ATEXIT(3) | Library Functions Manual | ATEXIT(3)

# NAME

`atexit` —
register a function to be called on exit

# LIBRARY

Standard C Library (libc, -lc)

# SYNOPSIS

`#include <stdlib.h>`

int
`atexit`(void (*function)(void));

# DESCRIPTION

The `atexit`() function registers the given function to be called at program exit, whether via exit(3) or via return from the program's main. Functions so registered are called in reverse order; no arguments are passed. At least 32 functions can always be registered, and more are allowed as long as sufficient memory can be allocated.

# RETURN VALUES

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 error.

# ERRORS

[`ENOMEM`]
  No memory was available to add the function to the list. The existing list of functions is unmodified.

# SEE ALSO

at_quick_exit(3), exit(3), quick_exit(3)

# STANDARDS

The `atexit`() function conforms to ANSI X3.159-1989 (“ANSI C89”).

June 4, 1993 | NetBSD 9.3