Head command in Linux with examples

It is the complementary of Tail command. The head command, as the name implies, print the top N number of data of the given input. By default, it prints the first 10 lines of the specified files. If more than one file name is provided then data from each file is preceded by its file name.

Syntax:

head [OPTION]... [FILE]...

Let us consider two files having name state.txt and capital.txt contains all the names of the Indian states and capitals respectively.



$ cat state.txt
Andhra Pradesh
Arunachal Pradesh
Assam
Bihar
Chhattisgarh
Goa
Gujarat
Haryana
Himachal Pradesh
Jammu and Kashmir
Jharkhand
Karnataka
Kerala
Madhya Pradesh
Maharashtra
Manipur
Meghalaya
Mizoram
Nagaland
Odisha
Punjab
Rajasthan
Sikkim
Tamil Nadu
Telangana
Tripura
Uttar Pradesh
Uttarakhand
West Bengal

Without any option, it displays only the first 10 lines of the file specified.
Example:

$ head state.txt
Andhra Pradesh
Arunachal Pradesh
Assam
Bihar
Chhattisgarh
Goa
Gujarat
Haryana
Himachal Pradesh
Jammu and Kashmir

Options

1. -n num: Prints the first ‘num’ lines instead of first 10 lines. num is mandatory to be specified in command otherwise it displays an error.

$ head -n 5 state.txt
Andhra Pradesh
Arunachal Pradesh
Assam
Bihar
Chhattisgarh

2. -c num: Prints the first ‘num’ bytes from the file specified. Newline count as a single character, so if head prints out a newline, it will count it as a byte. num is mandatory to be specified in command otherwise displays an error.

$ head -c 6 state.txt
Andhra

3. -q: It is used if more than 1 file is given. Because of this command, data from each file is not precedes by its file name.

Without using -q option
==> state.txt  capital.txt <==
Hyderabad
Itanagar
Dispur
Patna
Raipur
Panaji
Gandhinagar
Chandigarh
Shimla
Srinagar


With using -q option
$ head -q  state.txt capital.txt
Andhra Pradesh
Arunachal Pradesh
Assam
Bihar
Chhattisgarh
Goa
Gujarat
Haryana
Himachal Pradesh
Jammu and Kashmir
Hyderabad
Itanagar
Dispur
Patna
Raipur
Panaji
Gandhinagar
Chandigarh
Shimla
Srinagar

4. -v: By using this option, data from the specified file is always preceded by its file name.

$ head -v state.txt
==> state.txt <==
Andhra Pradesh
Arunachal Pradesh
Assam
Bihar
Chhattisgarh
Goa
Gujarat
Haryana
Himachal Pradesh
Jammu and Kashmir

Applications of head Command

  1. Print line between M and N lines: For this purpose we use head, tail and pipeline(|) commands. Command is: head -M file_name | tail -(M-N), since the first line takes first M lines and tail command cuts (M-N)Lines starting from the end. Let say from state.txt file we have to print lines between 10 and 20.
    $ head -n 20 state.txt | tail -10
    Jharkhand
    Karnataka
    Kerala
    Madhya Pradesh
    Maharashtra
    Manipur
    Meghalaya
    Mizoram
    Nagaland
    Odisha
    
  2. How to use the head with pipeline(|): The head command can be piped with 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.
    Display all recently modified or recently used files.
    $ ls -t
    e.txt 
    d.txt
    c.txt
    b.txt  
    a.txt
    
    Cut three most recently used file.
    $ ls -t | head -n 3
    e.txt
    d.txt
    c.txt
    
    

    It can also be piped with one or more filters for additional processing. For example, the sort filter could be used to sort the three most recently used files or folders in the alphabetic order.

    $ ls -t | head -n 3 | sort
    c.txt
    d.txt
    e.txt
    

    There are number of other filters or commands along which we use head command. Mainly, it can be used for viewing huge log files in Unix.

This article is contributed by Akash Gupta. If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

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Improved By : Akanksha_Rai