topic Re: atexit, getting the exit code in Operating System - HP-UX

atexit, getting the exit code

James Myers — Fri, 13 Feb 2004 10:37:40 GMT

Is there a way for an atexit handler to get
the exit code that was in the exit call ?

like exit(5), in my atexit registered
function, can I determine it was 5 ?

I am using the atexit to register an exit
handler for a C program, using the aCC compiler, hpux 11.0

Re: atexit, getting the exit code

Jeff Schussele — Fri, 13 Feb 2004 10:40:34 GMT

Hi James,

echo $?

will give you exit code.

HTH,
Jeff

Re: atexit, getting the exit code

A. Clay Stephenson — Fri, 13 Feb 2004 10:52:55 GMT

Because the handlers pushed by atexit expect no arguments there is no direct, portable method to accomplish this. However, you should be able to
create a wrapper function for exit(), e.g myexit() that first takes the argument and assigns it to a global variable which your handlers could then access.

e.g.

int Exit_Status = 1;

/* sample silly function to feed atexit() */
void myexithandler()
{
(void) fprintf(stderr,"Exit Status = %d\n",Exit_Status);
(void) fflush(stderr);
return;
} /* myexithandler */

Now instead of using exit() in your code, use myexit();

void myexit(int status)
{
Exit_Status = status;
exit(status);
/* NOTREACHED */
return;
} /* myexit */

Re: atexit, getting the exit code

ranganath ramachandra — Mon, 16 Feb 2004 00:52:56 GMT

(there seems to be no nice API for this)

defining something with a name other than exit will not let you catch exit's that are not called form your code.

you can define your own 'void exit(int status) which will override exit() of libc. put your atexit handler code in this exit() routine and at the end a call to '_exit(status)'. the difference between calling exit() and _exit() is in the exit() man page.

if you run into problems because of other (crt0/dld.sl) atexit handlers not being called, you may need to implement atexit() as well ...