From: kagel AT quasar DOT bloomberg DOT com
Date: Thu, 30 Jan 1997 11:26:06 -0500
Message-Id: <9701301626.AA16799@quasar.bloomberg.com >
To: jrubin AT bix DOT com
Cc: djgpp AT delorie DOT com
In-Reply-To: <5co52q$hg0@news2.delphi.com> (jrubin@bix.com)
Subject: Re: Why can't GDB set a variable?
Reply-To: kagel AT dg1 DOT bloomberg DOT com

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   From: jrubin AT bix DOT com (jrubin)
   Newsgroups: comp.os.msdos.djgpp
   Date: 29 Jan 1997 18:31:54 GMT
   Organization: BIX
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   GDB claims to be changing the value of the variable 'x',
   but the program doesn't seem to notice. When GDB exits,
   it reports failure to close the image file.


   File test.c:
   ------------
   #include <stdio.h>

   int x = 1;

   int main(void)
   {
     printf("test.c: x = %d\n",x);
     return 0;
   }

   --------------
   gcc -g test.c
   gdb a.out
   (gdb) p x
   $1 = 1
   (gdb) set var x = 100
   (gdb) p x
   $2 = 100
   (gdb) r

No, no.  When you entered the run (r) command GDB reloaded the executable from disk 
and wiped out your change to 'x'.  Try this:


gdb a.out
(gdb) b main
Breakpoint 1 at 0x101a88
(gdb) r
Starting program: c:/jsc/runtime/a.out
(gdb) p x
$1 = 1
(gdb) set var x = 100
(gdb) p x
$2 = 100
(gdb) step
(gdb) p x
$2 = 100
(gdb) cont
test.c: x = 100
(gdb) q

-- 
Art S. Kagel, kagel AT quasar DOT bloomberg DOT com

A proverb is no proverb to you 'till life has illustrated it.  -- John Keats