1. Reading errno from msvcrt.dll
How do I get the value of errno and _doserrno from msvcrt.dll? I'm using
define_c_var()(using "_errno" and "__doserrno") to get the addresses. I then use
peek4s() to see what their values are. No matter what, I am getting 28075240 and
28071656 decimal respectively. These are invalid error numbers (I've verified
that by using strerror).
I know I am getting the error that I am intentionally causing because I can use
perror to print the error message.
I might not need this, but I would like to rely on more information than just -1
returned from an IO function.
Anyone have experience in this?
2. Re: Reading errno from msvcrt.dll
It's been a while, but isn't "_errno" a function, not a value? I seem to
remember having to figure that out once long ago...
Jonas Temple
http://www.yhti.net/~jktemple
3. Re: Reading errno from msvcrt.dll
Jonas Temple wrote:
>
> It's been a while, but isn't "_errno" a function, not a value? I seem to
> remember
> having to figure that out once long ago...
>
> Jonas Temple
> <a href="http://www.yhti.net/~jktemple">http://www.yhti.net/~jktemple</a>
I've been referring to both the glibc and the msvcrt documentation and they both
say that errno is declared as an external int.
--
"Any programming problem can be solved by adding a level of indirection."
--anonymous
"Any performance problem can be solved by removing a level of indirection."
--M. Haertel
j.
4. Re: Reading errno from msvcrt.dll
- Posted by ags <eu at 531pi.co.nz>
Feb 12, 2006
Jason Gade wrote:
> I've been referring to both the glibc and the msvcrt documentation and they
> both say that errno is declared as an external int.
I don't know if this is relevant:
http://support.microsoft.com/default.aspx?scid=kb;en-us;94248
See section 4, it is about accessing errno in MSVCRT from a another
C Runtime Library not doing what you expect.
I can't see that being the issue though because you are referencing the
variable in MSVCRT presumably.
Gary
5. Re: Reading errno from msvcrt.dll
ags wrote:
>
> Jason Gade wrote:
> > I've been referring to both the glibc and the msvcrt documentation and they
> > both say that errno is declared as an external int.
>
> I don't know if this is relevant:
>
> <a
> href="http://support.microsoft.com/default.aspx?scid=kb">http://support.microsoft.com/default.aspx?scid=kb</a>;en-us;94248
>
> See section 4, it is about accessing errno in MSVCRT from a another
> C Runtime Library not doing what you expect.
>
> I can't see that being the issue though because you are referencing the
> variable in MSVCRT presumably.
>
> Gary
Thanks for the link. It looks like it might be related but I didn't get a clear
solution from it. The thing that gets me is that the perror() function works, but
I would like to get errno so I can pass it back to the user of the library.
I may have to try this on Linux to see what result I get.
--
"Any programming problem can be solved by adding a level of indirection."
--anonymous
"Any performance problem can be solved by removing a level of indirection."
--M. Haertel
j.
