How to create files or modify file metadata with Linux touch command

Main picture of the post. How to create files or modify file metadata with Linux touch command.

The touch is one of the most basic Linux commands for empty file creation and for changing the file metadata timestamps. You normally don’t need to install it specifically because it comes with the Linux system.

The touch syntax command

The command syntax is:

touch [OPTION]… FILE…

The options available for the command are:

-a : For changing the access timestamp of the file

–c : Don’t create the file if it doesn’t exist

-d : Set specific timestamp with date string

-m : For changing only the modify timestamp

-h : Change the symbolic link file timestamp only instead of the referenced file

-r : Use the timestamp of another file

-t : Use timestamp format [[CC]YY]MMDDhhmm[.ss]

As many other Linux commands, all the options above can be combined in order to get the specific desired results.

In the following sections, we will use some of the touch command options to show how do they work.

Using touch without options

The usage of the command is easy and you can run it without options to create a void file in a target path if it doesn’t exist:

$ touch test
$ ls -l
total 0
-rw-rw-r--. 1 fse fse 0 Jun  4 11:51 test

The default behaviour is to create a file if it doesn’t exists however, you may use the “-c” option with the touch command just to modify the metadata of a target file but avoid creating the file if it doesn’t exists:

$ ls -l
total 0
-rw-rw-r--. 1 fse fse 0 Jun  4 11:51 test
$ touch -c test2
$ ls -l
total 0
-rw-rw-r--. 1 fse fse 0 Jun  4 11:51 test

As you may notice, the execution of touch command with “-c” avoided the creation of file “test2”

Changing access and modify dates in files or folders

Before explaining this use case, let’s speak about the command stat which is useful to get the metadata information of a file.

$ ls -l
total 0
-rw-rw-r--. 1 fse fse 0 Jun  4 11:51 test
$ stat test
  File: ‘test’
  Size: 0               Blocks: 0          IO Block: 4096   regular empty file
Device: fd00h/64768d    Inode: 101141036   Links: 1
Access: (0664/-rw-rw-r--)  Uid: ( 1001/     fse)   Gid: ( 1001/     fse)
Context: unconfined_u:object_r:user_home_t:s0
Access: 2022-06-04 11:51:43.324716963 +0200
Modify: 2022-06-04 11:51:43.324716963 +0200
Change: 2022-06-04 11:51:43.324716963 +0200
 Birth: -

In the above block, you may see the “Modify” and the “Access” dates on the last lines of the command output. To modify only the “Access” date the “-a” option is used:

$ stat test
  File: ‘test’
  Size: 0               Blocks: 0          IO Block: 4096   regular empty file
Device: fd00h/64768d    Inode: 101141036   Links: 1
Access: (0664/-rw-rw-r--)  Uid: ( 1001/     fse)   Gid: ( 1001/     fse)
Context: unconfined_u:object_r:user_home_t:s0
Access: 2022-06-04 11:51:43.324716963 +0200
Modify: 2022-06-04 11:51:43.324716963 +0200
Change: 2022-06-04 11:51:43.324716963 +0200
 Birth: -
$ touch -a test
$ stat test
  File: ‘test’
  Size: 0               Blocks: 0          IO Block: 4096   regular empty file
Device: fd00h/64768d    Inode: 101141036   Links: 1
Access: (0664/-rw-rw-r--)  Uid: ( 1001/     fse)   Gid: ( 1001/     fse)
Context: unconfined_u:object_r:user_home_t:s0
Access: 2022-06-04 12:12:10.434278078 +0200
Modify: 2022-06-04 11:51:43.324716963 +0200
Change: 2022-06-04 12:12:10.434278078 +0200
 Birth: -

On the other hand, if you just want to change the “Modify” date, then the “-m” option is used:

$ stat test
  File: ‘test’
  Size: 0               Blocks: 0          IO Block: 4096   regular empty file
Device: fd00h/64768d    Inode: 101141036   Links: 1
Access: (0664/-rw-rw-r--)  Uid: ( 1001/     fse)   Gid: ( 1001/     fse)
Context: unconfined_u:object_r:user_home_t:s0
Access: 2022-06-04 12:12:10.434278078 +0200
Modify: 2022-06-04 11:51:43.324716963 +0200
Change: 2022-06-04 12:12:10.434278078 +0200
 Birth: -
$ touch -m test
$ stat test
  File: ‘test’
  Size: 0               Blocks: 0          IO Block: 4096   regular empty file
Device: fd00h/64768d    Inode: 101141036   Links: 1
Access: (0664/-rw-rw-r--)  Uid: ( 1001/     fse)   Gid: ( 1001/     fse)
Context: unconfined_u:object_r:user_home_t:s0
Access: 2022-06-04 12:12:10.434278078 +0200
Modify: 2022-06-04 12:15:47.783780249 +0200
Change: 2022-06-04 12:15:47.783780249 +0200
 Birth: -
[fse@fse ~]$

If you run the touch command without options, then the command will change both “Access” and “Modify” dates:

$ date
Sat Jun  4 12:19:17 CEST 2022
$ ls -l
total 0
-rw-rw-r--. 1 fse fse 0 Jun  4 12:15 test
$ stat test
  File: ‘test’
  Size: 0               Blocks: 0          IO Block: 4096   regular empty file
Device: fd00h/64768d    Inode: 101141036   Links: 1
Access: (0664/-rw-rw-r--)  Uid: ( 1001/     fse)   Gid: ( 1001/     fse)
Context: unconfined_u:object_r:user_home_t:s0
Access: 2022-06-04 12:12:10.434278078 +0200
Modify: 2022-06-04 12:15:47.783780249 +0200
Change: 2022-06-04 12:15:47.783780249 +0200
 Birth: -
$ touch test
$ stat test
  File: ‘test’
  Size: 0               Blocks: 0          IO Block: 4096   regular empty file
Device: fd00h/64768d    Inode: 101141036   Links: 1
Access: (0664/-rw-rw-r--)  Uid: ( 1001/     fse)   Gid: ( 1001/     fse)
Context: unconfined_u:object_r:user_home_t:s0
Access: 2022-06-04 12:19:33.904423756 +0200
Modify: 2022-06-04 12:19:33.904423756 +0200
Change: 2022-06-04 12:19:33.904423756 +0200
 Birth: -

How about the folders? Well, they cannot be created with touch, nevertheless, it’s metadata can be modified anyway:

$ date
Sat Jun  4 13:07:54 CEST 2022
[fse@fse ~]$ ls -l
total 0
drwxrwxr-x. 2 fse fse 6 Feb 27  2011 files
$ stat files
  File: ‘files’
  Size: 6               Blocks: 0          IO Block: 4096   directory
Device: fd00h/64768d    Inode: 356130      Links: 2
Access: (0775/drwxrwxr-x)  Uid: ( 1001/     fse)   Gid: ( 1001/     fse)
Context: unconfined_u:object_r:user_home_t:s0
Access: 2022-06-04 13:04:20.405194702 +0200
Modify: 2011-02-27 15:15:33.000000000 +0100
Change: 2022-06-04 13:04:35.094432650 +0200
 Birth: -
$ touch files
$ ls -l
total 0
drwxrwxr-x. 2 fse fse 6 Jun  4 13:08 files
$ stat files
  File: ‘files’
  Size: 6               Blocks: 0          IO Block: 4096   directory
Device: fd00h/64768d    Inode: 356130      Links: 2
Access: (0775/drwxrwxr-x)  Uid: ( 1001/     fse)   Gid: ( 1001/     fse)
Context: unconfined_u:object_r:user_home_t:s0
Access: 2022-06-04 13:08:07.708876753 +0200
Modify: 2022-06-04 13:08:07.708876753 +0200
Change: 2022-06-04 13:08:07.708876753 +0200
 Birth: -

As you may appreciate, the touch command by default will set access and modify dates with the current date but, what if you want to place a specific date? This will be explained in the next section.

Setting a specific access or modify date in a file

Until now, we have explored how to change the timestamp dates with the current date but, one of the interesting usages of touch is to change those metadata timestamps to a custom date. In order to do that, the options “-d”, “-t” or “-r” are used depending of what date format you want to pass.

In the following example, the touch command will change the access date only to a specific custom date using a date string (-d option):

$ date
Sat Jun  4 12:26:58 CEST 2022
$ stat test
  File: ‘test’
  Size: 0               Blocks: 0          IO Block: 4096   regular empty file
Device: fd00h/64768d    Inode: 101141036   Links: 1
Access: (0664/-rw-rw-r--)  Uid: ( 1001/     fse)   Gid: ( 1001/     fse)
Context: unconfined_u:object_r:user_home_t:s0
Access: 2022-06-04 12:19:33.904423756 +0200
Modify: 2022-06-04 12:19:33.904423756 +0200
Change: 2022-06-04 12:19:33.904423756 +0200
 Birth: -
$ touch -a -d "2015-01-27 11:27:27.000000000" test 
$ stat test
  File: ‘test’
  Size: 0               Blocks: 0          IO Block: 4096   regular empty file
Device: fd00h/64768d    Inode: 101141036   Links: 1
Access: (0664/-rw-rw-r--)  Uid: ( 1001/     fse)   Gid: ( 1001/     fse)
Context: unconfined_u:object_r:user_home_t:s0
Access: 2015-01-27 10:27:27.000000000 +0100
Modify: 2022-06-04 12:19:33.904423756 +0200
Change: 2022-06-04 12:29:10.845802781 +0200
 Birth: -

The same can be done with the modify timestamp but, in this example, we’ll use the “-t” option:

$ date
Sat Jun  4 12:34:18 CEST 2022
$ stat test
  File: ‘test’
  Size: 0               Blocks: 0          IO Block: 4096   regular empty file
Device: fd00h/64768d    Inode: 101141036   Links: 1
Access: (0664/-rw-rw-r--)  Uid: ( 1001/     fse)   Gid: ( 1001/     fse)
Context: unconfined_u:object_r:user_home_t:s0
Access: 2015-01-27 11:27:27.000000000 +0100
Modify: 2022-06-04 12:19:33.904423756 +0200
Change: 2022-06-04 12:29:32.678159145 +0200
 Birth: -
$ touch -m -t 201102271515.33 test
$ stat test
  File: ‘test’
  Size: 0               Blocks: 0          IO Block: 4096   regular empty file
Device: fd00h/64768d    Inode: 101141036   Links: 1
Access: (0664/-rw-rw-r--)  Uid: ( 1001/     fse)   Gid: ( 1001/     fse)
Context: unconfined_u:object_r:user_home_t:s0
Access: 2015-01-27 11:27:27.000000000 +0100
Modify: 2011-02-27 15:15:33.000000000 +0100
Change: 2022-06-04 12:36:12.207680457 +0200
 Birth: -
$ ls -l
total 0
-rw-rw-r--. 1 fse fse 0 Feb 27  2011 test

An alternate to get a specific date is to get it from another file by using the option “-r”. So, in the next block both access and modify timestamps will be override with the same values as the other file:

$ date
Sat Jun  4 12:42:19 CEST 2022
$ stat /etc/hosts
  File: ‘/etc/hosts’
  Size: 208             Blocks: 8          IO Block: 4096   regular file
Device: fd00h/64768d    Inode: 33554825    Links: 1
Access: (0644/-rw-r--r--)  Uid: (    0/    root)   Gid: (    0/    root)
Context: system_u:object_r:net_conf_t:s0
Access: 2022-06-04 10:37:50.880289006 +0200
Modify: 2022-06-04 10:37:48.794362409 +0200
Change: 2022-06-04 10:37:48.794362409 +0200
 Birth: -
$ stat test
  File: ‘test’
  Size: 0               Blocks: 0          IO Block: 4096   regular empty file
Device: fd00h/64768d    Inode: 101141036   Links: 1
Access: (0664/-rw-rw-r--)  Uid: ( 1001/     fse)   Gid: ( 1001/     fse)
Context: unconfined_u:object_r:user_home_t:s0
Access: 2015-01-27 11:27:27.000000000 +0100
Modify: 2011-02-27 15:15:33.000000000 +0100
Change: 2022-06-04 12:36:12.207680457 +0200
 Birth: -
$ touch -r /etc/hosts test
$ stat test
  File: ‘test’
  Size: 0               Blocks: 0          IO Block: 4096   regular empty file
Device: fd00h/64768d    Inode: 101141036   Links: 1
Access: (0664/-rw-rw-r--)  Uid: ( 1001/     fse)   Gid: ( 1001/     fse)
Context: unconfined_u:object_r:user_home_t:s0
Access: 2022-06-04 10:37:50.880289006 +0200
Modify: 2022-06-04 10:37:48.794362409 +0200
Change: 2022-06-04 12:43:30.705840088 +0200
 Birth: -
$ ls -l
total 0
-rw-rw-r--. 1 fse fse 0 Jun  4 10:37 test

As a curiosity, in all these examples you may notice that the “Change” date updates whenever the metadata has been modified with the current date value.

Update the timestamp of a symlink only

Let’s experiment with the option “-h” of the touch command in order to modify the metadata of the symlink or softlink without affecting the referenced file:

$ date
Sat Jun  4 12:55:05 CEST 2022
$ ln -s test link
$ ls -l
total 0
lrwxrwxrwx. 1 fse fse 4 Jun  4 12:55 link -> test
-rw-rw-r--. 1 fse fse 0 Jun  4 10:37 test
$ stat link
  File: ‘link’ -> ‘test’
  Size: 4               Blocks: 0          IO Block: 4096   symbolic link
Device: fd00h/64768d    Inode: 101141037   Links: 1
Access: (0777/lrwxrwxrwx)  Uid: ( 1001/     fse)   Gid: ( 1001/     fse)
Context: unconfined_u:object_r:user_home_t:s0
Access: 2022-06-04 12:55:11.021278214 +0200
Modify: 2022-06-04 12:55:09.155247740 +0200
Change: 2022-06-04 12:55:09.155247740 +0200
 Birth: -
$ touch -h link
$ stat link
  File: ‘link’ -> ‘test’
  Size: 4               Blocks: 0          IO Block: 4096   symbolic link
Device: fd00h/64768d    Inode: 101141037   Links: 1
Access: (0777/lrwxrwxrwx)  Uid: ( 1001/     fse)   Gid: ( 1001/     fse)
Context: unconfined_u:object_r:user_home_t:s0
Access: 2022-06-04 12:55:39.594744859 +0200
Modify: 2022-06-04 12:55:39.594744859 +0200
Change: 2022-06-04 12:55:39.594744859 +0200
 Birth: -
$ stat test
  File: ‘test’
  Size: 0               Blocks: 0          IO Block: 4096   regular empty file
Device: fd00h/64768d    Inode: 101141036   Links: 1
Access: (0664/-rw-rw-r--)  Uid: ( 1001/     fse)   Gid: ( 1001/     fse)
Context: unconfined_u:object_r:user_home_t:s0
Access: 2022-06-04 10:37:50.880289006 +0200
Modify: 2022-06-04 10:37:48.794362409 +0200
Change: 2022-06-04 12:43:30.705840088 +0200
 Birth: -

Otherwise, if “-h” option is not used then touch command will modify the referenced file and not the symlink:

$ date
Sat Jun  4 12:57:58 CEST 2022
$ stat link
  File: ‘link’ -> ‘test’
  Size: 4               Blocks: 0          IO Block: 4096   symbolic link
Device: fd00h/64768d    Inode: 101141037   Links: 1
Access: (0777/lrwxrwxrwx)  Uid: ( 1001/     fse)   Gid: ( 1001/     fse)
Context: unconfined_u:object_r:user_home_t:s0
Access: 2022-06-04 12:55:45.951848692 +0200
Modify: 2022-06-04 12:55:39.594744859 +0200
Change: 2022-06-04 12:55:39.594744859 +0200
 Birth: -
$ stat test
  File: ‘test’
  Size: 0               Blocks: 0          IO Block: 4096   regular empty file
Device: fd00h/64768d    Inode: 101141036   Links: 1
Access: (0664/-rw-rw-r--)  Uid: ( 1001/     fse)   Gid: ( 1001/     fse)
Context: unconfined_u:object_r:user_home_t:s0
Access: 2022-06-04 10:37:50.880289006 +0200
Modify: 2022-06-04 10:37:48.794362409 +0200
Change: 2022-06-04 12:43:30.705840088 +0200
 Birth: -
$ touch link
$ ls -l
total 0
lrwxrwxrwx. 1 fse fse 4 Jun  4 12:55 link -> test
-rw-rw-r--. 1 fse fse 0 Jun  4 12:58 test
$ stat test
  File: ‘test’
  Size: 0               Blocks: 0          IO Block: 4096   regular empty file
Device: fd00h/64768d    Inode: 101141036   Links: 1
Access: (0664/-rw-rw-r--)  Uid: ( 1001/     fse)   Gid: ( 1001/     fse)
Context: unconfined_u:object_r:user_home_t:s0
Access: 2022-06-04 12:58:25.412444237 +0200
Modify: 2022-06-04 12:58:25.412444237 +0200
Change: 2022-06-04 12:58:25.412444237 +0200
 Birth: -
$ stat link
  File: ‘link’ -> ‘test’
  Size: 4               Blocks: 0          IO Block: 4096   symbolic link
Device: fd00h/64768d    Inode: 101141037   Links: 1
Access: (0777/lrwxrwxrwx)  Uid: ( 1001/     fse)   Gid: ( 1001/     fse)
Context: unconfined_u:object_r:user_home_t:s0
Access: 2022-06-04 12:55:45.951848692 +0200
Modify: 2022-06-04 12:55:39.594744859 +0200
Change: 2022-06-04 12:55:39.594744859 +0200
 Birth: -

Targeting multiple files with touch command

The touch command accepts a basic file parametrisation in order to target multiple files. You can create multiple files with a list of file names:

$ touch a b c d
$ ls -tlr
total 0
-rw-rw-r--. 1 fse fse 0 Jun  4 13:17 a
-rw-rw-r--. 1 fse fse 0 Jun  4 13:17 d
-rw-rw-r--. 1 fse fse 0 Jun  4 13:17 c
-rw-rw-r--. 1 fse fse 0 Jun  4 13:17 b

Or with a fixed prefix and a variable part of the file name by using the brackets “{}”:

$ touch hello_world_{a..d}
$ touch hello_world_{1..5}
$ ls -l
total 0
-rw-rw-r--. 1 fse fse 0 Jun  4 13:21 hello_world_1
-rw-rw-r--. 1 fse fse 0 Jun  4 13:21 hello_world_2
-rw-rw-r--. 1 fse fse 0 Jun  4 13:21 hello_world_3
-rw-rw-r--. 1 fse fse 0 Jun  4 13:21 hello_world_4
-rw-rw-r--. 1 fse fse 0 Jun  4 13:21 hello_world_5
-rw-rw-r--. 1 fse fse 0 Jun  4 13:21 hello_world_a
-rw-rw-r--. 1 fse fse 0 Jun  4 13:21 hello_world_b
-rw-rw-r--. 1 fse fse 0 Jun  4 13:21 hello_world_c
-rw-rw-r--. 1 fse fse 0 Jun  4 13:21 hello_world_d

But if you want to modify the metadata of the files in a target path then, bash options should be used. In the following example it will show how to modify the timestamp of all the files in a folder aided with the find command:

$ date
Sat Jun  4 13:29:00 CEST 2022
$ ls -lR files_num
files_num/:
total 0
drwxrwxr-x. 2 fse fse 90 Jun  4 13:27 files_char
-rw-rw-r--. 1 fse fse  0 Jun  4 13:21 hello_world_1
-rw-rw-r--. 1 fse fse  0 Jun  4 13:21 hello_world_2
-rw-rw-r--. 1 fse fse  0 Jun  4 13:21 hello_world_3
-rw-rw-r--. 1 fse fse  0 Jun  4 13:21 hello_world_4
-rw-rw-r--. 1 fse fse  0 Jun  4 13:21 hello_world_5

files_num/files_char:
total 0
-rw-rw-r--. 1 fse fse 0 Jun  4 13:21 hello_world_a
-rw-rw-r--. 1 fse fse 0 Jun  4 13:21 hello_world_b
-rw-rw-r--. 1 fse fse 0 Jun  4 13:21 hello_world_c
-rw-rw-r--. 1 fse fse 0 Jun  4 13:21 hello_world_d
$ touch -d "2012-12-12 12:12:12.000000000" $(find files_num)
$ ls -lR files_num
files_num/:
total 0
drwxrwxr-x. 2 fse fse 90 Dec 12  2012 files_char
-rw-rw-r--. 1 fse fse  0 Dec 12  2012 hello_world_1
-rw-rw-r--. 1 fse fse  0 Dec 12  2012 hello_world_2
-rw-rw-r--. 1 fse fse  0 Dec 12  2012 hello_world_3
-rw-rw-r--. 1 fse fse  0 Dec 12  2012 hello_world_4
-rw-rw-r--. 1 fse fse  0 Dec 12  2012 hello_world_5

files_num/files_char:
total 0
-rw-rw-r--. 1 fse fse 0 Dec 12  2012 hello_world_a
-rw-rw-r--. 1 fse fse 0 Dec 12  2012 hello_world_b
-rw-rw-r--. 1 fse fse 0 Dec 12  2012 hello_world_c
-rw-rw-r--. 1 fse fse 0 Dec 12  2012 hello_world_d

An idea for touch command usage

You may wonder in which situation would be the touch command be useful but, let’s say that you have a batch script that runs in a scheduled manner that processes files in a target path that were modified after a certain date. However, for any reason some files didn’t process when they should be, and the batch script reference date has been changed to a later one. You can then, leverage touch to set a later date on those pending files so in the next batch script execution, they will be considered again.

Related Posts