on_exit(3) — Linux manual page


ON_EXIT(3)              Linux Programmer's Manual             ON_EXIT(3)

NAME         top

       on_exit - register a function to be called at normal process

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 │

CONFORMING TO         top

       This function comes from SunOS 4, but is also present in glibc.
       It no longer occurs in Solaris (SunOS 5).  Portable application
       should avoid this function, and use the standard atexit(3)

NOTES         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

       This page is part of release 5.13 of the Linux man-pages project.
       A description of the project, information about reporting bugs,
       and the latest version of this page, can be found at

GNU                            2021-03-22                     ON_EXIT(3)

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