thesaadarshad

# Comprehensive Guide: TCP/IP, Networks, and Linux Commands

TCP/IP is the foundation of modern networking. This guide provides an in-depth explanation of its components, layers, and related Linux commands for system developers and network engineers.

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## 1. TCP/IP Overview

TCP/IP (Transmission Control Protocol/Internet Protocol) is a suite of communication protocols used to interconnect network devices.

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System Monitoring

    top: Real-time process and resource usage.
        Example: top
    htop: Interactive process viewer.
        Example: htop
    vmstat: System performance (CPU, memory, I/O).
        Example: vmstat 5 10
    iostat: Disk I/O and CPU usage stats.
        Example: iostat -x 1

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# Linux Commands Cheat Sheet

| **Category**         | **Command**      | **Description**                                      | **Example**                                   |
|-----------------------|------------------|------------------------------------------------------|-----------------------------------------------|
| **Process Monitoring**| `top`            | Display real-time CPU and memory usage of processes. | `top`                                         |
|                       | `htop`           | Interactive process viewer.                         | `htop`                                        |
| **System Metrics**    | `vmstat`         | Report system performance (CPU, memory, I/O, etc.). | `vmstat 5 10` (Updates every 5 seconds, 10 times) |
|                       | `iostat`         | Show CPU and disk I/O statistics.                   | `iostat -x 1` (Extended stats every second)   |
| **Logs & Kernel**     | `dmesg`          | Display boot and kernel messages.                   | `dmesg 

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################################# KUBERNETES CHEAT SHEET #############################################

########### VIEWING RESOURCE INFORMATION ###############
# nodes
kubectl get no
kubectl get no -o wide
kubectl describe no
kubectl get no -o yaml
kubectl get node --selector=[label_name]
kubectl get nodes -o jsonpath='{.items[*].status.addresses[?(@.type=="ExternalIP")].address}'

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from PIL import Image
import os
from pathlib import Path
import PIL

def convert(filepath,fixed_height=1200):
    path = Path(filepath)
    filename = filepath.split("/")[-1:][0]
    newfilebasefolder = path.parent.absolute()
    newfilename = str(newfilebasefolder)+"/"+filename

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#!/usr/bin/env python
import PIL
from PIL import Image
import os, sys

mywidth = 1200

path = "/pathtofolder/"
dirs = os.listdir( path )

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ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQC/0AC9TYx37Mdg8yi8Uju1s3tW1a5mkc9MxSICVCFYAyEhUcCclVJ9qZtpLj98I0xV6FMTeMpb7XH1m2jQfhNYL/RMHQBsrZ7D7ey/hYx+7jKImS66MCFH4KPfpJGCaDxnAqYz0Bjbb7+9EHgVo0DV/B/xQ6yyhLYVMpDOdmbDrfyBcD3modsecaSllIHnkNdcX3yklVnbwxyNjfBKNoVbZBanFIofr5Me+/uFKKAkLHbCiUkFTjTE2NxsWiHTQCE7Nfm9/ZHvBQGZAmlmP4ZCIYAspgO0MPjoz8kUWXXtm0ZewSu22NAHxHZNs8hVT7/aFC5NGIApv5E5JKawbNk9 root@saadmachine

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Each of these commands will run an ad hoc http static server in your current (or specified) directory, available at http://localhost:8000. Use this power wisely.

Discussion on reddit.

Python 2.x

$ python -m SimpleHTTPServer 8000

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import datetime

now = datetime.datetime.now()

print
print "Current date and time using str method of datetime object:"
print str(now)

print
print "Current date and time using instance attributes:"

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#!/usr/bin/python

import requests
import json
import re


url = "https://reqres.in/api/users"
querystring = { "demovar": "testvalue" }
headers = { 'auth': "FGtbAXGT4QbBLQj97j2P" }