---
title: touch — Create files and update timestamps
date: 2026-10-18
time: 12:00
model: admin
category: programs
author_type: human
summary: Command that creates an empty file or updates the modification time of an existing file. Used for deployment triggers and checks.
tags: program, File and disk management, touch
---

**💬 "touch command"**

touch **creates an empty file**, and if the file already exists, it only updates the modification time. It does not touch file contents.

In practice, it is often used as a **configuration reload trigger** or a deployment marker file.

- **Concept**: If the file does not exist, it is created as 0 bytes; if it exists, the access/modification time is updated to the current time.
- **Left column**: The created file name is generated as-is.
- **Right column**: For an existing file, the contents remain the same and only the Modify time changes.
- **Specifying a time**: You can specify the desired time with the -t and -d options.
## Commonly used options

| Option | Description |
| --- | --- |
| -c | Update the timestamp only when the file already exists; do not create a new file |
| -t [[CC]YY]MMDDhhmm[.ss] | Set to a specific time |
| -d 'string' | Specify the time in a human-readable format |
| -a / -m | Update only the access time / only the modification time |

## 3 essential command combinations

- `touch /var/www/html/reload.txt` — Update the file the app watches to trigger a reload
- `touch -c /opt/app/current/public/index.php` — Update the timestamp only if the file exists (prevents mistakes)
- `touch -d '2026-10-18 02:00' /tmp/marker` — Create a marker file with a specific timestamp
**💬 "Show me the verification procedure in a rehearsal environment"**

These are common situations on live production servers, organized in order.

### Step 1 · Create a marker file

Create a file to record the deployment time.

```
touch /opt/app/releases/20261018/.deployed
```

### Step 2 · Reload trigger

Trigger a reload in an environment with a configuration watcher.

```
touch /etc/nginx/.reload
```

### Step 3 · Verification

Check that the timestamp was updated.

```
stat -c '%n %y' /etc/nginx/.reload
```

## How it is used in practice

### 1. Zero-downtime reload trigger

**Situation** — PHP-FPM detects configuration changes by file timestamp.

```
touch /etc/php/8.3/fpm/php.ini
```

**Result** — The configuration watcher re-reads the file even without content changes.

**Point** — Useful when you need to force a reapply even if the configuration content has not changed.

### 2. Mark deployment status

**Situation** — After deploying to multiple servers, you need to check which server is up to date.

```
touch /srv/app/.deploy-20261018 && stat -c '%y' /srv/app/.deploy-20261018
```

**Result** — You can record each server's deployment time in a file and compare them.

**Point** — If monitoring reads the file existence/timestamp, you can automatically inspect deployment status.

## Cautions

- The year format for -t is often confusing between two-digit and four-digit years. -d is easier to read for specifying times.
- Arbitrarily changing the timestamp of production files can confuse backup tools (incremental backups).
- If you mistype a path without -c, an empty file will be created in the wrong location.
## Actual execution output

This is the result of creating a marker file and checking its timestamp.

![touch command execution result: empty file creation and timestamp check](https://games.aidebatehub.com/assets/touch-demo.png)

Live production server

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