FAQ Search Today's Posts Mark Forums Read
» Video Reviews

» Linux Archive

Linux-archive is a website aiming to archive linux email lists and to make them easily accessible for linux users/developers.


» Sponsor

» Partners

» Sponsor

Go Back   Linux Archive > Gentoo > Gentoo User

 
 
LinkBack Thread Tools
 
Old 08-09-2010, 07:33 PM
"Kevin O'Gorman"
 
Default GDBM incompatibility woes; any experts out there?

Around 2002, I started working on a project that involved a few simple database tables, and I wanted it
simple, so I used python and the gdbm module.* Since then, all has been well.* Now I find that not only
do the gdbm modules of python and perl reject my files, but so does a C program that uses the distributed

libgdbm.

Okay, so you think I broke my files somehow.* I was afraid that was true, so I used the gdbm source
I had in distfiles, configured it with default setup but did not install it.* Instead I compiled it with my

C test program, and set out to find the problem in the data, more or less expecting
to spend a long time in the debugger.* But lo and behold, it worked just fine.* Now I'm suspecting that
the ebuild does something (Large File support?) to the GDBM that it didn't used to do.


I did not know when I started how much configuration information I was going to need, and so there's
a configuation database.* As it happens, I never put more than one record in it, so it's perfect for
simple testing.* The database is called dbhex.control, and the single record key is "control".* I've

attached it.

I used this Makefile, with no targets or rules, just to get the flags I want: I have my testfile 'testgdbm.c' in
the same directory with the makefile, and a gdbm-1.8.3 directory.

I make testgdbm, run "testgdbm dbhex.control" and get exactly what I should.* If I link against the

Gentoo gdbm distribution, I get error 22 "invalid argument".* Not knowing much about ebuilds, I'm not sure
how to tell what has changed.

Can anybody help me with:
* 1) why it fails now with Gentoo tools.

* 2) the best way to get it working again, preferably with both python and C.* I expect there's either
***** a compatibility flag, or I may need to do a file conversion.* Overall, my databases run to about
***** 3 gigabytes, so it's doable either way.


Thanks in advance for any help.

# Makefile for tests
CC=gcc
CFLAGS=-Wall -g -m32 -ansi
LDFLAGS=-m32 gdbm-1.8.3/global.o gdbm-1.8.3/gdbmopen.o gdbm-1.8.3/gdbmerrno.o gdbm-1.8.3/gdbmclose.o gdbm-1.8.3/update.o gdbm-1.8.3/falloc.o gdbm-1.8.3/bucket.o gdbm-1.8.3/gdbmfetch.o gdbm-1.8.3/findkey.o gdbm-1.8.3/version.o gdbm-1.8.3/gdbmseq.o gdbm-1.8.3/hash.o


My test file:

/**
** @file
**
** Program to test minimal functionality of the gdbm library on a known gdbm file.
**
** Last Modified: Mon Aug* 9 12:01:32 PDT 2010</pre>

** @author Kevin O'Gorman
**/

#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <gdbm.h>
#include <string.h>
#include <errno.h>

void

fatal(void) {
* fprintf(stderr, "Fatal function called
");
* fprintf(stderr, "Errno is %d
", errno);
* exit(EXIT_FAILURE);
}

/** The main thing.
** @param argc the number of tokens on the input line.

** @param argv an array of tokens.
** @return 0 on success, 1-255 on failure
**/
int
main(int argc, char *argv[])
{
* datum key;
* datum value;
* datum nextkey;
* char longbucket[4096];

* printf("Running with GDBM: %s
", gdbm_version);

* if (argc !=2) {
*** fprintf(stderr, "Usage:
** %s filename
", argv[0]);
*** exit(EXIT_FAILURE);
* }

* errno = 0;
* GDBM_FILE control = gdbm_open(argv[1], 1024, GDBM_READER, 0666, fatal);

* if (control == NULL) {
*** perror("gdbm");
*** fprintf(stderr, "Open returned NULL
");
*** fprintf(stderr, "Errno is %d
", errno);
*** exit(EXIT_FAILURE);
* }
* printf("is open
");

*
* key = gdbm_firstkey(control);
* while (key.dptr) {
*** memcpy(longbucket, key.dptr, key.dsize);
*** longbucket[key.dsize] = '';
*** printf("Key: %s", longbucket);
*** value = gdbm_fetch(control, key);

*** memcpy(longbucket, value.dptr, value.dsize);
*** longbucket[value.dsize] = '';
*** printf(", val: "%s"
", longbucket);
*** free(value.dptr);
*** nextkey = gdbm_nextkey(control, key);

*** free(key.dptr);
*** key = nextkey;
* }

* gdbm_close(control);
* printf("That's all, folks...
");
*
* return EXIT_SUCCESS;
}

/* vim: set et ai sts=2 sw=2: */


--
Kevin O'Gorman, PhD
 
Old 08-09-2010, 09:49 PM
walt
 
Default GDBM incompatibility woes; any experts out there?

On 08/09/2010 12:33 PM, Kevin O'Gorman wrote:

> ...

Now I find that not only
do the gdbm modules of python and perl reject my files, but so does a C program that uses the distributed
libgdbm.


You didn't say how long ago the problem started, but looking at the
files in sys-libs/gdbm I see nothing newer than March 20. Is your
problem newer than March 20?

Have you tried running your test program with strace?
 

Thread Tools




All times are GMT. The time now is 11:07 AM.

VBulletin, Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Relevant URLs by vBSEO ©2007, Crawlability, Inc.
Copyright 2007 - 2008, www.linux-archive.org