touch ‐ #files - five4nets/Linux-Knowledgebase GitHub Wiki
Linux touch Command Tutorial
The touch command in Linux is a simple yet powerful utility used primarily to create empty files or update the timestamps of existing files. This tutorial covers the basics of the touch command, its syntax, options, and practical examples.
Table of Contents
Introduction
The touch command is commonly used to:
- Create empty files.
- Update the access and modification timestamps of existing files.
- Set specific timestamps for files.
It is a standard command available in most Linux distributions and Unix-like systems.
Syntax
touch [options] file...
file: The name of the file(s) to create or update.options: Flags that modify the command's behavior.
Common Options
| Option | Description |
|---|---|
-a |
Update only the access time. |
-m |
Update only the modification time. |
-c |
Do not create a file if it does not exist. |
-d |
Set a specific timestamp using a date string. |
-t |
Set a specific timestamp using a formatted time (e.g., YYYYMMDDhhmm). |
-r |
Use the timestamp of a reference file. |
--help |
Display the help manual for touch. |
Examples
Creating a Single File
To create an empty file named example.txt:
touch example.txt
This creates example.txt if it doesn't exist. If it already exists, it updates the file's access and modification timestamps to the current time.
Creating Multiple Files
To create multiple files at once:
touch file1.txt file2.txt file3.txt
This creates three empty files: file1.txt, file2.txt, and file3.txt.
Updating File Timestamps
To update the timestamps of an existing file to the current time:
touch existing_file.txt
This updates both the access and modification times of existing_file.txt.
Setting Specific Timestamps
To set a specific timestamp for a file using the -t option:
touch -t 202306151230 file.txt
This sets the timestamp of file.txt to June 15, 2023, 12:30 PM.
Alternatively, use the -d option with a date string:
touch -d "2023-06-15 12:30" file.txt
This achieves the same result as the previous example.
Using a Reference File
To set the timestamp of one file to match another file's timestamp:
touch -r reference_file.txt target_file.txt
This updates target_file.txt to have the same timestamps as reference_file.txt.
Creating a File Without Changing Timestamps
To update a file's timestamp only if it exists, without creating it if it doesn't:
touch -c nonexistent_file.txt
No file is created if nonexistent_file.txt does not exist.