Linux make file empty

How to create an empty file from command line

But if newfile already exists and isn’t empty, then touch newfile will leave you with a nonempty file. Maybe not what you wanted.

@CamilleGoudeseune I think If newfile already exists, touch command will just update the timestamp of file (which is what command exactly for) without editing the contents of file.

Will also create an empty file. If the file does already exist, it will be truncated (emptied). To keep the file contents, use >> for appending as in:

Even if the file exists, the contents will be untouched.

Edit: If you don’t have any content to type, this one is faster:

user@host$ :> newfile user@host$ :>> new_or_existing_file 

Note. : is the command here. It is not part of the prompt.

If you want to create as root

To not truncate existing file:

I don’t think so. Any shell which allows redirection of output stream to a file should support this. This will truncate the file if it already exists. touch is safe to use if you don’t want to empty it.

the exact way there is also another way

The difference is file1.ext will be zero bytes and file2.ext would be one byte. You can check this by

No, ‘echo «» >’ does not create an empty file, it creates a file containing a newline. If you for some reason want to use echo to create an empty file you will have to use ‘echo -n «» >’, or simply ‘echo -n >’

Using vim editor you can also create an empty file.

creates an empty file, if your version of echo supports the -n switch.

In general, creating any regular 1 file on Linux involves open(2) , openat(2) , and creat(2) system calls (and specifically with O_CREAT flags). That means if you call any command-line utility that does these system calls, you can create a new empty file.

Most commonly new filename is created with something like this:

• touch /tmp/new_file
• : > /tmp/new_file
• true > /tmp/new_file
• > /tmp/new_file ( bash shell only )

touch is a standalone utility. Its original purpose is to update the access and modification time of a file, however if the file does not exist — it will be created. Note also that a filename — is treated specially, so if you do want to create a file that is named literally — , you’ll have to enclose that into single or double quotes.

By contrast, > is a shell redirection operator for stdout stream. The > operator specifically calls the openat() system call with O_WRONLY|O_CREAT|O_TRUNC flags. That means, if the filename does not exist — it will be created, and if it does — the data will be truncated (and therefore gone, so > should be used with care). In most shells nowadays true or : is a built-in , so doing : > /tmp/new_file is going to be more efficient, although marginally compared to touch /tmp/new_file .

But of course it does not stop there. As mentioned, anything that can perform open() , openat() and, create() syscalls will create a file. Hence, we can do:

• true|dd of=/tmp/newfile
• truncate —size 0 /tmp/new_filename.txt
• cp /dev/null /tmp/null_file
• true|tee /tmp/some_other_file
• mktemp or tempfile ( for creating temporary files that do not need to exist between reboots !)

Of course, all the above mentioned utilities do not exclusively create files. But they perform the necessary syscall and that allows us to adapt the commands.

Of course, at the level of programming or scripting we may want to create a file as well, especially for efficiency purposes (because calling external commands such as touch from a Perl script or Python will require additional resources).

$ python -c 'import sys,os;f=sys.argv[1];os.utime(f,None) if os.path.exists(f) else open(f,"a").close' myfile.txt 

We can make it shorter with this:

$ python -c 'import sys,os;f=sys.argv[1];'$'\n''with open(f,"a"): os.utime(f,None)' mysecondfile.txt 

$ perl -e 'open(my $fh,">","/tmp/perlfile")' 

1 Other types of files such as hard/soft links,character or block special devices, directory,named pipes, or sockets require entirely different syscalls.

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4 Ways to Create a Text File in Linux Terminal

In this Linux beginner series, you’ll learn various methods to create a file in Linux terminal.

In this Linux beginner series, you’ll learn various methods to create a text file in Linux terminal.

If you have used the desktop oriented operating system such as Windows, creating file is a piece of cake. You right click in the file explorer and you would find the option of creating new file.

Things won’t look the same when you are in a command line environment. There is no right click option here. So how do you create a file in Linux then? Let me show you that.

Create file in Linux command line

There are various ways of creating a new file in Linux terminal. I’ll show you the commands one by one. I am using Ubuntu here but creating files in Ubuntu terminal is the same as any other Linux distribution.

1. Create an empty file using touch command

One of the biggest usages of the touch command in Linux is to create a new empty file. The syntax is super simple.

If the file doesn’t exist already, it will create a new empty file. If a file with the same name exists already, it will update the timestamps of the file.

2. Create files using cat command

Another popular way of creating new file is by using the cat command in Linux. The cat command is mostly used for viewing the content of a file but you can use it to create new file as well.

You can write some new text at this time if you want but that’s not necessary. To save and exit, use Ctrl+D terminal shortcut.

If the file with that name already exists and you write new text in it using the cat command, the new lines will be appended at the end of the file.

3. Create new file using echo command

The main use of the echo command is to simply repeat (echo) what you type on the screen. But if you use the redirection with echo, you can create a new file.

To create a new file using echo you can use something like this:

echo "This is a sample text" > filename.txt

The newly created filename.txt file will have the following text: This is a sample text. You can view the file in Linux using cat or other viewing commands.

You are not obliged to put a sample text with echo. You can create an (almost) empty file using the echo command like this:

This will create a new file with just one empty line. You can check the number of lines with wc command.

4. Create a new file using a text editor like Nano or Vim

The last method in this series is the use of a text editor. A terminal-based text editor such as Emacs, Vim or Nano can surely be used for creating a new file in Linux.

Before you use these text editors, you should make sure that you know the basics such as saving an existing from the editor. Unlike the GUI tools, using Ctrl+S in the terminal won’t save the file. It could, in fact, send your terminal into a seemingly frozen state from which you recover using Ctrl+Q.

Let’s say you are going to use Vim editor. Make sure that you are aware of the basic vim commands, and then open a new file with it like this:

What’s your favorite command?

So, I just shared 4 different ways of creating a file in Linux. Personally, I prefer using touch for creating empty file and Vim if I have to edit the file. On a related note, you may want to learn about the file command in Linux that is helpful in determining the actual type of the file.

Which command do you prefer here? Please share your views in the comment section below.

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How do I create a new empty file in a bash script?

I’m running some third-party Perl script written such that it requires an output file for the output flag, -o . Unfortunately, the script appears to require an actual file, that is, users must create an empty file filename.txt with 0 bytes and then input this empty file on the script command line

perl script1.pl -o filename.txt 

Question: How would I create an empty file within a bash script? If one simply tries perl script1.pl -o filename.txt , the script gives an error that the file doesn’t exist.

5 Answers 5

Use touch command. touch filename.txt .

Actually I tried touch and «echo -n > file» inside my bash script but I get an error when I execute the script: «No such file or directory» on that line. Can someone help please?

Use the null command ( : ) redirect ( > filename ) trick ( :> ), as this will truncate to zero or create the named file.

$ echo foo > filea $ :> filea $ wc -c filea 0 filea $ rm filea $ :> filea $ wc -c filea 0 filea 

(This will fail if the shell sets a NOCLOBBER option.)

Just > filename.txt would do, no need for the : . Or >> filename.txt if we don’t want to trash it if it does happen to exist.

@ilkkachu although the question does specify Bash, using : does make the script more likely to accomplish its task with other shells e.g. Zsh.

You could always use perl, too.

$ stat filename.txt stat: cannot stat 'filename.txt': No such file or directory $ perl -e 'open($fh,">","filename.txt") or die $!;close($fh)' $ stat filename.txt File: 'filename.txt' Size: 0 Blocks: 0 IO Block: 4096 regular empty file Device: 801h/2049d Inode: 280728 Links: 1 Access: (0664/-rw-rw-r--) Uid: ( 1000/ xieerqi) Gid: ( 1000/ xieerqi) Access: 2017-02-08 13:51:01.479121995 -0700 Modify: 2017-02-08 13:51:01.479121995 -0700 Change: 2017-02-08 13:51:01.479121995 -0700 Birth: - 

dd can be used to create an empty file as follows:

dd if=/dev/null of=filename.txt count=0 

One case where dd is more useful than the other approaches is creating an EFI variable (PK) through the efivars filesystem ( /sys/firmware/efi/efivars ).

One some platforms and Linux distributions, the file is created with the » immutible » attribute set (shows up as the » i » flag with » lasattr «). So, any subsequent operations on the file fail.

For example, touch not only creates the file, but sets the time stamp on the file. Similarly, piping to the file with > not only creates the file, but performs additional operations that fail. The dd command does not appear to fail the same way.

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