procexec/exit_handlers.c

This is procexec/exit_handlers.c (Listing 25-1, page 536), an example from the book, The Linux Programming Interface.

The source code file is copyright 2022, Michael Kerrisk, and is licensed under the GNU General Public License, version 3.

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  Cover of The Linux Programming Interface

Function list (Bold in this list means a function is not static)

/* exit_handlers.c

   Demonstrate the use of atexit(3) and on_exit(3), which can be used to
   register functions (commonly known as "exit handlers") to be called at
   normal process exit. (These functions are not called if the process does
   an _exit(2) or if it is terminated by a signal.)
*/
#define _BSD_SOURCE     /* Get on_exit() declaration from <stdlib.h> */
#include <stdlib.h>
#include "tlpi_hdr.h"

#ifdef __linux__        /* Few UNIX implementations have on_exit() */
#define HAVE_ON_EXIT
#endif
static void
atexitFunc1(void)
{
    printf("atexit function 1 called\n");
}
static void
atexitFunc2(void)
{
    printf("atexit function 2 called\n");
}
#ifdef HAVE_ON_EXIT
static void
onexitFunc(int exitStatus, void *arg)
{
    printf("on_exit function called: status=%d, arg=%ld\n",
                exitStatus, (long) arg);
}
#endif
int
main(int argc, char *argv[])
{
#ifdef HAVE_ON_EXIT
    if (on_exit(onexitFunc, (void *) 10) != 0)
        fatal("on_exit 1");
#endif
    if (atexit(atexitFunc1) != 0)
        fatal("atexit 1");
    if (atexit(atexitFunc2) != 0)
        fatal("atexit 2");
#ifdef HAVE_ON_EXIT
    if (on_exit(onexitFunc, (void *) 20) != 0)
        fatal("on_exit 2");
#endif

    exit(2);
}

 

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