on_exit(3) — Linux manual page


on_exit(3)              Library Functions Manual              on_exit(3)

NAME         top

       on_exit - register a function to be called at normal process

LIBRARY         top

       Standard C library (libc, -lc)

SYNOPSIS         top

       #include <stdlib.h>

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

   Feature Test Macro Requirements for glibc (see

           Since glibc 2.19:
           glibc 2.19 and earlier:
               _BSD_SOURCE || _SVID_SOURCE

DESCRIPTION         top

       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         top

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

ATTRIBUTES         top

       For an explanation of the terms used in this section, see
       │ Interface                           Attribute     Value   │
       │ on_exit()                           │ Thread safety │ MT-Safe │

STANDARDS         top


HISTORY         top

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

CAVEATS         top

       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         top

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

COLOPHON         top

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Linux man-pages 6.9.1          2024-05-02                     on_exit(3)

Pages that refer to this page: execve(2)_exit(2)abort(3)atexit(3)exit(3)