Hi guys! In previous article, I described you about some
basic commands and editors of Linux. If you are new to this series you can read
that from below link-
Most of us are well familiar with windows OS. Linux is also
good platform. If you will start working on it, you will realize it.
Note : Most of the issues in Big Data came from Linux
security section. I will try to cover it too. Today we will learn new topics
under Linux basics. Be careful, Linux is case sensitive.
echo command:
This is used to
print some statements.
Eg.
user@machine:~$echo “This is sample statement by vimal”
We have few concepts for defining and saving standard input, output and
error.
0 – for standard input
1 – for standard output
2 – for standard error
Please look into below image to understand it -
Mail command:
To send a mail, we will use mail command.
user@machine:~$ mail –s”This is subject” user<messagebody.txt
grep command:
grep is searching finding
filtering tool. It can do things like pattern matching & mapping
eg. user@machine:~$ grep
sometext file.txt
user@machine:~$ grep sometext ./*
user@machine:~$ grep sometext ./* |
unique | cut –d: -f1
Pipes &
Directional operators:
è
user@machine:~$Program1 | Program2
§
This means output of program1 works as input for
program2
§
Eg.
§
user@machine:~$ ps aux (to check processes)
§
user@machine:~$ ps aux | less | uniq | sort
è
user@machine:~$Program1 && Program2
§
This means when program1 true then program2
execute
§
Eg.
§
user@machine:~$ ls filenotexist.txt &&
echo “Unsuccessful”
Package management
with apt-get:
apt-get
mainly used for installation of softwares, packages
§
user@machine:~$ apt-get update
o
It may prompt permission denied. To avoid this
we will use-
§
user@machine:~$ sudo apt-get update
§
user@machine:~$ sudo apt-get upgrade
§
user@machine:~$ sudo apt-get install <applicationname>
o
To install any software or application
§
user@machine:~$ apt-cache search editor
o
To find editor
§
user@machine:~$ sudo apt-get remove <applicationname>
o
To remove software or application
