vi commands

Here is the complete **HTML version** of the `vi` commands guide with examples: ```html

📝 vi Editor Commands with Examples

🔹 Starting vi

vi filename

This opens filename in vi. If it doesn't exist, vi will create it when saved.

📖 Modes in vi

• Normal Mode: Default mode for navigation and commands.
• Insert Mode: For editing text.
• Command Mode: For file operations (triggered by :).

✍️ Insert Mode Commands

Command	Description
i	Insert before cursor
I	Insert at beginning of line
a	Append after cursor
A	Append at end of line
o	Open new line below
O	Open new line above
Esc	Exit insert mode

🧪 Example:

Press i → type your text → press Esc to exit insert mode.

📂 File Commands (Command Mode)

Command	Description
:w	Save the file
:q	Quit vi
:wq	Save and quit
:q!	Quit without saving
:w new.txt	Save content to new.txt

🔍 Navigation Commands

Command	Description
h	Move left
l	Move right
j	Move down
k	Move up
0	Beginning of line
$	End of line
G	End of file
gg	Start of file
:n	Go to line number n
Ctrl+d	Scroll down half page
Ctrl+u	Scroll up half page

✂️ Editing Commands

Command	Description
x	Delete character under cursor
dd	Delete current line
yy	Copy (yank) current line
p	Paste below
P	Paste above
u	Undo last change
Ctrl+r	Redo
r<char>	Replace character under cursor
R	Enter replace mode

🔍 Search and Replace

Command	Description
/word	Search forward for "word"
?word	Search backward for "word"
n	Repeat last search
:%s/old/new/g	Replace all "old" with "new"
:5,10s/foo/bar/g	Replace from line 5 to 10

✅ Practical Example

$ vi demo.txt

Then inside vi:

1. Press i and type:

Hello World
This is a test file.

2. Press Esc
3. Type :wq to save and quit

``` You can save this as `vi-commands.html` and open it in any browser. Would you like a downloadable file version or additional content like visual cheat sheets or keyboard diagrams?

jobs command

Here is the combined HTML version of both responses: the explanation of the `jobs` command and the step-by-step example. ```html

Unix jobs Command - Usage Guide

🔧 What Is a "Job" in Unix?

A job refers to a command or process started from a shell. Jobs can be:

• Foreground: Active and attached to the terminal.
• Background: Running behind the scenes.
• Stopped: Suspended with Ctrl+Z.

📘 Usage of jobs Command

jobs

This displays all jobs started from the current shell, including their ID, state, and command.

📋 Example Output

$ sleep 100 &
[1] 12345
$ jobs
[1]+  Running                 sleep 100 &

⌨️ Related Job Control Commands

Command	Description
&	Run a command in the background
Ctrl+Z	Pause (suspend) a foreground job
fg	Resume job in foreground
bg	Resume job in background
kill %1	Kill job with ID 1
jobs -l	Show job PID
jobs -p	Show job all processes

✅ When It's Useful

• Managing long-running processes during an active shell session
• Suspending/resuming tasks without killing them
• Debugging shell-based automation or accidental background tasks

🧪 Step-by-Step Example: Managing Jobs

🔹 Step 1: Start a Long-Running Command

$ sleep 300

🔹 Step 2: Suspend with Ctrl + Z

^Z
[1]+  Stopped                 sleep 300

🔹 Step 3: Check Jobs

$ jobs
[1]+  Stopped                 sleep 300

🔹 Step 4: Resume in Background

$ bg %1
[1]+ sleep 300 &

🔹 Step 5: Bring Back to Foreground

$ fg %1
sleep 300

🔹 Step 6: Kill the Job

$ jobs
[1]+  Running                 sleep 300 &

$ kill %1

$ jobs
[1]+  Terminated              sleep 300

✅ Summary

• & to run in background
• Ctrl+Z to pause
• bg / fg to resume
• kill to terminate

``` You can save this as `jobs-command.html` and open it in any web browser. Want me to include downloadable links or CSS framework enhancements?

Unix Top Command

Here's the above explanation in clean, semantic HTML format: ```html

Unix top Command - Usage Guide

🔍 What top Shows

When you run top, it displays:

1. System Summary

• uptime: How long the system has been running.
• users: Number of logged-in users.
• load average: 1, 5, and 15 minute load.
• Tasks: Total, running, sleeping processes, etc.
• CPU usage:
  • %us: user processes
  • %sy: system/kernel processes
  • %id: idle time
  • %wa: I/O wait
  • %hi: hardware interrupts
  • %si: software interrupts
  • %st: steal time (VMs)
• Memory and Swap: Total, used, free, buffers, etc.

2. Process List

Displays information per process:

• PID: Process ID
• USER: Owner
• %CPU: CPU usage
• %MEM: Memory usage
• TIME+: Total CPU time used
• COMMAND: Command name

🛠️ Common Day-to-Day Usage in Production

• Find High CPU Usage: Use P to sort by CPU usage.
• Check Memory Leaks: Use M to sort by memory usage.
• Identify Stuck or Zombie Processes: Look for state Z.
• Check Load Averages: High load may indicate system stress.
• Check I/O Wait: High %wa indicates disk bottlenecks.
• Kill a Misbehaving Process: Use k and enter PID.

🧠 Useful Keybindings in top

Key	Action
P	Sort by CPU usage
M	Sort by memory usage
k	Kill a process (enter PID)
R	Renice a process
c	Toggle full command display
1	Show all CPU cores
h	Help
q	Quit

🧪 Pro Tips

• Use top -u <username> to filter by user.
• Use top -p <PID> to monitor a specific process.
• Use htop for a more visual alternative (if installed).

``` You can save this as an `.html` file and open it in any browser. Want me to include a live example or a downloadable template?