Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!uunet!cs.utexas.edu!sdd.hp.com!ucsd!ucbvax!hplabs!hpcc01!hpwrce!ted
From: ted@hpwrce.HP.COM ( Ted Johnson)
Newsgroups: comp.sys.hp
Subject: Re: cartridge tape status
Message-ID: <7870018@hpwrce.HP.COM>
Date: 9 Aug 90 19:51:33 GMT
References: <1990Aug8.185132.13130@cs.uoregon.edu>
Organization: Response Center Lab
Lines: 38

>Is their some kind sole who has figured a way to tell if a tape has been loaded
>in a hp 9145 ct drive without unloading the tape, and would be willing to
>share?  

One ugly way that works (on a s300 & hp-ux 7.0) is to do something
like the following (warning!  This code is from memory, and is untested,
unsupported, etc., etc.)

#include <stdio.h> 
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>

#define SIZE 8192  /*you have to read 8k bytes via the cs80 raw device
                     driver, else it'll fail.*/

main()
{
int fd, nbytes;
char buf[SIZE];

	fd = open("/dev/update.src",O_RDWR | O_NONBLOCK);
	nybtes = read(fd, buf, SIZE);
	if (nbytes == -1) {
		printf("read failed, so no tape in drive\n");
	else {
		printf("tape is in drive and loaded\n");
	}
	close(fd); 

	/*the following open() *rewinds* the tape  */
	fd = open("/dev/update.src",O_RDWR | O_NONBLOCK);

}

-Ted Johnson
 #include <std_disclaimer.h>  ;-)