unix fun post

Author: csandrew-dev

content/posts/unix-fun.md

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+---
+title: "Unix Fun"
+date: 2025-01-30T10:28:03-05:00
+draft: false
+tags: ["unix", "linux", "CLI", "command line"]
+author: "me"
+showToc: true
+TocOpen: false
+hidemeta: false
+comments: false
+description: "Some fun tasks to practice unix commands and nice one-liners"
+canonicalURL: ""
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+    Text: "Suggest Changes"
+    appendFilePath: true
+---
+# Fun Linux/Unix Tasks and Commands
+
+Just a little context, this is a modified version of an assignment for my software security class so we are using the [Seed Labs VM](https://seedsecuritylabs.org/) so if you want to follow along, set that up on your machine. 
+
+# Task 1:
+
+## Item 1: Enable ssh
+
+ssh is already enabled on the base vm.
+
+### Command:
+
+`ssh seed@seedvm.local.lan`  
+
+This connects to the vm via ssh, command {use}@{host} and  
+
+`systemctl status sshd`
+
+This asks the OS “what is the status of the sshd service?”
+
+### Output:
+
+![](../../unix-fun/task1.1.png#center)
+
+![](../../unix-fun/task1.1(2).png#center)
+
+## Item 2: Enable SFTP
+
+sftp is already enabled on the base vm.
+
+### Command:
+
+`sftp seed@seedvm.local.lan`   
+
+this connects to the vm using sftp, so command {user}@{host} and
+
+`ps aux | grep sftp`  
+
+lists all running processes and filters the output to show only those related to sftp, helping check if an SFTP process is running
+
+### Output:
+
+![](../../unix-fun/task1.2.png#center)
+
+![](../../unix-fun/task1.1(2).png#center)
+
+# Task 2:
+
+## Item 1:download
+
+Couldn’t use wget or curl, so had to download through my class canvas page 😓.
+
+## Item 2: copy the tarballs into ~/Documents
+
+### Command:
+
+`stfp> put hw1.*.tar.gz /home/seed/Documents/`  
+
+Put is the command to move a file from local to remote and then the name of the local file, * to denote any hw1. file and then the location on the remote.
+
+### `Output:`
+
+![](../../unix-fun/task2.2.png#center)
+
+## Item 3: decompress the tarballs
+
+### Command:
+
+`for f in *.gz; do tar -xvf “$f”; done`
+
+Loop through files ending in .gz and run the command “tar -xvf {file}” until the loop finishes.
+
+### Output:
+
+![](../../unix-fun/task2.3.png#center)
+
+![](../../unix-fun/task2.3(2).png#center)
+
+# Task 3:
+
+## Item 1: List the contents of the "hw1.1" directory using the "ls" command
+
+### Command:
+
+`ls -latrh`  
+
+ls, list command, -l is long listing, -a is show all files(show hidden), -tr is sort by time and then reverse, finally -h is human readable for the size of files.
+
+### Output:
+
+![](../../unix-fun/task3.1.png#center)
+![](../../unix-fun/task3.1(2).png#center)
+
+## Item 2: Run the following command "cat /usr/share/dict/words | grep -i hello > /tmp/words.log"
+
+### Explanation:
+
+This command is using the cat command to display the contents of /usr/share/dict/words to stdout but the “|” redirects this output to the input for the grep command, the -i is to have grep ignore the casing of the letters in the file, “hello” is the string we are searching for with grep, the “>” means we are going to write this output to a file, in this case /tmp/words.log.
+
+### Output:
+
+![](../../unix-fun/task3.2.png#center)
+
+## Item 3: Copy the file numbers.txt from the current directory to the java subdirectory
+
+### Command:
+
+`cp numbers.txt ./java/`  
+
+Cp command is copy and then SOURCE DEST, in this case numbers.txt is in the current directory so just put the file name. Then DEST is ./java/ to show . is current directory and java/ shows it is a directory and then nothing after the last / means keep the file named numbers.txt
+
+### Output:
+
+![](../../unix-fun/task3.3.png#center)
+
+## Item 4: Rename the file Burrot.java to Borat.java
+
+### Command:
+
+`mv Burrot.java Borat.java`  
+
+mv command to “move” the file from Burrot.java to Borat.java, in this case renaming it.
+
+### Output:
+
+![](../../unix-fun/task3.4.png#center)
+
+## Item 5: Delete the files diff.html and diff.css
+
+### Command:
+
+`rm diff.*`  
+
+Remove files with the start of “diff.” and the * the is a wildcard to remove any file type matching “diff.”
+
+### Output:
+
+![](../../unix-fun/task3.5.png#center)
+
+## Item 6: List all web page files (files whose names end with the extension .html or .css) in the current directory.
+
+### Command:
+
+`ls -- *html *.css`  
+
+List the -- is a shorthand for name of file. Then *.html looks for any files html files and *.css looks for any css files.
+
+### Output:
+
+![](../../unix-fun/task3.6.png#center)
+
+## Item 7: Copy all the text files (files whose names end with .txt) from the current folder to the website subdirectory
+
+### Command:
+
+`cp *.txt ./website/`  
+
+Copy any files with the ending .txt to the . current directory website directory.
+
+### Output:
+
+![](../../unix-fun/task3.7.png#center)
+
+## Item 8: Display the contents of all files whose names begin with verse and end with the extension .txt
+
+### Command:
+
+`cat verse*.txt`  
+
+Cat to display the contents of files. Then verse is the start of the file and * to match anything after and then .txt to match the ending of the file.
+
+### Output:
+
+![](../../unix-fun/task3.8.png#center)
+
+# Task 4:
+
+## Item 1:
+
+### Command:
+
+`sort -u animals2.txt | head -n 16`  
+
+sort command, -u for uniqname removes duplicates, animals2.txt is the file put in an argument, piped to head -n 16 to show the first 16 items out the output.
+
+### Output:
+
+![](../../unix-fun/task4.1.png#center)
+
+## Item 2: Combine the contents of files verse1.txt, verse2.txt, and verse3.txt into a new file lyrics.txt
+
+### Command:
+
+`cat verse*.txt > lyrics.txt`  
+
+cat all files that match verse(wildcard).txt and write that to lyrics.txt
+
+### Output:
+
+![](../../unix-fun/task4.2.png#center)
+
+## Item 3: Display all lines from animals.txt that contain the word "growl" ignoring case, in reverse-ABC-sorted order and with no duplicates. Output the lines themselves only.
+
+### Command:
+
+`sort -ur animals.txt | grep -i growl`  
+
+sort -ur to sort animals by unique and in reverse order, pipe that output to grep -i to ignore case of target string “growl”
+
+### Output:
+
+![](../../unix-fun/task4.3.png#center)
+
+# Task 5:
+
+## Item 1: Set the file example1.txt in the current directory so that its group and other can write to the file.
+
+### Command:
+
+`chmod go+w example1.txt`  
+
+Change modification of g (group) and o (other) + adds w (write) permission to the example1.txt
+
+### Output:
+
+![](../../unix-fun/task5.1.png#center)
+
+## Item 2: Set all files with extensions .dat and .doc to be read/writable (but not executable) by their owner, and to have no access from others.
+
+### Command:
+
+If you know the current permissions:
+
+`chmod go-r *.dat *.doc`
+
+Chmod g(roup) o(other) - (remove) r(ead permissions)
+
+If you don’t know the current permissions:
+
+`chmod u=rw,go= *.dat *.doc`  
+
+Chmod u(ser) set to r(ead)w(rite), g(roup)o(other) set to nothing on all dat and doc files.
+
+### Output:
+
+![](../../unix-fun/task5.2.png#center)
+![](../../unix-fun/task5.2(2).png#center)
+
+## Item 3: How many users exist on this Linux system that use the Bash shell by default?
+
+### Command:
+
+`grep “/bin/bash” /etc/passwd | wc -l`  
+
+grep for string “/bin/bash” in the passwd file, pipe that output to wc (word count) and -l is for newline count.
+
+### Output:
+
+![](../../unix-fun/task5.3.png#center)
+
+## Item 4: Create a file foo.txt using the “touch” command. Change the file's last-modified date to be January 4 of this year at 8:56am
+
+### Command:
+
+`touch -t 01040856 foo.txt`  
+
+touch -t to set time modified and then 01 is for January, 04 is for the 4th of January, 08 is for 8am, and 56 is for 8:56am, foo.txt is the name of the file.
+
+### Output:
+
+![](../../unix-fun/task5.4.png#center)
+
+# Conclusion:
+
+I very much enjoyed this assignment. I took an Intro to Linux class at my local community college while I was in high school and this took me right back there. I think having the ability to work quickly in the command line is a great skill to have. My recommendation is that people take a look at these two websites/talks/courses if they are interested in the same topics:
+
+* [https://missing.csail.mit.edu/](https://missing.csail.mit.edu/)   
+* [awk sed grep slides](https://bpb-us-e1.wpmucdn.com/sites.psu.edu/dist/4/24696/files/2024/07/psumac2024-Awk-sed-grep-Together-we-can-change-anything-compressed.pdf) and [awk sed grep talk video](https://youtu.be/axmDzoUov_8)
+
+As you may be able to tell I’m very interested in the “poweruser” type of things so this was a nice exercise. I think so far these topics and skills is something that all computer science students should have within in their first or second year.