Instead of querying file size, then allocating a buffer, then reading the contents into this buffer -- theio.MappedFile.view method simply maps the requested region of the file and returns a pointer to the mapped region. Mapped files normally give more efficient access on both Windows and Unix (Linux/Mac). If the file is too big, you can sequentially call io.MappedFile.view for sub-regions of the file -- the management of mapped regions happens behind the scene.

In our case, we asked to view a region at file offset 0, file.m_size bytes long -- so the returned pointer can be used to access the whole file.

A more traditional approach would look like:

io.File file;
file.open(fileName, io.FileOpenFlags.ReadOnly);
void* p = new char[file.m_size];
file.read(p, file.m_size);

// work with p

I am now very interested in how this script works. If you don't feel that I abuse your willingness, can you briefly explain how the script works? The operation of file.view is particularly confusing to me as I don't know whether the value of the pointer or the contents of the file is stored in "p".

Could you please share some details about how exactly it doesn't work on your machine (a screenshot maybe)? Re delays -- delays might be necessary if the remote node isn't fast enough to process incoming UDP packets, but the script should send the file line by line regardless of the delays.

You can either:

• double-up the \ characters (i.e., "C:\\TMP\\script\\text.txt")
• use the forward slash character / (i.e., "C:/TMP/script/text.txt")
• use a raw literal that won't apply escape-encoding (i.e., r"C:\TMP\script\text.txt")

Hope this helps!

I set the path to my txt file and run the script. I know it found the file but I get this error:

"Script transmit error:
The filename, directory name, or volume label syntax is incorrect."

File name syntax is in MS-DOS format. "file.open("C:\TMP\script\text.txt", io.FileOpenFlags.ReadOnly);"

Text file looks like this:

8308864495038423916F010201020000628C1DA7628C1DA705F37E4CCDD503B40000000000000000007410020004FFBF0F001Ea199030600000000000000106000000000001A35DF02C8026962347EF0
8308864495038423916F010201020001628C1DA7628C1DA705F37E4CCDD503B40000000000000000007411020004FFBF0F001Ea199030600000000000000106100000000001B333702C8026A62347EF0

...those are just two lines, the file has many more.

What could I have done wrong?

You can achieve what you want with a simple script. Open the file, then iterate over its contents and transmit it line by line:

import "io_base.jncx"
import "io_MappedFile.jnc"

void main() {
	connect(); // ensure the transport is connected

	io.MappedFile file;
	file.open("file-path", io.FileOpenFlags.ReadOnly);
	char const* p = file.view(0, file.m_size);
	char const* end = p + file.m_size;
	
	while (p < end) {
		char const* nl = memchr(p, '\n', end - p);
		if (!nl) {
			if (p < end)
				transmit(p, end - p);
			break;
		}

		transmit(p, nl - p + 1); // include \n
		// transmit(p, nl - p);  // omit \n
		p = nl + 1;
	}
}