Using sed with examples

Stream editor in short is called sed is a very powerful command which can do a lot for you when used appropriately.
Here we'll see how it can be used

1.Usage
sed [options] 'instruction[s]' file[s]

2. Print the first line of the file
[bsurnida@localhost ~]$ sed -n '1 p' animals.txt
i hate cats

[bsurnida@localhost ~]$ cat animals.txt
i hate cats
ther is a cat
cat is not here

3.Print selected range of lines from a file
[bsurnida@localhost ~]$ sed -n '1,3 p' animals.txt
i hate cats
ther is a cat
cat is not here

4.Print last line of the file
[bsurnida@localhost ~]$ sed -n '$p' animals.txt
elephant is the biggest animal

5.exclude a set of lines
[bsurnida@localhost ~]$ sed -n '1,3!p' animals.txt
a cat cant exits
here is a black cAT
no he is not taking cat exam

6.print lines containing a word (something like grep)
[bsurnida@localhost ~]$ sed -n '/cat/p' animals.txt
i hate cats
ther is a cat
cat is not here
a cat cant exits

7. Delete the blank lines from the document
[bsurnida@localhost ~]$ sed -e '/^$/d' animals.txt
Option d for delete

8.redirect the output to a new file
bsurnida@localhost ~]$ sed -e '/^$/d' animals.txt > new_animals.txt

9.search and replace using sed
bsurnida@localhost ~]$ sed -ne 's///p'
Option n for silent output , no extra lines in the new file

10.In place editing of a file and file backup
bsurnida@localhost ~]$ sed -i.bak -e 's/3/4' sed1.txt