Combine your skills to accomplish a real-world challenge. Help your system administrator track down a hacker!
- [Instructor] Let's take a look…at how I solved this challenge.…The file that we were provided was an archive.…So the first step that I took was to write…tar xf log.tar.gz…and that created a file called auth.log.…As I'm sure you found out,…that file is thousands of lines long.…So I wanted to get a sense of what I was looking for.…Next I wrote less auth.log…just to take a look at all of the text.…
And scrolling around,…I started seeing invalid user login attempts.…Here, someone's trying to login as postgres,…and squid,…and office,…and many other names.…Each of these lines has the string input_userauth_request.…So I know I can look for that.…And on these lines,…the username occurs at a specific position.…
I can count from the left.…One, separator,…two, separator,…three, separator,…four,…five,…six,…seven, eight,…nine.…On each of these lines…that say input underscore userauth underscore request,…it's the ninth item.…So I'll clear the screen.…And let's start writing out the command…that I used to solve the problem.…
Now that I'm done looking at the text,…
- Recognize what the characters “-h” represent in the statement “df –h/home/alice/Documents”.
- Explain how to recall a previous command in Bash.
- Identify what the command “ls -l” will show.
- Recall what is needed to use the find command to look for files by name, size, and so on.
- List the two modes file permissions can be set to.
- Recall why many command line tools are intended to be used in pipes with other commands.
- Explain what the command “grep -E "" report.txt” will show.
- Identify what the “>” symbol is often used for.
Skill Level Beginner
Learning SQL Server Development on Linuxwith Joey D'Antoni1h 54m Intermediate
What you should know1m 51s
1. Setting Up Your Environment
2. Command-Line Basics
3. Files, Folders, and Permissions
4. Common Command-Line Tasks and Tools
5. A Peek at Some More Advanced Topics
Next steps1m 28s
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