152 lines
4.9 KiB
Markdown
152 lines
4.9 KiB
Markdown
# Lab 1
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## Tasks
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- [x] 1. **Connect**
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```
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I ran the commands from VirtualBox
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```
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- [x] 2. **Explore**
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```
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I ran the sample commands
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```
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- [x] 3. **Play**
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- [x] grep
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```sh
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vboxuser@ubel:~/lab-1$ vim extra/folders/example.txt
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vboxuser@ubel:~/lab-1$ grep -i "Error" syslog
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this is an error i am an error!
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yeah I am another error!
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vboxuser@ubel:~/lab-1$ grep -ir "Error" syslog
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this is an error i am an error!
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yeah I am another error!
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vboxuser@ubel:~/lab-1$ ls
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extra syslog
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vboxuser@ubel:~/lab-1$ ls
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extra syslog
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vboxuser@ubel:~/lab-1$ grep -r "error" syslog
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this is an error i am an error!
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yeah I am another error!
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vboxuser@ubel:~/lab-1$ ls
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extra syslog
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vboxuser@ubel:~/lab-1$ cat extra/folders/example.txt
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error I am a file
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hello world
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i am not an
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but this is an error!
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vboxuser@ubel:~/lab-1$ grep -r "error" .
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./extra/folders/example.txt:error I am a file
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./extra/folders/example.txt:but this is an error!
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./syslog:this is an error i am an error!
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./syslog:yeah I am another error!
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vboxuser@ubel:~/lab-1$ grep -rc "error" .
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./extra/folders/example.txt:2
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./syslog:2
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vboxuser@ubel:~/lab-1$ grep -ra "error" .
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./extra/folders/example.txt:error I am a file
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./extra/folders/example.txt:but this is an error!
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./syslog:this is an error i am an error!
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./syslog:yeah I am another error!
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vboxuser@ubel:~/lab-1$ grep -rb "error" .
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./extra/folders/example.txt:0:error I am a file
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./extra/folders/example.txt:48:but this is an error!
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./syslog:0:this is an error i am an error!
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./syslog:47:yeah I am another error!
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```
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- [x] tail
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Displays the end of the file -- if you add -f (for follow),
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you can display the contents indefinitely. It is fun to snoop
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on bots who are trying to log into my server, and this command is useful
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for that.
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```sh
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sudo tail -f /var/log/auth.log
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```
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- [x] man
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Better than Google when you have no internet connection
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or access to chatGPT. Holds an exhaustive (I assume) list of
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available commands.
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```sh
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man grep
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man man
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```
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- [x] history
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Shows command history. I would usually use zsh and, if I needed to run a
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command, I would just press the "up" arrow. That is very tedious if
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I need to run something that I did > 5 commands ago. This is very useful
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if I needed to run an obscure command. Or maybe to just figure out what I did.
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```sh
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history
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history | grep "tail"
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man history
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```
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- [x] df
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Never used this command before. I randomly decided to check this on both MacOS
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(my computer is always running out of space for some reason or other)
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as well as on one of my linux boxes.
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There are a lot of differences. Feels like more similarities than differences,
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but a lot of the important columns are the same. It's also a good command
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for keeping an eye on the mounted volumes on my linux box.
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Also, since the two commands are so different, I don't think I'll ever be able
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to remember them!
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Stands for "disk free".
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```sh (on Mac)
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df (display free disk space)
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df -h
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```
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```sh (on VM Ubuntu)
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df (report file system space usage)
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df -h
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```
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- [x] du
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Displays file usage. Should use this to investigate where all the space
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on my local Mac is going.
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```sh
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man du
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du -hS
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du -s * | sort -nr > $HOME/user_space_report.txt
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```
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- [x] ps
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Showed me a list of running processes. By default it only shows you
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the processes that were started/were run personally by you on a terminal.
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Also: the man for `ps` under the Ubuntu box mentioned you can use
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UNIX (?), BSD (default for mac os?), and GNU (what I assume are the usual default commands) options for ps, provided you use the flags in a specific way.
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Once in a blue moon I have to use pkill some orphaned program, and without fail
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I have to google how to every time. Maybe I can just use the pids from here instead?
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```sh (on Mac)
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man ps
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ps -A
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```
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```sh (on Linux)
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man ps
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```
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- [x] top
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Looks similar to ps, but you get a whole dashboard. I could
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see how you could use this to monitor programs. This is the
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text version of what I'd use the activity monitor for.
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```sh
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top
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```
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- [x] htop
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Top, but **fancier**! It's keyboard navigable AND mouse navigable,
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and comes with a bunch of colors out of the box. Very cool!
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```sh
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htop
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```
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- [x] exit
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Exits you out of the current terminal session.
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extra reading
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- [x] [The Linux Command Line](http://linuxcommand.org/tlcl.php)
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WIP still reading this
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- [x] [Grep mini-zine](https://wizardzines.com/comics/grep/)
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- [x] [reddit thread: bsd v gnu](https://old.reddit.com/r/linuxquestions/comments/vzmfye/differences_between_bsd_and_gnu_utilities/)
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* Most of this goes completely over my head. But this was interesting to look at.
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