Agilent Technologies E4406A VSA manual Using C Programming Over Socket LAN

Programming Examples

Using C Programming Over Socket LAN

Using C Programming Over Socket LAN

This is the C programming example socketio.c. It demonstrates simple socket programming. It is written in C, and compiles in the HP-UX UNIX environment, or the WIN32 environment. It is portable to other UNIX environments with only minor changes.

In UNIX, LAN communication via sockets is very similar to reading or writing a file. The only difference is the openSocket() routine, which uses a few network library routines to create the TCP/IP network connection. Once this connection is created, the standard fread() and fwrite() routines are used for network communication.

In Windows, the routines send() and recv() must be used, since fread() and fwrite() may not work on sockets.

The program reads the analyzer’s host name from the command line, followed by the SCPI command. It then opens a socket to the analyzer, using port 5025, and sends the command. If the command appears to be a query, the program queries the analyzer for a response, and prints the response.

This example program can also be used as a utility to talk to your analyzer from the command prompt on your UNIX workstation or Windows 95 PC, or from within a script.

This program is also available on your documentation CD ROM.

/***************************************************************************

*$Header: lanio.c,v 1.5 96/10/04 20:29:32 roger Exp $

*$Revision: 1.5 $

*$Date: 96/10/04 20:29:32 $

*

*$Contributor: LSID, MID $

* $Description:	Functions to talk to an Agilent E4406A transmitter
*	tester via TCP/IP. Uses command-line arguments.
*
*	A TCP/IP connection to port 5025 is established and
*	the resultant file descriptor is used to "talk" to the
*	instrument using regular socket I/O mechanisms. $
*
*
*

148 Chapter 3