_Exit

 

C

Compiler support

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
getenvgetenv_s (C11)	system
Memory alignment query
memalignment (C23)
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>
void _Exit( int exit_code );		(since C99) (until C11)
_Noreturn void _Exit( int exit_code );		(since C11) (until C23)
[[noreturn]] void _Exit( int exit_code );		(since C23)

Causes normal program termination to occur without completely cleaning the resources.

Functions passed to at_quick_exit() or atexit() are not called. Whether open streams with unwritten buffered data are flushed, open streams are closed, or temporary files are removed is implementation-defined.

If exit_code is 0 or EXIT_SUCCESS, an implementation-defined status indicating successful termination is returned to the host environment. If exit_code is EXIT_FAILURE, an implementation-defined status, indicating unsuccessful termination, is returned. In other cases an implementation-defined status value is returned.

Parameters

exit_code

-

exit status of the program

Return value

(none)

Example

Run this code

#include <stdlib.h>
#include <stdio.h>
 
/* _Exit does not call functions registered with atexit. */
void f1(void)
{
    puts("pushed first");
}
 
void f2(void)
{
    puts("pushed second");
}
 
int main(void)
{
    printf("Enter main()\n");
    atexit(f1);
    atexit(f2);
    fflush(stdout);   /* _Exit may not flush unwritten buffered data */
    _Exit(0);
}

Output:

Enter main()

References

• C17 standard (ISO/IEC 9899:2018):

• 7.22.4.5 The _Exit function (p: 256)

• C11 standard (ISO/IEC 9899:2011):

• 7.22.4.5 The _Exit function (p: 352)

• C99 standard (ISO/IEC 9899:1999):

• 7.20.4.4 The _Exit function (p: 316)

See also

abort	causes abnormal program termination (without cleaning up) (function)
exit	causes normal program termination with cleaning up (function)
C++ documentation for _Exit