Command_drill_II

Command_drill_intermediate.sh

#######
#Pipes#
#######
#Download the contents of "Harry Potter and the Goblet of fire" using the command line
wget https://raw.githubusercontent.com/bobdeng/owlreader/master/ERead/assets/books/Harry%20Potter%20and%20the%20Goblet%20of%20Fire.txt


#Print the first three lines in the book
#using awk
cat "Harry Potter and the Goblet of Fire.txt" | awk 'FNR==1,FNR==3'
#using head
cat "Harry Potter and the Goblet of Fire.txt" | head -3


#Print the last 10 lines in the book
cat "Harry Potter and the Goblet of Fire.txt" | tail -10


#How many times do the following words occur in the book?
#Harry
cat "Harry Potter and the Goblet of Fire.txt" | grep -c Harry      #2591
#Ron
cat "Harry Potter and the Goblet of Fire.txt" | grep -c Ron        #947
#Hermione
cat "Harry Potter and the Goblet of Fire.txt" | grep -c Hermione   #822
#Dumbledore
cat "Harry Potter and the Goblet of Fire.txt" | grep -c Dumbledore #507


#Print lines from 100 through 200 in the book
cat "Harry Potter and the Goblet of Fire.txt" | awk 'FNR==100,FNR==200'


#How many unique words are present in the book?
cat "Harry Potter and the Goblet of Fire.txt" | awk '{ for(freq = 1; freq <= NF; freq++) {words[$freq]++} } END { for(freq in words) if(words[freq] == 1) { uwc++ } print uwc }'
#12540


###################
# Processes, ports#
###################
#List your browser's process ids (pid) and parent process ids(ppid)
pgrep brave
#52071 (pid)
#52081 (pid)
#52091 (pid)
#52092 (pid)
#52094 (pid)
#52117 (pid)
#52118 (pid)
#52147 (pid)
#52165 (pid)
#52296 (pid)
#52452 (pid)
#52544 (pid)
#57738 (pid)
#92612 (pid)
#92681 (pid)
#95526 (pid)
#98454 (pid)
#99258 (pid)
#99531 (ppid)


#Stop the browser application from the command line
pkill brave


#List the top 3 processes by CPU usage.
ps -eo pid,ppid,comm,%mem,%cpu --sort=-%cpu | head -4
# top 4 are taken because it also includes coloumn name i.e pid, ppid, command, memory used, cpu usage


#Start a Python HTTP server on port 8000
python -m http.server 8000


#Open another tab. Stop the process you started in the previous step
kill $(ps -e | grep python | awk '{print $1}')


#Start a Python HTTP server on port 90
sudo python -m http.server 90


# Display all active connections and the corresponding TCP / UDP ports.
netstat -atu


Find the pid of the process that is listening on port 5432
netstat -ltnup | grep ':5432'



###################
#Managing software#
###################
#Install htop
sudo apt install htop

#Install vim
sudo apt install vim

#Install nginx
sudo apt install nginx

#Uninstall nginx
sudo apt remove nginx



##################
# Mmiscellaneous #
##################

#What's your local IP address?
hostname -I

#Find the IP address of google.com
host google.com

#How to check if Internet is working using CLI?
ping -c 2 google.com

#Where is the node command located? 
which node

#What about code?
which code