User login |
atexit (3)
ATEXIT(3) Linux Programmer's Manual ATEXIT(3)
NAME
atexit - register a function to be called at normal process termination
SYNOPSIS
#include <stdlib.h>
int atexit(void (*function)(void));
DESCRIPTION
The atexit() function registers the given function to be called at nor-
mal process termination, either via exit(3) or via return from the pro-
gram's main(). Functions so registered are called in the reverse order
of their registration; no arguments are passed.
POSIX.1-2001 requires that an implementation allow at least ATEXIT_MAX
(32) such functions to be registered. The actual limit supported by an
implementation can be obtained using sysconf(3).
When a child process is created via fork(2), it inherits copies of its
parent's registrations. Upon a successful call to one of the exec(3)
functions, all registrations are removed.
RETURN VALUE
The atexit() function returns the value 0 if successful; otherwise it
returns a non-zero value.
CONFORMING TO
SVr4, 4.3BSD, C89, C99, POSIX.1-2001.
NOTES
Functions registered using atexit() (and on_exit(3)) are not called if
a process terminates abnormally because of the delivery of a signal.
Linux Notes
Since glibc 2.2.3, atexit() (and on_exit(3)) can be used within a
shared library to establish functions that are called when the shared
library is unloaded.
EXAMPLE
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
void
bye(void)
{
printf("That was all, folks\n");
}
int
main(void)
{
long a;
int i;
a = sysconf(_SC_ATEXIT_MAX);
printf("ATEXIT_MAX = %ld\n", a);
i = atexit(bye);
if (i != 0) {
fprintf(stderr, "cannot set exit function\n");
return EXIT_FAILURE;
}
return EXIT_SUCCESS;
}
SEE ALSO
_exit(2), exit(3), on_exit(3)
Linux 2003-11-01 ATEXIT(3)
|