HEAD command is print the number of lines or data of the given input. Default head command print the first 10 lines of each file. This post explains few different usage head command,

1. Default print 10 lines:

The below command print first 10 files or directories,

# ls | head


index.txt

test.txt

name.txt

30.11.2014+J.C.Bose.jpg

bc-1.06.95-921.2.x86_64.rpm

bcel-5.2-7.2.el6.x86_64.rpm

config.json

cront.txt

linuxfaq.txt

thelinux.txt


2. Print N number of Lines

Print first three files or directories,
 
# ls | grep head -3

To count listing number of lines,
 
# ls | head | wc -l
10

For example i have created a file test.txt with few lines,

3. Print All Lines from the File.

Below command print all lines from the file,
 
# head test.txt


Linux

CentOS

RedHat

Fedora

Ubuntu


4. Print First 2 Lines:

The below command print first 2 lines from the file,
 
# head -n 2 test.txt


Linux

CentOS

or
 
# head -2 test.txt

5. Print Except last N lines

The command Print all lines except last 2 lines,
 
# head -n -2 test.txt


Linux

CentOS

RedHat


6. Print the N number of bytes

Use -c option to print the N number of bytes,
 
# head -c 4 test.txt
Linu


7. Sepcific line:

If you would like to display "RedHat" line from the test.txt file,
 
# cat test.txt  | head -3 | tail -1
RedHat


Also, like to print first 3 letter "Red"
 
# cat test.txt  | head -3 | tail -1 | head -c -4
Red