ATEXIT(3) BSD Library Functions Manual ATEXIT(3)NAMEatexit — register a function to be called on exit
Standard C Library (libc, -lc)
The atexit() function registers the given function to be called at pro‐
gram exit, whether via exit(3) or via return from the program's main().
Functions so registered are called in reverse order; no arguments are
These functions must not call exit(); if it should be necessary to termi‐
nate the process while in such a function, the _exit(2) function should
be used. (Alternatively, the function may cause abnormal process termi‐
nation, for example by calling abort(3).)
At least 32 functions can always be registered, and more are allowed as
long as sufficient memory can be allocated.
The atexit() function returns the value 0 if successful; otherwise the
value -1 is returned and the global variable errno is set to indicate the
[ENOMEM] No memory was available to add the function to the
list. The existing list of functions is unmodified.
The atexit() function conforms to ISO/IEC 9899:1990 (“ISO C90”).
BSD September 6, 2002 BSD