- Authors
- Name
- Youngju Kim
- @fjvbn20031
Overview
Linux has useful tools called head and tail. By using these, you can view the beginning or end of a text file.
head document
NAME
head – display first lines of a file
SYNOPSIS
head [-n count | -c bytes] [file ...]
DESCRIPTION
This filter displays the first count lines or bytes of each of the
specified files, or of the standard input if no files are specified. If
count is omitted it defaults to 10.
The following options are available:
-c bytes, --bytes=bytes
Print bytes of each of the specified files.
-n count, --lines=count
Print count lines of each of the specified files.
If more than a single file is specified, each file is preceded by a header
consisting of the string "==> XXX <==" where "XXX" is the name of the file.
NAME
tail – display the last part of a file
SYNOPSIS
tail [-F | -f | -r] [-q] [-b number | -c number | -n number] [file ...]
DESCRIPTION
The tail utility displays the contents of file or, by default, its standard
input, to the standard output.
The display begins at a byte, line or 512-byte block location in the input.
Numbers having a leading plus ('+') sign are relative to the beginning of
the input, for example, "-c +2" starts the display at the second byte of
the input. Numbers having a leading minus ('-') sign or no explicit sign
are relative to the end of the input, for example, "-n 2" displays the last
two lines of the input. The default starting location is "-n 10", or the
last 10 lines of the input.
The options are as follows:
-b number, --blocks=number
examples
Let's assume we have a test.txt file with the following content.
$cat test.txt
chaos and order
hello
hi
nice to meet you
and you?
thankyou
1
2
3
4
4
5
6
7
hihihihihi
head file
If you enter a file name after head, it outputs the first 10 lines.
$ head test.txt
chaos and order
hello
hi
nice to meet you
and you?
thankyou
1
2
3
4
head -n file
If you specify a number with -n after head, it outputs the first n lines.
$ head -5 test.txt
chaos and order
hello
hi
nice to meet you
and you?
tail file
Opposite to head, the tail command shows text from the end.
$ tail test.txt
thankyou
1
2
3
4
4
5
6
7
hihihihihi
tail -n file
Specifying -n shows the last n lines.
$ tail -3 test.txt
6
7
hihihihihi
When reading simple text or checking what kind of text it is, it can be very useful to quickly check with tail and head.
Quiz
Q1: What is the main topic covered in "Linux head and tail Command Basics"?
Learn the basics of the head and tail commands, useful text viewing command-line tools in Linux.
Q2: What is head file?
If you enter a file name after head, it outputs the first 10 lines.
Q3: Explain the core concept of head -n file.
If you specify a number with -n after head, it outputs the first n lines.
Q4: What are the key aspects of tail file?
Opposite to head, the tail command shows text from the end.
Q5: How does tail -n file work?
Specifying -n shows the last n lines. When reading simple text or checking what kind of text it
is, it can be very useful to quickly check with tail and head.