The VBA FileLen function is used to return the length of a file in bytes. It is used to retrieve the size of any given file, whether it is an Excel workbook, text file, image, or any other type of file. This function can be useful in many scenarios, from checking the size of a file before importing it into a database, to creating a progress bar for a file upload process.
VBA FileLen Function – Purpose, Syntax and Arguments
Purpose:
The main purpose of the FileLen function is to retrieve the size of a file in bytes. It can also be used in conjunction with other VBA functions to perform certain tasks, such as checking the size of a file before copying or transferring it.
Syntax:
The syntax for the FileLen function is as follows:
FileLen (file_path)
Where ‘file_path’ is the full path and name of the file for which the size needs to be retrieved.
Arguments:
- file_path: The full path and name of the file for which the size needs to be retrieved.
Example:
Let’s say we have a file called “test_file.txt” saved on our desktop, and we want to retrieve its size. The code would look something like this:
Dim file_size As Long
file_size = FileLen("C:\Users\Username\Desktop\test_file.txt")
MsgBox "The size of the file is " & file_size & " bytes."
The ‘file_size’ variable is declared as a Long data type, as the FileLen function returns a Long integer value. The message box will display the size of the file in bytes.
Remarks:
- The FileLen function only works with files that are smaller than 2 GB in size. For larger files, the ‘GetAttr’ function can be used to retrieve the size.
- The size returned by the FileLen function is the physical size of the file, not the size on disk. This means that if the file is compressed or encrypted, the size returned will be the compressed or encrypted size, not the actual size on disk.
- If the file does not exist or is inaccessible, an error will occur when using the FileLen function.
Important Notes:
- The FileLen function is not limited to just Excel files, but can be used to retrieve the size of any type of file.
- If you need to perform operations on files larger than 2 GB in size, consider using the APIs provided by the Windows operating system.
In conclusion, the FileLen function is a useful tool for retrieving the size of a file in VBA. It can be used in various scenarios and can assist in performing file operations effectively. It is a simple yet powerful function that is a must-have in any VBA developer’s toolbox.
Understanding VBA FileLen Function with Examples
Basic Usage of FileLen Function
The FileLen Function in VBA (Visual Basic for Applications) is used to determine the size of a file in bytes. This function is important for various purposes, such as checking the size of a file before uploading it or for calculating the appropriate memory allocation for processing large files.
To use the FileLen Function, we need to provide the path and name of the file as a string value within the parentheses. The function then returns the size of the file in bytes as a Long data type.
Here is an example code that demonstrates the basic usage of FileLen Function:
Dim fileSize as Long
fileSize = FileLen("C:\Documents\sample.txt")
'sample.txt' is " & fileSize & " bytes."
MsgBox "File size of
- The first line declares a variable fileSize as a Long data type, which will store the value returned by the FileLen Function.
- The second line uses the FileLen Function to determine the size of the file named “sample.txt” located in the “Documents” folder on the C drive.
- The third line uses the MsgBox function to display the file size along with a message to the user.
Explanation: This example shows how we can use the FileLen Function to retrieve the size of a file and store it in a variable for further processing. As the MsgBox function requires a string value, we have used the ampersand (&) symbol to concatenate the message string with the fileSize variable.
Checking for Non-existent File
One important thing to note while using the FileLen Function is that it only works for files that exist on the system. In case we try to use the function for a non-existent file, it will return an error.
To handle such situations, we can use the Dir function to check if the file exists before using the FileLen Function. The Dir function returns a string value, which contains the file name if it exists, or an empty string if it does not.
Dim file as String file = "C:\Documents\sample.txt" If Dir(file) <> "" Then Dim fileSize as Long fileSize = FileLen(file) 'sample.txt' is " & fileSize & " bytes." MsgBox "File size of End If
- The first line declares a variable file to store the path and name of the file we want to check.
- The If statement checks if the value returned by the Dir function is not an empty string, which means the file exists.
- If the file exists, the FileLen Function is used to determine its size, and the result is displayed using the MsgBox function.
Explanation: This example demonstrates how we can use the Dir function to first check if the file exists before using the FileLen function. This way, we can avoid any errors that may occur due to a non-existent file.
Using FileLen Function to Compare File Sizes
The FileLen Function can also be used for comparing the sizes of two different files. This can be useful in situations where we want to ensure that a file has been downloaded or transferred correctly without any errors.
Dim file1Size as Long, file2Size as Long
file1Size = FileLen("C:\Documents\sample.txt")
file2Size = FileLen("C:\Downloads\sample.txt")
If file1Size = file2Size Then
'sample.txt' has been downloaded/downloaded correctly."
MsgBox "File
Else
'sample.txt' has been downloaded/downloaded incorrectly."
MsgBox "File
End If
- The first line declares two variables, file1Size and file2Size, to store the sizes of two different files.
- The next two lines use the FileLen function to determine the size of each file and assigns it to the respective variable.
- The If statement compares the sizes of both files, and if they are equal, a message is displayed stating that the file has been downloaded correctly, or otherwise, an error has occurred during the download.
Explanation: In this example, we have used the FileLen function to retrieve the sizes of both the original file and the downloaded file. The sizes are then compared using an If statement, and a message is displayed accordingly. This helps in ensuring that the downloaded file is an exact copy of the original file.
Conclusion:
The FileLen Function is a useful tool in VBA as it allows us to retrieve the size of files in bytes, which is essential for various file handling and processing tasks. We can use this function for multiple purposes, such as checking for the existence of a file, comparing file sizes, and allocating appropriate memory for processing large files. By understanding the usage and examples of FileLen Function, we can enhance our VBA programming skills and streamline our file handling processes.
