updates

02-folder-structure/notes.md

@@ -0,0 +1,5 @@
+adduser 'name' -> for adding a new user  
+ex:-  
+<img width="258" height="28" alt="Screenshot 2026-04-17 150149" src="https://github.com/user-attachments/assets/7a65a4c2-8ac1-4802-b251-864d60d789f9" />  
+here chirantana is the user, but we can create multiple users inside the home
+

04-file-management/README.md

@@ -17,8 +17,8 @@
 12. **`tac file.txt`** – Displays file content in reverse order.
 13. **`less file.txt`** – Opens a file for viewing with scrolling support.
 14. **`more file.txt`** – Similar to `less`, but only moves forward.
-15. **`head -n 10 file.txt`** – Displays the first 10 lines of a file.
-16. **`tail -n 10 file.txt`** – Displays the last 10 lines of a file.
+15. **`head -n(10) file.txt`** – Displays the first 10 lines of a file. [n as 10 here]
+16. **`tail -n(10) file.txt`** – Displays the last 10 lines of a file. [n as 10 here]
 17. **`nano file.txt`** – Opens a simple text editor.
 18. **`vi file.txt`** – Opens a powerful text editor.
 19. **`echo 'Hello' > file.txt`** – Writes text to a file, overwriting existing content.

05-vi-shortcuts/README.md

@@ -64,7 +64,7 @@
 ### Working with Multiple Files
 - `:e filename` – Open a **new file**  
 - `:w` – Save file  
-- `:wq` – Save and exit  
+- `:wq!` – Save and exit  
 - `:q!` – Quit **without saving**  
 - `:split filename` – Split screen **horizontally** and open another file  
 - `:vsplit filename` – Split screen **vertically**  

07-process-management/README.md

@@ -16,10 +16,10 @@ A process is an instance of a running program. Linux provides multiple utilities
 - `kill PID` – Terminate a process by PID
 - `pkill processname` – Terminate a process by name
 - `kill -9 PID` – Force kill a process
-- `pkill -9 processname` – Kill all instances of a process
-- `kill -STOP PID` – Stop a running process
+- `pkill -9 processname` – Kills all (instances of a) process with the name 'processname'  
+- `kill -STOP PID` – Stop a running process     
 - `kill -CONT PID` – Resume a stopped process
-- `renice -n 10 -p PID` – Lower priority of a process
+- `renice -n 10 -p PID` – Lower priority of a process   [lesser the number, more the priority, ex:- 3>4>5, 2>10]  
 - `renice -n -5 -p PID` – Increase priority of a process (requires root)
 
 ### Background & Foreground Processes

07-process-management/notes.md

@@ -0,0 +1,4 @@
+
+difference between ps aux VS ps ef    
+ps aux - contains memory utilization %CPU, %MEM    
+<img width="1398" height="795" alt="1" src="https://github.com/user-attachments/assets/f09f691b-d4d9-4a59-8de4-4066004ec106" />

08-monitoring/README.md

@@ -9,11 +9,13 @@ Monitoring system resources is essential to ensure optimal performance, detect i
 - `top` – Real-time system monitoring
 - `htop` – Interactive process viewer (requires installation)
 - `vmstat` – Report system performance statistics
-- `free -m` – Show memory usage
+- `free -m or free -h` – Show memory usage  [memory]
+- `nproc` – number of CPU available in the machine [CPU]
 
 ### Disk Monitoring
 - `df -h` – Check disk space usage
-- `du -sh /path` – Show disk usage of a specific directory
+- `du -sh /path` – Show disk usage of a specific directory [in KB or MB]
+- `du -sh *` – Show disk usage for all the files and directories inside the specific directory [in KB or MB]
 - `iostat` – Display CPU and disk I/O statistics
 
 ### Network Monitoring
@@ -103,4 +105,4 @@ journalctl -f  # Systemd logs
 ### Checking Kernel Logs
 ```bash
 dmesg | tail
-```
+```

10-disk-management/README.md

@@ -7,7 +7,7 @@ Managing disks and storage efficiently is crucial for system performance and sta
 
 ### Viewing Disk Information
 - `lsblk` – Display block devices
-- `fdisk -l` – List disk partitions
+- `fdisk -l` – List disk partitions,same as `lsblk` but provides more info about the partition 
 - `blkid` – Show UUIDs of devices
 - `df -h` – Check disk space usage
 - `du -sh /path` – Show size of a directory