_Exit

void _Exit( int exit_code );

_Noreturn void _Exit( int exit_code );

[[noreturn]] void _Exit( int exit_code );

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

Return value

(none)

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);
}

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