notes/session-03.txt at main · daws-88s/notes · GitHub

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absolute path
relative path

/c/devops/daws-88s/daws-88s -> absolute
daws-88s/daws-88s -> relative

cd -> change directory
clear
$ -> normal user
/home/ec2-user -> /home/<user-name>

sudo su -> root access
# -> super user

/root -> root user home directory

everything is command and text in linux

command-name <inputs> <options>

<inputs> <options> -> optional or mandatory based on the command

uname -> print os/kernel infromation
uname --help or man uname

CRUD -> create read update delete

ls -> list subdirectories
ls -l -> long format alphabetical order.. file/folder who owns it, size, timestamp
ls -lr
ls -lt -> latest files on top
ls -ltr -> latest files at bottom
cd -> to home directory from wherever you are

hidden files/folders start with .

ls -lart -> hidden files and folders

d rwx r-x r-x -> directory
- rwx r-x r-x -> file

cat > devops.txt -> enter the text you want

Press Enter and Ctrl+d

cat filename -> read the content in the file

> -> redirection, usually overrides the previous text
>> -> appends to the previous text

source -> which file to copy
destination -> destination

cp <source> <destination>
cp

mv -> rename or move the file

downloading files or softwares

wget and curl

https://dlcdn.apache.org/tomcat/tomcat-9/v9.0.113/bin/apache-tomcat-9.0.113.tar.gz

wget is used for downloading packages
curl -> shows the o/p on the screen, it will not download by default
curl is used to hit the API URL's

grep -> command to search inside the file

grep <word-to-search> <file>
-i -> case insensitive
-v -> non matching
-n -> display line numbers
-c -> matching line numbers count

display line number ending with the word architecture

$ -> ending charecter
^ -> starting charecter

ctrl + r start typing you can see the commands you used

$ -> ending
^ -> starting

tail -f <file-name> -> follow the log

head -> top 10 lines by default
tail -> bottom 10 lines by default

cut and awk

https://raw.githubusercontent.com/daws-88s/notes/refs/heads/main/session-02.txt

cut -d "/" -f1 <file-name>

/etc/passwd

awk -F "/" '{print $NF}'


Tomorrow's session
==================
vim editor
user management