[Linux] Bash head Usage: Display the beginning of files

Overview

The head command in Bash is used to display the first few lines of a file or the output of a command. By default, it shows the first 10 lines, but this can be adjusted with options.

Usage

The basic syntax of the head command is as follows:

head [options] [arguments]

Common Options

• -n [number]: Specify the number of lines to display. For example, -n 5 will show the first 5 lines.
• -c [number]: Display the first specified number of bytes instead of lines.
• -q: Suppress the output of the file headers when multiple files are being processed.
• -v: Always show the file header, even when only one file is being processed.

Common Examples

Here are some practical examples of using the head command:

1. Display the first 10 lines of a file:

   head filename.txt
   

2. Display the first 5 lines of a file:

   head -n 5 filename.txt
   

3. Display the first 20 bytes of a file:

   head -c 20 filename.txt
   

4. Display the first 10 lines of multiple files:

   head file1.txt file2.txt
   

5. Always show the file header when displaying the first 10 lines of a file:

   head -v filename.txt
   

Tips

• Use head in combination with other commands using pipes. For example, to see the first 10 lines of a long directory listing:

  ls -l | head
  

• When working with large files, head can quickly give you a preview without opening the entire file.
• Remember that you can adjust the number of lines displayed with the -n option to suit your needs.