The previous article has explained how to reduce the size of a file in Linux. This article will explain how to increase the size of a file in Linux.
Problem
How to create a file of a certain size in Linux?
Solution
By default, if you want to create a file, it will use the command:
touch example.txt
And the command above will generate an example.txt file with a size of 0 bytes, as shown in the image below:
However, sometimes there are situations where you have to create a file of a certain size for a purpose, e.g., you have to create a test.txt file with a size of 2 GB, Then there are several methods to generate such files of a certain size:
1. Using the fallocate command
Use the command below to create a test.txt file with a size of 2 GB:
fallocate -l 2048MB test.txt
2. Using the truncate command
Create a test.txt file with a size of 2 GB using the command below:
truncate -s 2048MB test.txt
3. Using the dd command
To produce a test.txt file that is 2 GB in size, run the command below:
dd if=/dev/zero of=test.txt bs=1M count=2048MB
4. Using the head command
Use the command below to generate a test.txt file of size 2 GB:
head --bytes 2048MB /dev/zero > test.txt
5. Using the tail command
Utilize the following command to generate a 2 GB test.txt file:
tail --bytes 2048MB /dev/zero > test.txt
6. Using Perl commands
Below is the command to create a 2 GB test.txt file (the number 2147483648 comes from 2048x1024x1024):
perl -e 'print '0' x 2147483648' > test.txt
7. Using the base64 command
Create a 2 GB test.tx file, followed by (the number 2147483648 comes from 2048x1024x1024):
base64 /dev/urandom | head -c 2147483648 > test.txt
Note
To get quick results when creating a file of a certain size, you can use the truncate or fallocate command.
References
baeldung.com
tutorialspoint.com
ostechnix.com
unix.stackexchange.com
stackoverflow.com
