Re: Newbie lost with a segmentation fault

[Chris Majewski <majewski at cascade dot cs dot ubc dot ca>]

That's a good book though some of the exercises are tricky! 
The secret to finding seg faults and other bugs is to use gdb, the GNU
debugger. If you're already using a good editor like Emacs you can run
this inside your editor (M-x gdb). Gdb expects the name of the
executable (eg a.out) as its argument. Once inside gdb you can type 
help
or you can read the Info file on gdb (M-x info RET gdb). 
(Usually seg faults come from pointer bugs like this:
int *x = 0;
int y = *x;)

-chris


John Soltow <jasoltow@erols.com> wrote:
>     I'm in the process of teaching myself C through "The C Programming
> Language" (Brian Kernighan & Dennis Ritchie) and
> am having problem with a piece of code.  The code compiles ok (using GCC
> under Linux), but segmentation faults when run.

>     I'm not as concerned about what is wrong with the code (for the
> purpose of this message) as I am with how to go about finding the
> problem when I get a seg fault/core dump.  In this case, everything in
> the code looks fine.  I know from reading elsewhere in Usenet that the
> core file can be used as a troubleshooting aid in finding the problem in
> the code.  Can someone point me to the documentation that explains how
> to do that?

>     If it matters, I'm running gcc version egcs-2.91.66 19990314/Linux
> (egcs-1.1.2 release)

>     Thanks,
>     John Soltow