core dump on writing to pipe

[mojozoox]

Could you tell me scenarios in which core's dumped when writing to a
pipe.

write (pipefd,&Struct ,structsize);

on windows too this give a memory "read" violation. Could anyone tell
me why.


thanks in advance.

mojo

[Walter Roberson]

Re: core dump on writing to pipe

In article <1114492407.289 416.279370@g14g 2000cwa.googleg roups.com>,
mojozoox <madireddy@HotP op.com> wrote:[color=blue]
>Could you tell me scenarios in which core's dumped when writing to a
>pipe.[/color]

Pipes are not part of standard C. Can you repeat the
problem with writing to a file opened for binary output?

[color=blue]
>write (pipefd,&Struct ,structsize);[/color]
[color=blue]
>on windows too this give a memory "read" violation. Could anyone tell
>me why.[/color]

structsize perhaps does not match sizeof(Struct) ?

The contents of Struct has perhaps not been initialized and
windows is perhaps detecting this?

pipefd might not be valid?

Struct might not even be the right type -- e.g., it might
really be a pointer to a structure and so you might be
taking the address of a pointer instead of passing
the address of a structure.
--
"[...] it's all part of one's right to be publicly stupid." -- Dave Smey

[SM Ryan]

Re: core dump on writing to pipe

"mojozoox" <madireddy@HotP op.com> wrote:
# Could you tell me scenarios in which core's dumped when writing to a
# pipe.
#
# write (pipefd,&Struct ,structsize);
#
# on windows too this give a memory "read" violation. Could anyone tell

How about adding fprintf(stderr, "%d %p %d\n',pipefd,&S truct,structsiz e)
and see if the output looks rational.

--
SM Ryan http://www.rawbw.com/~wyrmwif/
What kind of convenience store do you run here?

[CBFalconer]

Re: core dump on writing to pipe

SM Ryan wrote:[color=blue]
> "mojozoox" <madireddy@HotP op.com> wrote:
>[color=green]
>> Could you tell me scenarios in which core's dumped when writing
>> to a pipe.
>>
>> write (pipefd,&Struct ,structsize);
>>
>> on windows too this give a memory "read" violation. Could anyone[/color]
>
> How about adding fprintf(stderr, "%d %p %d\n',pipefd,&S truct,structsiz e)
> and see if the output looks rational.[/color]

Apart from the fact that there is no write(...) function in
standard C, and that Windoze is not Posix (neither of which is
on-topic here), your suggested diagnostic is one of the few places
that really need a cast. In this case (void*)&Struct.

Please correct your unconventional quote char. I edited this to
fix it.

--
Chuck F (cbfalconer@yah oo.com) (cbfalconer@wor ldnet.att.net)
Available for consulting/temporary embedded and systems.
<http://cbfalconer.home .att.net> USE worldnet address!

[Keith Thompson]

Re: core dump on writing to pipe

CBFalconer <cbfalconer@yah oo.com> writes:[color=blue]
> SM Ryan wrote:[color=green]
>> "mojozoox" <madireddy@HotP op.com> wrote:
>>[color=darkred]
>>> Could you tell me scenarios in which core's dumped when writing
>>> to a pipe.
>>>
>>> write (pipefd,&Struct ,structsize);
>>>
>>> on windows too this give a memory "read" violation. Could anyone[/color]
>>
>> How about adding fprintf(stderr, "%d %p %d\n',pipefd,&S truct,structsiz e)
>> and see if the output looks rational.[/color]
>
> Apart from the fact that there is no write(...) function in
> standard C, and that Windoze is not Posix (neither of which is
> on-topic here), your suggested diagnostic is one of the few places
> that really need a cast. In this case (void*)&Struct.[/color]

You might need casts for the other arguments as well. I'm guessing
pipefd is probably an int (if so, it doesn't need a cast), but
structsize is likely to be (and probably should be) a size_t.

--
Keith Thompson (The_Other_Keit h) kst-u@mib.org <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <*> <http://users.sdsc.edu/~kst>
We must do something. This is something. Therefore, we must do this.

[mojozoox]

Re: core dump on writing to pipe

is there way to read a core file kindly let me know!

[Walter Roberson]

Re: core dump on writing to pipe

In article <1115043438.597 404.200990@l41g 2000cwc.googleg roups.com>,
mojozoox <madireddy@HotP op.com> wrote:[color=blue]
>is there way to read a core file kindly let me know![/color]

A core file is like any other binary file -- just fopen() it
and fread() it.

Making sense of what you find there is a platform- and version-
specific problem.
--
Beware of bugs in the above code; I have only proved it correct,
not tried it. -- Donald Knuth

[Flash Gordon]

Re: core dump on writing to pipe

mojozoox wrote:[color=blue]
> is there way to read a core file kindly let me know![/color]

Write a C program that opens it in binary more then reads it.

Alternatively, ask in a group dedicated to your system since we don't
deal with implementation specific tools here.
--
Flash Gordon
Living in interesting times.
Although my email address says spam, it is real and I read it.

[SM Ryan]

Re: core dump on writing to pipe

"mojozoox" <madireddy@HotP op.com> wrote:
# is there way to read a core file kindly let me know!

The debugger on your system. Perhaps gdb or sdb or dbg or dbx or mky mus.


--
SM Ryan http://www.rawbw.com/~wyrmwif/
So basically, you just trace.