The head command is used to print the few first lines (by default 10 lines) of file or standard output. This tutorial shows you how to use the Linux head command with practical examples.
Head Command Syntax
Below is the basic syntax for the head command:
head [OPTION]... [FILE]...
Here,
OPTION– You can pass the head options for different actions.FILE– Pass here file name. If not passed anything head will read the standard input.
Use of Head Command
When you used head command without any option it will show the first 10 lines by default like below:
head filename
Display a Specific Number of Lines
To display the specific the number of lines, use the -n (--lines) option followed by the integer number.
head -n filename
For example, to show the first 25 lines from a file readme.md, you would run:
head -n 25 readme.md
Another way is, you can remove the n and just use the hyphen (-) and the number without space between them.
Below command will give the same output as the previous example:
head -25 readme.md
Show Specific Number of Bytes
Use the -c (--bytes) option to display a specific number of bytes:
head -c filename
For instance, to print the first 150 bytes of data of a file readme.md, run:
head -c 150 readme.md
You also can use the multiplier to specify the number of bytes. b multiplies it by 512, kB multiplies it by 1000, K multiplies it by 1024, MB multiplies it by 1000000, M multiplies it by 1048576, and so on.
In following example, it will show the first 3 kilobytes of the file readme.md:
head -c 5k readme.md
Display Multiple Files
When the multiple files are given with the head command, it will display the first 10 lines of each files.
head filename1 filename2
You can use the same options as a single file. For example to show the first 15 lines of the files readme.md and license.txt:
head -n 15 readme.md license.txt
If multiple files given then each file name is showing as header in output.
Use Head with Other Commands
The head command can be piped with other commands by redirecting the standard output from other commands.
In the following example, the output of the ls command is piped to head to show only the three most recently modified files or folders.
ls -t | head -n 3
about.php contact.php index.php
Conclusion
This guide shown you how to use the Head command in Linux with different options.
If you have any question or feedback, feel free to leave a comment below.