exit, _Exit, _exit

Terminates the calling process. The exit function terminates it after cleanup; _exit and _Exit terminate it immediately.

Note

Do not use this method to shut down a Universal Windows Platform (UWP) app, except in testing or debugging scenarios. Programmatic or UI ways to close a Store app are not permitted according to the Microsoft Store policies. For more information, see UWP App lifecycle. For more information about UWP apps, see Universal Windows Platform documentation.

Syntax

void exit(
   int const status
);
void _Exit(
   int const status
);
void _exit(
   int const status
);

Parameters

status
Exit status code.

Remarks

The exit, _Exit and _exit functions terminate the calling process. The exit function calls destructors for thread-local objects, then calls—in last-in-first-out (LIFO) order—the functions that are registered by atexit and _onexit, and then flushes all file buffers before it terminates the process. The _Exit and _exit functions terminate the process without destroying thread-local objects or processing atexit or _onexit functions, and without flushing stream buffers.

Although the exit, _Exit and _exit calls do not return a value, the value in status is made available to the host environment or waiting calling process, if one exists, after the process exits. Typically, the caller sets the status value to 0 to indicate a normal exit, or to some other value to indicate an error. The status value is available to the operating-system batch command ERRORLEVEL and is represented by one of two constants: EXIT_SUCCESS, which represents a value of 0, or EXIT_FAILURE, which represents a value of 1.

The exit, _Exit, _exit, quick_exit, _cexit, and _c_exit functions behave as follows.

Function Description
exit Performs complete C library termination procedures, terminates the process, and provides the supplied status code to the host environment.
_Exit Performs minimal C library termination procedures, terminates the process, and provides the supplied status code to the host environment.
_exit Performs minimal C library termination procedures, terminates the process, and provides the supplied status code to the host environment.
quick_exit Performs quick C library termination procedures, terminates the process, and provides the supplied status code to the host environment.
_cexit Performs complete C library termination procedures and returns to the caller. Does not terminate the process.
_c_exit Performs minimal C library termination procedures and returns to the caller. Does not terminate the process.

When you call the exit, _Exit or _exit function, the destructors for any temporary or automatic objects that exist at the time of the call are not called. An automatic object is a non-static local object defined in a function. A temporary object is an object that's created by the compiler, such as a value returned by a function call. To destroy an automatic object before you call exit, _Exit, or _exit, explicitly call the destructor for the object, as shown here:

void last_fn() {}
    struct SomeClass {} myInstance{};
    // ...
    myInstance.~SomeClass(); // explicit destructor call
    exit(0);
}

Do not use DLL_PROCESS_ATTACH to call exit from DllMain. To exit the DLLMain function, return FALSE from DLL_PROCESS_ATTACH.

By default, this function's global state is scoped to the application. To change this, see Global state in the CRT.

Requirements

Function Required header
exit, _Exit, _exit <process.h> or <stdlib.h>

For additional compatibility information, see Compatibility.

Example

// crt_exit.c
// This program returns an exit code of 1. The
// error code could be tested in a batch file.

#include <stdlib.h>

int main( void )
{
   exit( 1 );
}

See also

Process and Environment Control
abort
atexit
_cexit, _c_exit
_exec, _wexec Functions
_onexit, _onexit_m
quick_exit
_spawn, _wspawn Functions
system, _wsystem