh;
    int port;
    BOOL success;
    int channelNum;
    HCkStringBuilder sbCommands;

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

    ssh = CkSsh_Create();

    port = 22;
    success = CkSsh_Connect(ssh,"the-ssh-server.com",port);
    if (success != TRUE) {
        printf("%s\n",CkSsh_lastErrorText(ssh));
        CkSsh_Dispose(ssh);
        return;
    }

    // Authenticate using login/password:
    success = CkSsh_AuthenticatePw(ssh,"theSshLogin","theSshPassword");
    if (success != TRUE) {
        printf("%s\n",CkSsh_lastErrorText(ssh));
        CkSsh_Dispose(ssh);
        return;
    }

    // Start a shell session.
    // (The QuickShell method was added in Chilkat v9.5.0.65)
    channelNum = CkSsh_QuickShell(ssh);
    if (channelNum < 0) {
        printf("%s\n",CkSsh_lastErrorText(ssh));
        CkSsh_Dispose(ssh);
        return;
    }

    // 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 = CkStringBuilder_Create();
    CkStringBuilder_Append(sbCommands,"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.
    CkStringBuilder_Append(sbCommands,"echo THIS 'IS' THE END OF THE SCRIPT\n");

    // Send the commands..
    success = CkSsh_ChannelSendString(ssh,channelNum,CkStringBuilder_getAsString(sbCommands),"ansi");
    if (success != TRUE) {
        printf("%s\n",CkSsh_lastErrorText(ssh));
        CkSsh_Dispose(ssh);
        CkStringBuilder_Dispose(sbCommands);
        return;
    }

    // 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 = CkSsh_ChannelSendEof(ssh,channelNum);

    // Receive output up to our marker.
    success = CkSsh_ChannelReceiveUntilMatch(ssh,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 = CkSsh_ChannelSendClose(ssh,channelNum);

    // Get any remaining output..
    success = CkSsh_ChannelReceiveToClose(ssh,channelNum);

    // Get the complete output for all the commands in the session.
    printf("--- output ----\n");
    printf("%s\n",CkSsh_getReceivedText(ssh,channelNum,"ansi"));


    CkSsh_Dispose(ssh);
    CkStringBuilder_Dispose(sbCommands);

    }