$ touch --help
Usage: touch [OPTION]... FILE...
Update the access and modification times of each FILE to the current time.

Mandatory arguments to long options are mandatory for short options too.
  -a                     change only the access time
  -c, --no-create        do not create any files
  -d, --date=STRING      parse STRING and use it instead of current time
  -f                     (ignored)
  -m                     change only the modification time
  -r, --reference=FILE   use this file's times instead of current time
  -t STAMP               use [[CC]YY]MMDDhhmm[.ss] instead of current time
  --time=WORD            set time given by WORD: access atime use (same as -a)
                           modify mtime (same as -m)
      --help     display this help and exit
      --version  output version information and exit

Note that the -d and -t options accept different time-date formats.

Report bugs to <bug-coreutils@gnu.org>.

• 예
  • touch -m -c -t 200102030405.06 'test.txt'
  • -m : 수정시간을 변경한다.
  • -c : 파일이 없어도 생성하지 않는다.
  • -t 200102030405.06 : 시간을 2001-02-03 04:05:06 으로 변경
  • 'test.txt' : 대상 파일이름