on_exit(3)                 Library Functions Manual                 on_exit(3)

NAME
       on_exit - register a function to be called at normal process
       termination

LIBRARY
       Standard C library (libc, -lc)

SYNOPSIS
       #include <stdlib.h>

       int on_exit(void (*function)(int, void *), void *arg);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       on_exit():
           Since glibc 2.19:
               _DEFAULT_SOURCE
           glibc 2.19 and earlier:
               _BSD_SOURCE || _SVID_SOURCE

DESCRIPTION
       The on_exit() function registers the given function to be called at
       normal process termination, whether via exit(3) or via return from the
       program's main().  The function is passed the status argument given to
       the last call to exit(3) and the arg argument from on_exit().

       The same function may be registered multiple times: it is called once
       for each registration.

       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 on_exit() function returns the value 0 if successful; otherwise it
       returns a nonzero value.

ATTRIBUTES
       For an explanation of the terms used in this section, see
       attributes(7).

       +--------------------------------------------+---------------+---------+
       |Interface                                   | Attribute     | Value   |
       +--------------------------------------------+---------------+---------+
       |on_exit ()                                  | Thread safety | MT-Safe |
       +--------------------------------------------+---------------+---------+
STANDARDS
       None.

HISTORY
       SunOS 4, glibc.  Removed in Solaris (SunOS 5).  Use the standard
       atexit(3) instead.

CAVEATS
       By the time function is executed, stack (auto) variables may already
       have gone out of scope.  Therefore, arg should not be a pointer to a
       stack variable; it may however be a pointer to a heap variable or a
       global variable.

SEE ALSO
       _exit(2), atexit(3), exit(3)

Linux man-pages 6.7               2023-10-31                        on_exit(3)