While debugging CORE file with GDB, Why we have to use executable file also along with that?

Question

As far as I know, CORE file contains all the information till Segmentation fault. Then, while debugging core file why we are using executable file(binary) with it.?

Answer 1

You require binary (with debugging symbols included) identical to the one that generated the core, so that you can debug it. Core file does not have debug symbol it is supplied by the binary file (compiled with -g option).

When it starts up, you can use bt (for backtrace) to get a stack trace from the time of the crash. In the backtrace, each function invocation is given a number. You can use frame number (replacing number with the corresponding number in the stack trace) to select a particular stack frame. You can then use list to see code around that function, and info locals to see the local variables. If you done supply the binary then you can not see the code around and local variable information.