Very Computer

by **Brad Hubbar** » Fri, 06 Sep 2002 11:50:42

I would like to fork() in a C++ program I'm writing and then alter an error
string in the parent from the child. How do I need to declare this string
to
be able to access/change it from both the child and the parent.

TIA,
Brad

by **Andreas K?h?r** » Fri, 06 Sep 2002 12:29:24

Submitted by "Brad Hubbard" to comp.unix.programmer:

Quote:> I would like to fork() in a C++ program I'm writing and then alter an error
> string in the parent from the child. How do I need to declare this string
> to
> be able to access/change it from both the child and the parent.

> TIA,
> Brad

You could try to place the string in a shared memory segment (I
don't know how to), but a more resonable way would be to let the
parent change its own string depending on some message sent from
the child.

You could have a set of pipes for passing status codes (i.e.
messages) between child and parent.

If you would consider using POSIX Threads, this kind of thing
gets easier.

--
Andreas K?h?ri
--------------------------------------------------------------
Stable, secure, clean, free: www.netbsd.org

by **M. Gessne** » Sat, 07 Sep 2002 02:23:59

Quote:> Submitted by "Brad Hubbard" to comp.unix.programmer:
>> I would like to fork() in a C++ program I'm writing and then alter an
>> error string in the parent from the child. How do I need to declare
>> this string to
>> be able to access/change it from both the child and the parent.

>> TIA,
>> Brad

> You could try to place the string in a shared memory segment (I
> don't know how to), but a more resonable way would be to let the
> parent change its own string depending on some message sent from
> the child.

> You could have a set of pipes for passing status codes (i.e.
> messages) between child and parent.

> If you would consider using POSIX Threads, this kind of thing
> gets easier.

Sure, shared memory is a pretty straightforward way to do this.

Here's a link to a site that might be helpful to you:

http://www.piratehaven.org/~beej/guide/ipc/

This guy is pretty good. I've found an error or two, which he accepted
without getting defensive.

I'd recommend starting with his page.

by **Brad Hubbar** » Sat, 07 Sep 2002 08:47:09

>> You could try to place the string in a shared memory segment (I
>> don't know how to), but a more resonable way would be to let the
>> parent change its own string depending on some message sent from
>> the child.
> Sure, shared memory is a pretty straightforward way to do this.

> Here's a link to a site that might be helpful to you:

> http://www.piratehaven.org/~beej/guide/ipc/

> This guy is pretty good. I've found an error or two, which he accepted
> without getting defensive.

> I'd recommend starting with his page.

Will do, thanks all.

Brad

Very Computer

Alter variable in parent from child

Alter variable in parent from child

Alter variable in parent from child

Alter variable in parent from child

Alter variable in parent from child