Namespaces
Variants
Views
Actions

_Exit

From cppreference.com
< c‎ | program
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.

Contents

[edit] Parameters

exit_code - exit status of the program

[edit] Return value

(none)

[edit] Example

#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()

[edit] 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)

[edit] See also

causes abnormal program termination (without cleaning up)
(function) [edit]
causes normal program termination with cleaning up
(function) [edit]