How to Read Linux Command Output in Windows Using AutoHotKey and PuTTY for VNC Connection

When working with Windows and Linux systems, you often need to automate tasks that require interaction between the two environments. In this guide, we will walk you through the process of reading command output from a Linux server using AutoHotKey (AHK) and a command-line client like PuTTY. We'll focus on parsing the output to determine success and extracting credentials, and then using those credentials to connect to a VNC server on the Windows side.

Understanding Your Requirements

Your goal is to:

Run processes on a Debian server. Wait until the processes are finished. Read the output to check if the last word on a line is 'done', indicating success. Extract specific lines of credentials (logins and passwords). Pass these credentials to a VNC client on the Windows side.

Steps for StreamReader

1. Logging into the Linux Server

First, log into your Debian server using PuTTY. PuTTY is a popular SSH client for Windows. It allows you to connect to Linux servers and run commands.

2. Running Commands and Redirecting Output

To capture the command output, you can redirect it to a file:

command  output.txt

This command runs the specified command and saves the output to output.txt. You can then parse this file to extract the necessary information.

3. Parsing the Output Using AutoHotKey

Once you have the output in a file, you can use AutoHotKey to automate the process of reading and parsing the output. Here's a simple example:

FileRead, Output, output.txt  ; Read the contents of the file into the variable 'Output'StringSplit, Lines, Output, `n  ; Split the output into linesLinesTraversed  1Loop, Parse, Lines, `n  ; Loop through each line{    IfInString, A_LoopField, done  ; Check if the line contains the word 'done'        {            ; Process the success condition            MsgBox, Command executed successfully!            Output : myList[A_LoopField] ; Extract credentials            FileAppend, Output, credentials.txt  ; Save credentials to a file        }    LinesTraversed   1}; Read the credentials fileFileRead, Credentials, credentials.txtStringSplit, Credentials, Credentials, `n  ; Split credentials into an arrayPassword : Credentials[2]  ; Assuming the second line contains the passwordRun, vnc-client -login %Credentials[1] -password %Password  ; Launch the VNC client with credentials

4. Automating the Process

The above script can be modified to run automatically. Place the script in a reliable execution environment, such as a scheduled task or a script that runs on login.

Additional Tips and Commands

Using sed, awk, grep, and Pipes

For more complex parsing tasks, you can use command-line utilities like sed, awk, and grep on the Linux side. Here are some examples:

sed for modifying or manipulating text in files: sed -n -e '/done/p' output.txt - Extract lines containing 'done' awk for splitting and manipulating fields: awk '{print $NF}' output.txt - Extract the last column of each line grep for searching for specific patterns: grep -E 'login|password' output.txt - Search for lines containing 'login' or 'password'

Redirecting Output and Checking Exit Codes

For better control over the command execution and its results, use the exit code. You can check the exit code with:

if [ $? -eq 0 ]; then    echo "Command executed successfully"fi

This checks if the command executed successfully and executes the corresponding actions.

Conclusion

By following the steps outlined in this guide, you can automate the process of capturing and parsing command output from your Linux server, extracting necessary credentials, and using those credentials to connect to a VNC server on your Windows side. This approach not only enhances automation but also ensures security by keeping sensitive information off the command line.