Defined in header <stdlib.h>
void _Exit( int exit_code );
(since C99)
(until C11)
_Noreturn void _Exit( int exit_code );
(since C11)

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.


exit_code - exit status of the program

Return value



#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");
    fflush(stdout);   /* _Exit may not flush unwritten buffered data */


Enter main()


  • C17 standard (ISO/IEC 9899:2018):
    • The _Exit function (p: 256)
  • C11 standard (ISO/IEC 9899:2011):
    • The _Exit function (p: 352)
  • C99 standard (ISO/IEC 9899:1999):
    • The _Exit function (p: 316)

See also

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

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