Linux Pocket Guide, 2nd Edition

Name

touch — stdin  stdout  - file  -- opt  --help  --version

Synopsis

touch [options] files

The touch command changes two timestamps associated with a file: its modification time (when the file’s data was last changed) and its access time (when the file was last read). To set both timestamps to right now, run:

$ touch myfile

You can set these timestamps to arbitrary values, e.g.:

$ touch -d "November 18 1975" myfile

If a given file doesn’t exist, touch creates it, a handy way to create empty files.

Useful options

-a	Change the access time only.
-m	Change the modification time only.
-c	If the file doesn’t exist, don’t create it (normally, touch creates it).
-d timestamp	Set the file’s timestamp(s). A tremendous number of timestamp formats are acceptable, from “12/28/2001 3pm” to “28-May” (the current year is assumed, and a time of midnight) to “next tuesday 13:59” to “0” (midnight today). Experiment and check your work with stat. Full documentation is available from info touch.
-t timestamp	A less intelligent way to set the file’s timestamp, using the format [[CC]YY]MMDDhhmm [.ss], where CC is the two-digit century, YY is the two-digit year, MM is the 2-digit month, DD is the two-digit day, hh is the two-digit hour, mm is the two-digit minute, and ss is the two-digit second. For example, -t 20030812150047 represents August 12, 2003, at 15:00:47.