---
title: head — Linux basic command
date: 2026-10-19
time: 12:00
model: admin
category: programs
author_type: human
summary: Outputs the beginning part (first few lines) of a file.
tags: program, Basic Linux commands, head
---

A command that prints only the beginning part (the first few lines) of a file.

## Basic Information

| Command Name | head |
| --- | --- |
| One-line Introduction | A command that prints only the beginning part (the first few lines) of a file. |
| Provided by | GNU coreutils (installed by default in all Linux distributions) |
| Official Documentation | https://man7.org/linux/man-pages/man1/head.1.html |
| Supported OS | Linux, macOS, BSD, WSL |
| Installation Status | Installed by default (no separate installation required) |
| Category | Linux Basic Command (Tags: file output, text, line count, linux, basic) |

## What is this command?

head is a command that outputs only the specified number of lines (default 10 lines) from the beginning of a file. It is used to quickly check the first part of a long file.

You can specify the number of output lines with the -n option, and also output based on the number of bytes with the -c option.

## What problem does it solve?

- Checks the beginning of a long file.
- Quickly checks header information.
- Looks at the beginning part to understand the file structure.
- Previews only the front part of a large file.
## Main Features

### Default 10-Line Output

Prints the first 10 lines of a file.

- **Use Case**: When you need to quickly grasp the file structure.
- **Result Obtained**: You can view the content at the beginning of the file.
- **Limitations**: If the file has fewer than 10 lines, the entire content is printed.
### Specify Number of Lines (-n)

Specify the number of lines to output with the -n option.

- **Use Case**: When you only want to check a specific number of lines.
- **Result Obtained**: Outputs exactly the specified number of lines.
- **Limitations**: An error occurs if a value of 0 or less is specified.
### Output by Byte Count (-c)

Outputs based on the number of bytes using the -c option.

- **Use Case**: When reading fixed-length record files.
- **Result Obtained**: Outputs the specified number of bytes.
- **Limitations**: Multi-byte characters like Hangul may be truncated.
### Simultaneous Output of Multiple Files

Outputs the beginning parts of multiple files in sequence.

- **Use Case**: When checking the beginning of multiple log files at once.
- **Result Obtained**: Outputs each file with its header.
- **Limitations**: Output can become lengthy if there are many files.
## Installation and Execution

### Verify Default Installation

It is included by default in all Linux distributions.

```
which head
head --version
```

### Installation (Lightweight Environment)

Typically already installed.

```
sudo apt install coreutils   # Debian/Ubuntu
```

## Practical Usage Examples

### Default Output

Check the first 10 lines of a file.

```
# Print the first 10 lines
cat /var/log/syslog | head

# Specify file directly
head /var/log/syslog

# Multiple files
head file1.txt file2.txt
```

### Specify Number of Lines

Outputs the desired number of lines.

```
# Only the first 5 lines
head -n 5 /var/log/syslog

# Only the first 20 lines
head -20 /var/log/syslog

# With a pipe
ps aux | head -5
```

### Output by Byte Count

Outputs based on the number of bytes.

```
# Print only the first 100 bytes
head -c 100 /var/log/syslog

# Only the first line (head -1)
head -1 /etc/passwd
```

---
Source (HTML): https://games.aidebatehub.com/programs/linux/basics/head.html
This file is an auto-generated Markdown twin of the DevHub document.