Segmentation Fault.

[Shivani Joshi]

Hello everyone,

When running a program compiled from C++ source on a Unix Server (Sun OS
5.7) I get a Segmentation Fault and Core Dump.

Can anyone advise as to what I should be looking for in the core-dump to
help me track down the problem.

Thanks!

S.J.

[Danny Kalev]

Most likely, it's a memory related bug. Look for uninitialized pointers,
writing past the end of a buffer, etc.

Danny

Shivani Joshi wrote:
>
> Hello everyone,
>
> When running a program compiled from C++ source on a Unix Server (Sun OS
> 5.7) I get a Segmentation Fault and Core Dump.
>
> Can anyone advise as to what I should be looking for in the core-dump to
> help me track down the problem.
>
> Thanks!
>
> S.J.

[Harish]

First of all try and get the stack trace for the exception and then look for
the specific function which caused the core dump. There you would get an
idea as to whether it was your code or was it the system which actually access
violated. Generally as Danny rightly pointed out, they are due to Uninitialized/Corrputed
pointer values.

rgds,
Harish.



Danny Kalev <dannykk@inter.net.il> wrote:
>Most likely, it's a memory related bug. Look for uninitialized pointers,
>writing past the end of a buffer, etc.
>
>Danny
>
>Shivani Joshi wrote:
>>
>> Hello everyone,
>>
>> When running a program compiled from C++ source on a Unix Server (Sun
OS
>> 5.7) I get a Segmentation Fault and Core Dump.
>>
>> Can anyone advise as to what I should be looking for in the core-dump
to
>> help me track down the problem.
>>
>> Thanks!
>>
>> S.J.

[tns]

One possibility of getting a segmentation fault is with char * declrations.
When you don't initialize it or exceed the limit of '\0' at the length of
the char * then you get a core dump.
If you are using char * then initialize it like
char * xyz = new char(1);
You can always assign string of any length using strcpy() function.

Dangling pointers are a major source for segmentation fault.

If you use gdb then you get the pin-point as to where your program gives
us a problem.

>When running a program compiled from C++ source on a Unix Server (Sun OS
>5.7) I get a Segmentation Fault and Core Dump.
>
>Can anyone advise as to what I should be looking for in the core-dump to
>help me track down the problem.
>

[Shivani Joshi]

Thanks everyone for helping!

[Naveen Philip]

Hello
Shivani
The already existing answers will help you but I can show you one more place
were segmentation fault can occur in unix it is when you try to defference
a null pointer.
eg)char* name = NULL;
/*LATER IN YOUR PROGRAM*/
*name;


"Shivani Joshi" <shivjoshi@hotmail.com> wrote:
>
>Hello everyone,
>
>When running a program compiled from C++ source on a Unix Server (Sun OS
>5.7) I get a Segmentation Fault and Core Dump.
>
>Can anyone advise as to what I should be looking for in the core-dump to
>help me track down the problem.
>
>Thanks!
>
>S.J.