touch : change file timestamps
[SYNOPSIS] touch OPTION FILE
OPTION
-a change only the access time
-c do not create any files
-d STRING parse STRING and use it instead of current time
-m change only the modification time
-r FILE use this file's times instead of current time
-t STAMP use [[CC]YY]MMDDhhmm[.ss] instead of current time
--help display this help and exit