From: "Juan Manuel Guerrero" <ST001906 AT HRZ1 DOT HRZ DOT TU-Darmstadt DOT De>
Organization: Darmstadt University of Technology
To: Igor Bujna <igor DOT bujna AT maxi-tip DOT cz>
Date: Tue, 21 Aug 2001 10:26:23 +0200
Subject: Re: Problem with GDBM-1.8.0
CC: djgpp AT delorie DOT com
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On Sun, 19 Aug 2001, Igor Bujna wrote:
> Hi,
> i have problem with function gdbm_open in gdbm-1.8.0.
> When i use  GDBM_WRCREAT or GDBM_NEWDB flag and then i 
> want put some data to file i get message "gdbm fatal: read error:".
> This is my test.c file:
[snip]
> I think problem somewhere when gdbm creating file,because
> when i compile and run this file (test.c) on my linux is everything OK.
> File "test.dbf" look on linux OK.But when I run under DJGPP file 
> "test.dbf" look damage.This problem is same when i try run 
> testgdbm program, which is in yours gdbm-1.8.0-source(i try on 
> yours binary or source).

It is not possible to me to reproduce the error message you described.
Netherless the port is broken. I have tried your test program
on DOS 6.22 and Win95 with the actual port (timestamp:2001-05-25)
and it always aborts with the following traceback:

D:\test>a
Exiting due to signal SIGSEGV
Page fault at eip=000033b8, error=0004
eax=00000000 ebx=02000000 ecx=0000102e edx=00000000 esi=06000000 edi=00097e84
ebp=000976b0 esp=000976a4 program=D:\TEST\A.EXE
cs: sel=00af  base=82960000  limit=ffed0fff
ds: sel=00b7  base=82960000  limit=ffed0fff
es: sel=00b7  base=82960000  limit=ffed0fff
fs: sel=0087  base=000081a0  limit=0000ffff
gs: sel=00c7  base=00000000  limit=0010ffff
ss: sel=00b7  base=82960000  limit=ffed0fff
App stack: [000977b0..000177b0]  Exceptn stack: [00017704..000157c4]
 
Call frame traceback EIPs:
  0x000033b8 _get_elem+84, line 316 of falloc.c
  0x00002f31 __gdbm_alloc+33, line 70 of falloc.c
  0x00001f23 _gdbm_store+235, line 124 of gdbmstore.c
  0x0000168c _main+228, line 15 of a.c
  0x00004cc2 ___crt1_startup+178
 

The reason for this failure is that all files are *opened*
and/or *created* in dos text mode instead of binary mode.
This has the concequence that pointers and indices are initialized
with wrong data making the hole library fail. I have fixed this
and I will upload a corrected port ASAP. The patch below based on
the actual DJGPP port will fix the dificulty and it contains a small
test program to read a GDBM file created with your test program.
Please note that you must recompile the sources to get a working library.
Thank you for the bug report and excuse the inconveniences caused.

Regards,
Guerrero, Juan Manuel


diff -acprNC3 gdbm-1.8-0.orig/_test.c gdbm-1.8-0/_test.c
*** gdbm-1.8-0.orig/_test.c	Thu Jan  1 00:00:00 1970
--- gdbm-1.8-0/_test.c	Tue Aug 21 04:20:54 2001
***************
*** 0 ****
--- 1,39 ----
+ #include <stdio.h>
+ #include <stdlib.h>
+ #include <string.h>
+ #include <gdbm.h>
+ 
+ main (int argc, char *argv[])
+ {
+   GDBM_FILE dbf;
+   datum key, data;
+ 
+   if (argc < 3)
+   {
+     fprintf (stderr, "Usage: %s <GDBM file> <KEY>\n\n", argv[0]);
+     exit (1);
+   }
+ 
+   dbf = gdbm_open (argv[1], 512, GDBM_READER, 0664, NULL);
+   if (!dbf)
+   {
+     fprintf (stderr, "File %s either doesn't exist or is not a gdbm file.\n", argv[1]);
+     exit (2);
+   }
+ 
+ 
+   key.dptr  = argv[2];
+   key.dsize = strlen (argv[2]) + 1;
+ 
+   data = gdbm_fetch (dbf, key);
+ 
+   if (data.dsize > 0)
+   {
+     printf ("Key: %s Data: %s\n", key.dptr, data.dptr);
+     free (data.dptr);
+   }
+   else
+     printf ("Key %s not found.\n", argv[2]);
+ 
+   gdbm_close (dbf);
+ }
diff -acprNC3 gdbm-1.8-0.orig/gdbmopen.c gdbm-1.8-0/gdbmopen.c
*** gdbm-1.8-0.orig/gdbmopen.c	Wed May 19 00:16:06 1999
--- gdbm-1.8-0/gdbmopen.c	Tue Aug 21 04:08:46 2001
*************** gdbm_open (file, block_size, flags, mode
*** 126,146 ****
    switch (flags & GDBM_OPENMASK)
      {
        case GDBM_READER:
! 	dbf->desc = open (dbf->name, O_RDONLY, 0);
  	break;
  
        case GDBM_OPENMASK:
! 	dbf->desc = open (dbf->name, O_RDWR, 0);
  	break;
  
        case GDBM_NEWDB:
! 	dbf->desc = open (dbf->name, O_RDWR|O_CREAT, mode);
  	flags = GDBM_WRITER;
  	need_trunc = TRUE;
  	break;
  
        default:
! 	dbf->desc = open (dbf->name, O_RDWR|O_CREAT, mode);
  	flags = GDBM_WRITER;
  	break;
  
--- 126,146 ----
    switch (flags & GDBM_OPENMASK)
      {
        case GDBM_READER:
! 	dbf->desc = open (dbf->name, O_RDONLY|O_BINARY, 0);
  	break;
  
        case GDBM_OPENMASK:
! 	dbf->desc = open (dbf->name, O_RDWR|O_BINARY, 0);
  	break;
  
        case GDBM_NEWDB:
! 	dbf->desc = open (dbf->name, O_RDWR|O_CREAT|O_BINARY, mode);
  	flags = GDBM_WRITER;
  	need_trunc = TRUE;
  	break;
  
        default:
! 	dbf->desc = open (dbf->name, O_RDWR|O_CREAT|O_BINARY, mode);
  	flags = GDBM_WRITER;
  	break;