Return value of program being debugged

Return value of program being debugged

[Grzegorz Cieslewski]

Hi,

I have encountered an interesting problem.
Upon executing the program:
int main()
{
        return(-1);
}

in gdb I get the following output

(gdb) r
Starting program: /tmp/test

Program exited with code 0377.
(gdb) q

Could someone tell me how is "-1" mapped to "0377"?

Greg
-- 
=====================================================
Grzegorz Cieslewski
Research Assistant
High-performance Computing & Simulation (HCS) Research Laboratory
University of Florida, Dept. of Electrical and Computer Engineering
330 Benton Hall, Gainesville, FL, 32611-6200
Phone: (352) 392-9041
Email: cieslewski@hcs.ufl.edu
Web: www.hcs.ufl.edu
=====================================================

Re: Return value of program being debugged

[Daniel Jacobowitz]

On Sat, Dec 15, 2007 at 09:33:02AM -0500, Grzegorz Cieslewski wrote:
> (gdb) r
> Starting program: /tmp/test
> 
> Program exited with code 0377.
> (gdb) q
> 
> Could someone tell me how is "-1" mapped to "0377"?

(gdb) p/x 0377
$1 = 0xff

Take a look at the manual page for waitpid, and the definitions of the
various waitstatus macros, to see how Unix systems represent exit
codes.

-- 
Daniel Jacobowitz
CodeSourcery