{"id":110394,"date":"2022-08-31T14:00:58","date_gmt":"2022-08-31T08:30:58","guid":{"rendered":"https:\/\/data-flair.training\/blogs\/?p=110394"},"modified":"2022-08-31T14:15:45","modified_gmt":"2022-08-31T08:45:45","slug":"touch-command-in-linux","status":"publish","type":"post","link":"https:\/\/data-flair.training\/blogs\/touch-command-in-linux\/","title":{"rendered":"Touch Command in Linux"},"content":{"rendered":"

In this article, you will learn all there is to the touch command in Linux. We will go through what the touch command is, why it is used, a brief history, different timestamps of a file, the syntax and options of the touch command, and some practical examples of the touch command in the terminal. So sit down, grab your snacks, and read right till the end!<\/p>\n

What is linux touch command?<\/h3>\n

The touch command is a command-line-based utility in Linux-based operating systems that has 2 roles:<\/p>\n

1. Modifying a timestamp<\/p>\n

2. Creating a file.<\/p>\n

The creating files part of the touch command is easy, it can create a file, if and only if the file does not exist. You can even create multiple files using the touch command.<\/p>\n

But the touch command can also change timestamps, but first, what is a timestamp? The timestamp is a way of tracking what happened at what time, it is much like history on a timeline.<\/p>\n

When we create a file or access it, everything gets logged by a timestamp, using the touch command, we can actually change these timestamps! Speaking in technical language, a timestamp is a piece of information associated with a file that identifies an important time in the file\u2019s history.<\/p>\n

History of the touch command in Linux<\/h3>\n

The first appearance of the touch command was in the 7th version of AT&T UNIX. Today, the touch command is available in a range of operating systems, both Linux-based and others like Windows, DOS, macOS, Unix-based, and many more.<\/p>\n

The touch command that comes in the package of Coreutils, was written, designed, and developed by Paul Rubin, Arnold Robbins, Jim Kingdon, David MacKenzie, and Randy Smith.<\/p>\n

Timestamps of Linux files<\/h3>\n

Before we go any further, let us look at the different timestamps a file in the Linux filesystem has. In Linux-based operating systems, a file has 3 timestamps:<\/p>\n

1. atime<\/h4>\n

This timestamp stands for \u2018access time\u2019. This timestamp contains the last time the file was either accessed or opened by commands like \u201ccat\u201d, \u201cvim\u201d, \u201cgrep\u201d, \u201cvi\u201d, etc.<\/p>\n

2. mtime<\/h4>\n

This timestamp stands for modify time\u2019. This timestamp contains the last time the contents of the file were modified.<\/p>\n

3. ctime<\/h4>\n

This timestamp stands for change time\u2019. This timestamp contains the last time the file\u2019s content or attribute was changed. Attributes here mean permissions, location, or ownership.<\/p>\n

If you want to display the status of the file including the timestamps of it use the \u201cstat\u201d command as shown below.<\/p>\n

\"finding<\/a><\/p>\n

Syntax of Linux touch command<\/h3>\n

As we have seen, the touch command has 2 roles (creating files and modifying timestamps), let us take a look at the syntax of the touch command on each case:<\/p>\n

The syntax for creating files using the touch command:<\/p>\n

touch <options> <filename><\/pre>\n
The syntax for creating files consists of 2 fields, one is for options (which we will look into in the next section) and the other is for entering the name of the file you want to create.<\/p>\n
The syntax for modifying timestamps using the touch command:<\/p>\n
touch <options> <timestamp> <filename><\/pre>\n
The syntax for modifying timestamps consists of 3 fields, the first one is for the options, the second for the timestamp you want to modify to, and the third is the filename you want to modify the timestamps of.<\/p>\n
Options used with Linux touch command<\/h3>\n
In both the syntaxes of the touch command, there is a field for options where we can enter a range of available options with which we can specify how touch should function and also how the output should be formatted. Let us look at the options available with the touch command.<\/p>\n
1. -a<\/h4>\n
This option sets only the access time.<\/p>\n
2. -c<\/h4>\n
This option does not create files. You can also write this option as \u201c–no-create\u201d.<\/p>\n
3. -d<\/h4>\n
This option parses the date string and uses it instead of the current time.<\/p>\n
4. -f<\/h4>\n
This option does nothing, nonetheless, it is accepted to provide compatibility with BSD versions of the touch command.<\/p>\n
5. -h<\/h4>\n
This option makes the touch command modify the timestamp of symlink rather than its referenced file if the file you specified is a symbolic link. You can also write this option as \u201c–no-dereference\u201d<\/p>\n
6. -m<\/h4>\n
This option sets only the modification time.<\/p>\n
7. \u2013r<\/h4>\n
This option sets the time of the file you specified to the times of the file reference file you specified instead of the current time.<\/p>\n
8. -t<\/h4>\n
This option uses the numeric timestamp instead of the current time. You can use the format:<\/p>\n
[[CC]YY]MMDDhhmm[.ss]<\/pre>\n
9. –help<\/h4>\n
This option displays the help menu as follows<\/p>\n
\"help-menu<\/a><\/p>\n
10. –version<\/h4>\n
This option displays information about the version of the touch command<\/p>\n
\"version<\/a><\/p>\n
Now that we have laid down the fundamentals, let us look at how to put all of this into action. Let\u2019s start with the simple thing first: creating files using the touch command.<\/p>\n
Creating a single file using the touch command<\/h3>\n
To create a single simply use the following syntax:<\/p>\n
touch <filname><\/pre>\n
\"creating<\/a><\/h3>\n
Creating multiple files using Linux touch command<\/h3>\n
To create multiple files at once using the touch command, let us look at them one by one. The first method is to simply name the files you want to create one after the other as shown: touch <file1> <file2> <file3>.<\/p>\n
\"creating<\/a><\/p>\n
Another method we can use to create multiple files is to use {start .. finish}, use the syntax:<\/p>\n
touch <filename {<start>..<finish>}><\/pre>\n
For example, the command \u201ctouch linux{1..5}\u201d will create the files \u2018linux1\u2019, \u2018linux2\u2019, \u2018linux3\u2019, \u2018linux4\u2019, and \u2018linux5\u2019.<\/p>\n
\"creating<\/a><\/p>\n
That is pretty much it for creating files with the touch command, let us now see how to modify and set timestamp using the touch command.<\/p>\n
Before we look at how to modify timestamps, let us see how to display them, we can make use of the \u201cstat command\u201d, but we can also use the command \u201cls -l\u201d.<\/p>\n
\"printing<\/a><\/p>\n
Setting a specific timestamp with the touch command<\/h3>\n
To set a specific timestamp pair the touch command with the option \u201c-t\u201d followed by the specific timestamp in the following format [[CC]YY]MMDDhhmm[.ss], where<\/p>\n