touch - macOS

Overview

touch is a command-line tool that creates or updates a file’s timestamp, but does not modify the file’s contents. It is often used to create empty files or update existing files without modifying their contents.

Syntax

touch [-a|-c|-m|-r file] [-t time] [-d date] [file ...]

Options/Flags

-a: Access time is changed instead of modification time.
-c: Do not create any files, but only change timestamps of existing files.
-m: Modification time is changed instead of access time.
-r file: Use the timestamps of the specified file as the new timestamps for the target files.
-t time: Use the specified time (in YYYYMMDDhhmmss format) as the new timestamps.
-d date: Use the specified date (in MMDDhhmmYYYY format) as the new timestamps.

Examples

Create an empty file named myfile.txt:

touch myfile.txt

Update the modification time of file.txt to the current time:

touch -m file.txt

Create a new file newfile.txt with the same timestamps as oldfile.txt:

touch -r oldfile.txt newfile.txt

Update the access time of test.txt to one hour ago:

touch -a -t "-1hour" test.txt

Common Issues

Permission denied error: Ensure you have write permissions to the target file or directory.
Invalid time format error: Time and date formats must follow the specified YYYYMMDDhhmmss and MMDDhhmmYYYY formats, respectively.

Integration

touch can be integrated with other commands for automation tasks, such as:

Combine with find to update timestamps of all files in a directory:

find . -exec touch -m {} \;

Use with xargs to process multiple files at once:

ls | xargs touch -m