Network utilities (OMNETUTIL)

The network utilities function library is a set of OmniMark functions that provides functions for:

  • obtaining IP adresses and host names, and
  • manipulating network-ordered binary numbers.

Some network applications send or receive messages that contain numbers in binary form. Computers often represent numbers in binary form as 32-bit values.

32-bit numbers consist of 4 bytes or octets. Different kinds of computers may put these bytes in different orders. When a 32-bit number is transmitted from one computer to another (usually as part of a larger message), both computers must agree on the order of the bytes.

Network ordering is a standard way of ordering the bytes in a 32-bit binary number. It means that the first byte will be the most significant (or highest order) byte of the number, and the last will be the least significant (or lowest order) byte.

(To convert integers to and from the native binary format, see the "b" format command and the binary operator.)

This function library includes the following files:

  • A dynamic link library, such as omnetutl.dll or, which contains the implementation of the OmniMark network utilities API. The library file is dynamically loaded the first time any network utilities function is called.
  • The file omnetutil.xmd, the OmniMark include file that contains the external function declarations.

Usage note

The OMNETUTIL library is packaged as a module. To use OMNETUTIL, you must import the OMETUTIL module into your program using a statement like this:

  import "omnetutil.xmd" prefixed by netutil.

Note that the prefix "netutil.", which is attached to all functions, constants, and opaque data types exported by this library, is set in this statement and can be changed. For readability, we recommend that you always use the standard prefix when importing modules supplied by OmniMark.