touch command

touch - Create empty files or update the timestamps of existing files.

Changes the shell working directory.

Usage: touch [OPTION]... [FILE]...

• OPTION: Flags which enhances the touch abilities.
• FILE: The file you want to create or modify.

Examples

• Creating a new file

  The most common use of touch is to create an empty file if it doesn’t already exist.

  $ touch myfile.txt
  • Creates an empty file named myfile.txt in the current directory.
  • If myfile.txt already exists, its last modified timestamp is updated to the current time.

• Creating multiple files

  You can create multiple files at once by listing them.

  $ touch file1.txt file2.txt file3.txt
  • Creates three empty files: file1.txt, file2.txt, and file3.txt.
  • If file1.txt, file2.txt, and file3.txt already exists, its last modified timestamp is updated to the current time.

• Setting a Specific Timestamp

  We can set a custom timestamp using the -t option, instead of using the current time.

  $ touch -t 202306060600.00 myfile.txt
  • Sets the timestamp to December 25, 2023, 12:30:00.
  • Format: YYYYMMDDHHMM.SS (year, month, day, hour, minute, seconds).

• Only update access time

  Use -a to update only the access timestamp (when the file was last read).

  $ touch -a myfile.txt
  • Changes the access time without affecting the modification time.

• Only update modification time

  Use -m to update only the modification timestamp (when the file was last changed).

  $ touch -m myfile.txt
  • Changes the modification time without affecting the access time.

• Copy the timestamp from another file as a reference file with the -r (reference) option.

  $ touch -r source.txt target.txt
  • Sets the timestamp of target.txt to match source.txt

• Preventing file creation

  Use -c (no-create) to update timestamps only if the file exists, without creating it.

  $ touch -c nonexistent.txt
  • Does nothing since nonexistent.txt doesn’t exist.

To get help related to the touch command use --help option

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

A FILE argument that does not exist is created empty, unless -c or -h
is supplied.

A FILE argument string of - is handled specially and causes touch to
change the times of the file associated with standard output.

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)
  -h, --no-dereference   affect each symbolic link instead of any referenced
                         file (useful only on systems that can change the
                         timestamps of a symlink)
  -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        change the specified time:
                           WORD is access, atime, or use: equivalent to -a
                           WORD is modify or mtime: equivalent to -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.