This C function, `InsertShort`, writes a 2-byte (16-bit) unsigned short...

This C function, InsertShort, writes a 2-byte (16-bit) unsigned short integer to a file in big-endian byte order. Here's a breakdown of what it does:

1. Parameters:

   • FILE* f: A file pointer representing an open file to which the data will be written.
   • unsigned short data: The 16-bit unsigned integer that will be written to the file.

2. Local Buffer (buf[2]):

   • A 2-byte array (buf) is created to store the individual bytes of the data variable.
   • buf[1] is assigned the least significant byte (LSB) of data using data & 0xFF.
   • buf[0] is assigned the most significant byte (MSB) of data using (data >> 8) & 0xFF.

3. Write to File:

   • fwrite is called to write the 2-byte buffer (buf) to the file f.
   • It writes 2 bytes (1 item of size 2) to the file.

4. Return Value:

   • The function returns the number of bytes successfully written (expected to be 2).

Summary:

• This function converts a 16-bit unsigned short into big-endian format and writes it to the file pointed to by f.
• It returns the number of bytes actually written to the file.

Big-endian means the most significant byte (MSB) comes first, followed by the least significant byte (LSB), which is evident from how buf is populated. If fwrite succeeds, the expected return value is 2.