Path: utzoo!yunexus!maccs!innovus!martin
From: martin@innovus.UUCP (Martin Renters)
Newsgroups: comp.sys.hp
Subject: Strange behaviour on HP9000/825
Keywords: errno 25 cc errors
Message-ID: <227@innovus.UUCP>
Date: 25 Jul 89 21:37:45 GMT
Article-I.D.: innovus.227
Organization: Innovus Inc, Hamilton, Ont. Canada
Lines: 43


We just found some rather strange behaviour on our 9000/825 running
HP-UX 3.0.  Seems we get an errno 25 (not a typewriter) on the first
I/O we do on any newly opened file, although the I/O is actually carried
out. Any subsequent I/Os work fine, without error. Both HFS and NFS
filesystems seem to have this problem.

Here's a test program (a.c) that illustrates this problem:

#include <stdio.h>
#include <errno.h>
extern int errno;

main()
{
	FILE *fp; char buffer[80];
	buffer[0]='\0';

	if ((fp=fopen("a.c","r")) == NULL)
	{
		printf("File fails to open\n");
		exit(2);
	}
	printf("File opens, errno=%d, fp=%d\n",errno,fp);
	fgets(buffer,64,fp);
	printf("File read, errno=%d, fp=%d, buffer=%s",errno,fp,buffer);
	clearerr(fp); errno=0;
	fgets(buffer,64,fp);
	printf("File read2, errno=%d, fp=%d, buffer=%s",errno,fp,buffer);
}

When compiled with 'cc a.c' and executed the following output results:

File opens, errno=0, fp=1073742056
File read, errno=25, fp=1073742056, buffer=#include <stdio.h>
File read2, errno=0, fp=1073742056, buffer=#include <errno.h>

Anybody care to comment about why this is happening?


Martin Renters				martin@innovus
Technical Analyst			..utgpu!maccs!innovus!martin
Innovus Inc.