How to Create Files using 'mkfile' Command (with examples)

The mkfile command allows users to create empty files of a specified size, useful in various scenarios such as testing disk performance, simulating file sizes, or reserving space for future use. This command is especially beneficial for Unix-like operating systems where creating a file of an exact size quickly is required. Discover some practical use cases below, complete with motivations and explanations.

Use case 1: Creating an empty file of 15 kilobytes

Code:

mkfile -n 15k path/to/file

Motivation:

Creating an empty file of a specific size is valuable for testing disk quota management or when wanting to ensure that a process or application has a defined amount of disk space available. By using mkfile, you can instantly reserve space without having to fill a file with actual data. This can be handy for system administrators who want to manage space efficiently before deploying an application.

Explanation:

• mkfile: The command used to create files of a specified size.
• -n: An option indicating the size of the file to be created.
• 15k: Specifies the size of the file as 15 kilobytes. The k denotes kilobytes, a multiple used to specify the file size.
• path/to/file: This denotes the directory path and name where the file will be created.

Example output:

Upon executing the command, an empty file named file with a size of 15 kilobytes will be generated at the specified path. The file appears on disk, and if you check its properties, you’ll see it’s exactly 15 kilobytes.

Use case 2: Creating a file of a given size and unit (bytes, KB, MB, GB)

Code:

mkfile -n sizeb|k|m|g path/to/file

Motivation:

The flexibility to define file size using different units like bytes, kilobytes, megabytes, or gigabytes makes the mkfile command highly suited for diverse needs. Developers or testers may use this feature while working with applications that process files of varying sizes to simulate real-world data storage conditions or performance benchmarking.

Explanation:

• size: Denotes the numeric value you wish the file size to be.
• b|k|m|g: Represents the unit of measurement for the file size; b is bytes, k is kilobytes, m is megabytes, and g is gigabytes. Selecting the appropriate unit allows for easy customization of file sizes, depending on the user’s requirements.
• path/to/file: This part of the command indicates where the file will be created on the filesystem.

Example output:

Executing such a command will result in a new empty file at your specified location with the exact size as defined. For instance, using 100m as the size, the file would appear as 100 megabytes on disk with no actual internal data.

Use case 3: Creating two files of 4 megabytes each

Code:

mkfile -n 4m first_filename second_filename

Motivation:

Simultaneously creating multiple files of a defined size can be advantageous when setting up data storage environments for testing or preparing multiple placeholder files. This is particularly beneficial if the files need to represent uniform data structure properties, such as testing file system behavior under load with consistent file sizes.

Explanation:

• 4m: Specifies that each file will be 4 megabytes in size (m for megabytes), ensuring they occupy a suitable amount of space for the intended use.
• first_filename second_filename: These are the names of the two files you are creating. Listing multiple filenames allows mkfile to create more than one file in a single command execution.

Example output:

After running this command, two separate empty files named first_filename and second_filename will reside in your current directory, each with a size of exactly 4 megabytes. This confirms their successful creation with the specified size.

Conclusion:

The mkfile command is a powerful utility for creating files with fixed sizes, invaluable for disk space management, testing, and simulation purposes. Whether you are setting up environment testing, managing disk quotas, or simulating file sizes, the examples provided illustrate how mkfile can be tightly integrated into your workflow to fulfill specific requirements efficiently.