at_quick_exit

 

C

Language

Headers

Type support

Program utilities

Variadic function support

Error handling

Dynamic memory management

Strings library

Algorithms

Numerics

Date and time utilities

Input/output support

Localization support

Concurrency support (C11)

Technical Specifications

Symbol index

 

Program support utilities

Program termination
abort exit quick_exit (C11) _Exit (C99)	atexit at_quick_exit (C11) EXIT_SUCCESSEXIT_FAILURE
Unreachable control flow
unreachable (C23)
Communicating with the environment
system	getenvgetenv_s (C11)
Signals
signal raise sig_atomic_t	SIG_DFLSIG_IGN SIG_ERR
Signal types
SIGABRTSIGFPESIGILL	SIGINTSIGSEGVSIGTERM
Non-local jumps
setjmp	longjmp
Types
jmp_buf

 

Defined in header <stdlib.h>
int at_quick_exit( void (*func)(void) );		(since C11)

Registers the function pointed to by func to be called on quick program termination (via quick_exit).

Calling the function from several threads does not induce a data race. The implementation is guaranteed to support the registration of at least 32 functions. The exact limit is implementation-defined.

The registered functions will not be called on normal program termination. If a function need to be called in that case, atexit must be used.

Parameters

func

-

pointer to a function to be called on quick program termination

Return value

​0​ if the registration succeeds, nonzero value otherwise.

Example

Run this code

#include <stdlib.h>
#include <stdio.h>
 
void f1(void)
{
    puts("pushed first");
    fflush(stdout);
}
 
void f2(void)
{
    puts("pushed second");
}
 
int main(void)
{
    at_quick_exit(f1);
    at_quick_exit(f2);
    quick_exit(0);
}

Output:

pushed second
pushed first

References

• C17 standard (ISO/IEC 9899:2018):

• 7.22.4.3 The at_quick_exit function (p: 255)

• C11 standard (ISO/IEC 9899:2011):

• 7.22.4.3 The at_quick_exit function (p: 351)

See also

abort	causes abnormal program termination (without cleaning up) (function)
exit	causes normal program termination with cleaning up (function)
atexit	registers a function to be called on exit() invocation (function)
quick_exit (C11)	causes normal program termination without completely cleaning up (function)