---
title: ln — Create Links
date: 2026-10-18
time: 12:00
model: admin
category: programs
author_type: human
summary: A command for creating hard links and symbolic links. Often used for deployment directory replacement and file sharing.
tags: program, File and disk management, ln
---

**💬 "ln command"**

ln creates an **alias (link)** to a file. Without `-s`, it creates a hard link; with it, a symbolic link.

In practice, you create a **symbolic link that points to the current version** (for example, current → release-20261018) and use it for zero-downtime deployments.

- **Concept**: A link points to the same content under another name without copying the file.
- **Left column**: In `ls -l`, a symbolic link starts with `l` and shows `name -> target`.
- **Hard link**: Shares the same inode. If you delete one name, the data remains as long as another name remains.
- **Symbolic link**: A special file that contains a path. If the target disappears, it becomes a broken link.
## Common options

| Option | Description |
| --- | --- |
| -s | Creates a symbolic (soft) link — the default in practice |
| -f | Overwrites an existing link if present |
| -n | When the target is a directory link, replaces the link itself instead of the inside of the link |
| -v | Prints what was created |

## 3 essential command combinations

- `ln -sfn /opt/app/releases/20261018 /opt/app/current` — atomically replaces the current version pointer
- `ln -s /var/www/html/index.php /etc/nginx/html/index.php` — symlinks the actual file into the configuration path
- `ls -l /opt/app/current` — shows where the link points
**💬 "Tell me the order to check when you receive a real customer inquiry."**

Here are common situations you encounter on production servers, organized step by step.

### Step 1 · Prepare the new version directory

Extract the new release into a separate directory.

```
tar -xzf /tmp/release.tgz -C /opt/app/releases/20261018
```

### Step 2 · Replace the pointer

Use -sfn to change the current link to the new version. The replacement is atomic, so there is no momentary interruption.

```
ln -sfn /opt/app/releases/20261018 /opt/app/current
```

### Step 3 · Verify

Verify the link target and the service response.

```
ls -l /opt/app/current && curl -sI https://example.com | head -1
```

## How it is used in practice

### 1. Replacing the pointer for zero-downtime deployment

**Situation** — The web server points to /opt/app/current and you need to switch to a new version.

```
ln -sfn /opt/app/releases/20261018 /opt/app/current
```

**Result** — The current link points to the new release, and new requests are served with the new code.

**Point** — Compared to copying the entire directory, this causes less disruption and rollback is done with a single link change.

### 2. Sharing configuration files

**Situation** — Multiple apps need to reference the same configuration file.

```
ln -s /etc/app/common.env /srv/app1/.env
```

**Result** — Change it in one place, and it is reflected in all apps.

**Point** — Because unexpected synchronization issues can occur when apps write to the configuration, use this mainly for read-only sharing.

## Things to watch out for

- Trying to overwrite an existing link without -f fails. The -sfn combination is the safest.
- If you omit -n for a directory link, you can end up creating a link inside the link.
- Relative-path symbolic links can break depending on the working directory, so absolute paths are recommended.
- When deleting, confirm whether you are deleting only the link or also the original.
## Actual output

The result of verifying that the current link points to the new release.

![ln command execution result: verifying the symbolic link target](https://games.aidebatehub.com/assets/ln-demo.png)

Live production server

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